page 65

4

Housing-Related Health and 

Safety Hazard Assessment 

Resident Interviews

Purpose

Past Experience

Interviewer Staffing

Interviewer Training

Interview Documentation

Quality Control/Quality Assurance

Managing Confidential Data and Resident Concerns for Privacy

Interview Tools

Interview Data Security

Visual Assessment

Purpose—Identify Housing Defects and Causes

Limitations of Visual Assessment and 

Training Needed

Scope 

Sequencing Areas 

Healthy Home Rating System

Specific Housing Conditions to Assess 

Visually

Prioritizing Visual Assessment Results

Environmental Sampling and Measurements

Environmental Sampling Methods—

General Considerations 

Energy Audits
page 66 Housing-Related Health and Safety Hazard Assessment
page 67

4

This simple principle lies at the heart of healthy 

housing initiatives and recognizes interactions 

between housing and disease, injury, and 

overall well being. Identifying unhealthy housing 

conditions is a prerequisite to correcting them 

before they negatively impact health. 

This chapter provides an overview of inspection 

and assessment methods, highlights specific 

tools, and lays the foundation for effective 

and efficient interventions addressed in 

Chapter 5. Home-based health hazards can 

be assessed by: (1) collecting information 

on occupants’ health and housing concerns 

during resident interviews; (2) performing a 

visual assessment; and (3) for some hazards, 

collecting environmental measurements and 

samples (Figure 4.1). The visual assessment is 

the cornerstone of the assessment process and 

can be conducted alone or in combination with 

the resident interview and/or environmental 

Housing conditions should support the health and well-being of its residents; they should not cause injuries or illness. 

Key Messages

• There are three primary ways of identifying 

housing health and safety problems: 

resident interviews, visual assessments, and 

environmental sampling. Visual assessments 

are the foundation of the assessment 

process, while environmental sampling is 

usually limited because of cost constraints. 

• Interviews with residents should be 

conducted by skilled individuals. The 

interview can help to inform the visual 

assessment and environmental sampling, as 

well as provide an education opportunity.

• Program staff performing these functions 

must be trained to carry them out properly, 

understand how to work as an integrated 

team, and know when to refer a problem to 

a more highly trained professional.

• Numerous interview and visual assessment 

tools have been developed. In general, new 

programs should not change validated, 

evidence-based tools. Use of common 

tools ensures consistency. 

• The visual assessment covers moisture, 

ventilation, safety (injury) hazards, 

combustion safety, pest problems, and 

cleanliness. It usually begins with the 

exterior site (including garages), building 

exterior, common areas (if any), building 

equipment rooms, building penetrations 

and proceeds finally to living areas.

Figure 4.1 Assessment Methods

There are three approaches to identifying 

health and safety hazards in the home 

environment:

• Resident Interviews.

• Visual Assessment.

• Environmental Sampling and Building 

Performance Testing.

Housing-Related Health and Safety Hazard Assessment
page 68

measurements. Environmental sampling should 

be used judiciously as it can be costly. The 

Department recognizes the need for local 

jurisdictions to tailor programs based on priorities 

and end users. While programs are encouraged 

to use the best tools to meet their needs, the 

Department is requiring grantees of the Healthy 

Homes Production Grant program to use HUD’s 

Healthy Home Rating System in an effort to 

standardize assessment criteria. In order to 

be considered healthy, a home must support 

the health and well-being of its residents, and 

protect against harm caused by health and 

safety deficiencies. Unless common assessment 

criteria are used, these definitions are subject to 

interpretation and wide variability in practice.

Assessing and remediating health and safety 

risks in housing includes recognizing hazards, 

assessing their importance, and controlling or 

eliminating them. Proper assessment of hazards 

can help your program move to an evidencebased selection of intervention priorities and 

maximize the impact of limited resources for 

housing interventions. It can also enable you 

to determine when a housing unit is in such a 

deteriorated state that it cannot be restored to a 

healthy living environment. Done properly, hazard 

assessment provides the foundation for detailing 

which interventions need to be prioritized based 

on consultations with construction and housing 

rehab specialists. (Figure 4.2). 

Resident Interviews

Purpose

Although some assessments are performed in 

vacant housing, most take place in occupied 

housing units. Gaining the residents’ perception of 

the home environment and their health concerns 

are important sources of information and engages 

them in creating and maintaining a healthier living 

environment. A useful checklist for residents is 

available at: http://www.surgeongeneral.gov/

topics/healthyhomes/checklist.pdf.

a

 Residents’ 

Figure 4.2 Assessing Building Deficiencies and Outcome

Note: The Prioritized Treatment Strategy reflects the focus of your program (e.g., asthma, energy efficiency, injury prevention) as well 

as other factors such as identifying imminent health hazards and risks to occupants, resources, intervention costs, and their relation to 

housing value and level of deterioration. 

Visual

Inspection

Environmental 

Sampling/Buildling 

Performance 

Testing

Construction

and Rehab 

Specialist

Interview

Prioritized

Treatment

Strategy

Analysis of 

Building 

Deficiencies

Housing-Related Health and Safety Hazard Assessment

a

An additional item not included on the checklist is 

ascertaining the thermal comfort of the occupants where 

there may be excess heat or cold due to the lack of 

proper insulation or inadequate heating/air conditioning.
page 69

input can help focus the subsequent visual 

assessment and environmental measurements 

that, in turn, will determine intervention priorities.

Resident interviews that gather information on 

health and environmental problems are useful 

aids but should not replace a thorough visual 

assessment. Resident interviews can provide 

an important opportunity to educate residents 

on what they can do to improve and maintain 

a healthy home. Skilled interviewers not only 

collect data but provide information to residents 

that can motivate and reinforce good health 

behavior and discourage unhealthy practices. 

Past Experience

The report, An Evaluation of HUD’s Healthy 

Homes Initiative: Current Findings and 

Outcomes,

1

 examined over 50 Healthy Homes 

grantees from the first four rounds of grant 

funding (1999–2006). It found 83 percent of 

these programs routinely conducted multiple 

assessments and interviews of clients. Resident 

assessments and interviews usually focused 

on behavioral information (such as smoking 

or cleaning habits), health data (such as 

asthma symptoms), household/resident/family 

characteristics, and the client’s knowledge of 

specific subject matter. The top three types of 

data routinely collected as part of the baseline 

interview were: 

• Behavioral information (88 percent);

• Health data (83 percent); and

• Household/resident/family characteristics 

(81 percent).

Data were collected most commonly on asthma, 

emergency department visits, doctor visits, and 

health-related absences from school or work 

(see Figure 4.3). These health data sets are often 

used to assess child and caregiver quality of life. 

Self-reported data, collected using a validated 

instrument during an interview, contain valuable 

information on health status and have proven to 

be an acceptable way to assess health outcomes 

associated with housing improvements.

Interviewer Staffing

Consider carefully who will conduct the 

interview, keeping in mind the program design 

and local resources. Interview staff can be 

health educators, community health workers, 

community organizers, nurses, social workers, 

environmental health specialists, health 

inspectors, housing code inspectors, physicians, 

or other medical care providers.

Community health workers and organizers are 

outstanding resources for education and many 

aspects of research studies. All data collectors 

should be trained in how to protect confidential 

Figure 4.3 HUD Healthy Homes Programs and Type of Data Collected (n=52)

Source: An Evaluation of HUD’s Healthy Homes Initiative pp. 17–18 and A11–15.

Types of Health Data Collected

Percentage of Grantees

100

80

60

40

20

0

Asthma ER visits Doctor 

visits

Absences Allergies Blood-Pb 

levels

Resp. 

conditions

Injuries Poisonings

87

73

54 50

38

27

21

12

54

Housing-Related Health and Safety Hazard Assessment
page 70

information. It may be difficult for residents to 

share sensitive information with anyone other 

than an objective professional.

Many healthy homes programs use a team 

approach to conduct the assessment—with 

a health services staff person conducting the 

interview and a housing services staff person 

conducting the visual assessment. Some 

programs have integrated these functions 

within one person’s job responsibilities with 

appropriate training and support (see Figure 

4.4). In some communities, language translation 

services are required.

Interviewer Training

It is essential that the person conducting the 

interview be trained to follow the protocol and 

prepared to handle various interview situations. 

Training should include content education, 

Figure 4.4 Examples of Healthy 

Homes Assessment Methods

Kansas City Children’s Mercy Hospital 

Environmental Health Program’s intensive 

assessment takes two hours to complete 

and is conducted by two staff members. 

While the environmental hygienist conducts 

environmental measurements and collects 

samples, another staff member (respiratory 

therapist, health educator or social worker) 

provides education and case management. 

Healthy Homes and Babies Program in 

Cleveland uses computerized tools such as 

PDAs (personal data assistant) and tablet 

personal computers to collect environmental 

assessment data. The computerized 

assessment tool guides the inspection in 

each area of the home, documents building 

and behavioral conditions through dropdown alternatives to document observations, 

lists options for corrective actions, and can 

specify the responsible party for each.

Environmental Health Watch (EHW) in 

Cleveland uses visual assessments as an 

opportunity for occupant education. As EHW 

inspectors conduct the assessment, they are 

accompanied by the resident and provide 

education on identified hazards, intervention 

options, and resident responsibility.

Figure 4.5 Promotoras: Healthy 

Homes Training Model

Esperanza Community Housing Corporation 

in South Central Los Angeles employs 

community health promoters—promotoras—

to conduct outreach, education, case 

management, and environmental assessments. 

Promotoras have been found to be effective 

in reaching underserved populations through 

peer education since they are members of the 

communities they serve and speak the same 

language. The promotoras participate in a sixmonth intensive Community Health Promoters 

Training program and receive ongoing 

specialized healthy homes education.

Housing-Related Health and Safety Hazard Assessment

role playing, an explanation and practice of 

standardized methods of documentation, and 

cultural competence. The training should also 

teach interviewers and other healthy homes 

professionals to understand the limits of their 

expertise, such as when to refer a suspected 

problem to a structural engineer or medical 

professional (see Figure 4.5).

Interview Documentation

Documentation calls for recording information 

in a manner that is accurate, legible, and 

understandable so that others can interpret the 

results. The following guidelines are helpful:

• Entries onto interview data collection forms 

(and all other data collection forms) should be 

made in ink. 

• Any corrections should be made with a single 

line through the mistaken entry and initialed 

by the interviewer. 

• Interviewers should also sign and print their 

names on the forms in case clarifications are 

needed. This practice promotes a sense of the 

importance of the data collected. 

• Provide a “notes” section on the form where 

any pertinent information, including deviations 

from the standard interview method, can be 

recorded. No interview form can fully capture 

all potentially important information.

Much of this data collection is now automated 

through the use of computer tablets and other 
page 71

electronic data collection devices. This reduces 

the time needed for data entry and can also 

reduce data entry errors. Using a centralized 

database to upload data can also save time and 

prevent errors.

Quality Control/Quality Assurance

A supervisor or project coordinator should 

review documentation periodically for 

completeness and conduct quality control 

site visits to observe interviews and provide 

training and support if needed. When interview 

information is entered into a database, quality 

control checks should be included in the data 

management protocol. This might include 

randomly reviewing data to ensure that the data 

entered match the data on the forms, doublekeyed data entry (data entered twice), or using a 

statistical program that can be programmed to 

check data accuracy, such as ACCESS. 

Quality assurance procedures should also 

be included in the interview process. For 

example, some interviews can be observed by a 

supervisor to determine whether the interview 

results are properly recorded, all questions 

are being asked, and if the interviewer has 

established a relaxed but thorough interaction 

with the person being interviewed.

More broadly, programs should have a Quality 

Assurance Plan (QAP) in place to ensure that 

all program activities are consistent with 

established program plans and carried out in 

the most effective and cost efficient manner 

possible. A QAP template that should be used 

by HUD Healthy Homes programs is available 

at http://www.hud.gov/offices/lead/hhi/hhts.

cfm. The QAP, which is most appropriate for 

programs that are conducting rigorous outcome 

evaluations, has four components:

• Project Management Plan

• Measurement/Data Acquisition Procedures

• Assessment/Oversight Activities 

• Data Verification and Usability Confirmation

Managing Confidential Data and 

Resident Concerns for Privacy

The interview provides an opportunity to help 

residents understand the scope of the program 

and what it will and will not do. It also points to 

housing conditions that will be considered for 

interventions. The interviewer should inform 

the resident about how the data will be used 

and delineate how private and confidential 

information will be protected. Although a 

research project involving an Institutional Review 

Board (IRB) will likely require more formalized 

protection of this information at a later date, 

the resident’s expectation of confidentiality 

should be explicitly confirmed by the interviewer 

at the beginning. Regardless of whether a 

given project is under the purview of an IRB, 

which ensures the privacy and ethical nature 

of research studies, the interviewer should 

make it clear that residents are not required to 

answer any question they feel uncomfortable 

with, and that they can stop the interview at 

any time. Individuals attending the interview, 

including translators, should also understand the 

confidential nature of the process. The interview 

must be conducted in a professional, courteous 

manner that respects the resident’s dignity and 

culture. Data should be securely stored and 

managed; access to the data should be limited 

and electronic data should be stored in secure, 

password protected files.

Interview Tools 

There are several healthy homes interview 

instruments that have been field-tested and 

found useful in characterizing health status and 

housing conditions (see Figure 4.6). One is the 

HUD/CDC Healthy Homes Inspection Manual.2 

A longer, more detailed instrument designed 

for research projects is drawn from the CDC 

National Health Interview Survey and other 

national surveys and was developed jointly by 

the National Center for Healthy Housing and 

CDC staff. Variations of this instrument have 

been used in two studies that document health 

improvements associated with green, healthy 

housing rehabilitation of low-income housing 

and elsewhere. 

Each has strengths and weaknesses. Healthy 

homes programs should evaluate existing tools 

and methods to determine which elements of 

each can be adapted to their programs and 

local conditions. For example, the SeattleKing County interview is focused on asthma 

while Cleveland’s interview focuses on mold 

and moisture. If existing tools are not used, 

Housing-Related Health and Safety Hazard Assessment
page 72

interview instruments need to be developed 

with your program’s housing intervention and 

desired outcome in mind. Be mindful that if 

you change a tool that has been widely used, 

your changes may compromise its reliability. In 

general, creating your own assessment tool is 

not recommended.

Interview Data Security

Completed interview forms may contain 

personal information. To prevent inadvertent 

disclosures of this information, secure the 

data by keeping forms in a locked file cabinet 

or a locked room, limiting access to the data 

to specified staff, and establishing a data 

retention schedule to destroy the information 

at a designated time after the project ends. 

Unique identifiers can be used to protect an 

interviewee’s identity. Finally, anyone who 

collects or has access to personal health 

information should sign a confidentiality 

agreement that such information should not 

be disclosed to unauthorized parties. Training 

on protection of human subjects is available at: 

http://phrp.nihtraining.com/users/login.php.

Visual Assessment

Purpose—Identify Housing Defects 

and Causes

Visual assessments by trained individuals have 

emerged as the primary assessment tool for 

most housing conditions related to health (see 

Figure 4.7). This system works best for visible 

hazards such as missing or deteriorated building 

components and systems. It can also identify 

causes of hazards and how they are likely to be 

remediated. The visual assessment should be 

integrated with the interventions (discussed 

in Chapter 5). Missing hand railings, leaking 

pipes under a kitchen sink, and openings that 

permit pest entry are obvious examples of 

problems amenable to visual examination. 

There is an emerging consensus that most 

mold problems can be identified by a visual 

assessment. Of course, the eyes are not the 

only senses that should be used. For example, 

mold is often associated with a musty odor 

and has been linked with adverse respiratory 

health outcomes in large studies.3, 4 The rottenegg odor of hydrogen sulfide from sewer gas 

is also well known. The odor of natural gas 

can indicate a dangerous gas leak. Although 

some protocols have a simple “yes” or “no” 

response, most conditions require some 

assessment of the severity of each observed 

hazard. Digital photography of units can be 

helpful in documenting specific conditions. 

Programs should obtain permission from the 

resident to take photographs, which should 

then be included in the project file with other 

documentation.

Limitations of Visual Assessment 

and Training Needed

Visual assessments should be performed only 

by trained personnel and criteria should be 

developed for enlisting specialized assistance 

(Figure 4.8 describes one source of available 

training). Some housing hazards are not 

amenable to sight and smell assessment. For 

example, the pipe leak under the kitchen sink 

may not be obvious if the leak begins three 

Housing-Related Health and Safety Hazard Assessment

Figure 4.6 Examples of Healthy 

Homes Interview Instruments

• Healthy Homes Inspection Manual (Section 1)

• NCHH adaptation of National Health 

Interview Survey for Housing Conditions

• Boston, MA Healthy Homes Interview

• Cuyahoga County, OH (near Cleveland) Mold 

and Moisture Interview

• Seattle-King County, WA HomeBASE 

Interview

• New York State Healthy Neighborhoods

• Newport, RI Healthy Homes Health and 

Visual Assessment

• Healthy Homes Training Center: Pediatric 

Environmental Home Assessment.

• NIEHS Injury Assessment Questionnaire

• SF-8 Quality of Life Survey http://www.sf-36.

org/tools/sf8.shtml

• Allies Against Asthma, Asthma Core 

Caregiver Survey http://asthma.umich.edu/

media/eval_autogen/core_caregiver.pdf
page 73

levels up or the water is pooling behind a 

wall and the leak is sporadic, which might 

be the case for an infrequently used drain. 

Radon and carbon monoxide are examples of 

contaminants that cannot be assessed visually. 

To assess hidden structural defects, programs 

may need to employ engineers or electricians 

when problems include inadequate or missing 

grounding or other faulty wiring.

Scope

Visual assessments can evaluate many structural, 

environmental, and behavioral risk factors. 

For example, many ventilation problems can 

be identified visually, such as inoperable bath 

or kitchen exhaust fans or disjointed flues on 

water heaters (a structural problem). However, 

if the bath fans are operational and there is 

still a large mold problem, it may be that the 

resident is not turning the exhaust fan on when 

needed or it may not be ducted to the exterior. 

Similarly, no amount of ventilation will prevent 

the health hazards associated with tobacco 

smoking (behavioral problem). In short, visual 

assessments can provide clues to occupant 

behavior that can cause or exacerbate hazards.

Visual assessments should document the tenure 

of the unit (rental versus owner-occupied), 

if the unit is occupied or vacant, the type of 

structure (such as manufactured housing, or 

duplex, single- or multi-family housing), type 

of ventilation and air conditioning system, type 

of foundation, and whether the basement is 

treated as a living space.

How your program performs a visual assessment 

depends to some extent on your target housing. 

For example, assessing the structural condition 

of row homes may differ from stand-alone single 

family housing due to the presence of shared 

walls. If the dwelling is a multi-family home, the 

common areas (if present) should be included in 

the visual assessment. Similarly, if the dwelling 

is a mobile home, it might be prudent to check 

the tie-down systems. Tie-downs are an example 

of why the assessment should be driven by the 

type and location of housing. In earthquake 

zones, for example, seismic retrofits may be 

needed.

The type of water supply and sewage system 

should be determined. In rural areas, well water 

should be tested periodically to ensure it is 

potable and tile fields/septic systems may need 

assessment for adequate treatment of waste 

water. Crawl spaces and attics should also be 

included in the visual assessment. 

Sequencing Areas 

Experience and studies have found a standardized 

sequence increases the accuracy of an assessment 

and reduces omissions when pinpointing building 

deficiencies. Checklists and/or documentation 

should mirror the sequence. Figure 4.9 and the 

Figure 4.7 Most Frequent Hazards 

Identified by Visual Assessments

An Evaluation of HUD’s Healthy Homes 

Initiative: Current Findings and Outcomes

reported 81 percent of 51 Demonstration 

and Technical Studies programs conducted 

visual assessments. The five most frequently 

reported hazards assessed included: 

• Presence of visible mold and moisture 

problems (96 percent);

• Pest infestation (82 percent);

• Lead hazards/chipping peeling paint 

(72 percent);

• Fire hazards (69 percent); and 

• Carbon monoxide hazards (67 percent). 

An Evaluation of HUD’s Healthy Homes Initiative, 

2007, pp A9–11.

Figure 4.8 Training for Healthy 

Homes Practitioners

The National Healthy Homes Training 

Center’s Essentials for Healthy Homes 

Practitioners course provides an introduction 

to the concept of the house as a system. 

The course prepares participants for a 

comprehensive exam to receive National 

Environmental Health Association 

accreditation as a Healthy Homes Specialist. 

The training is not required to sit for the 

exam. See http://www.nchh.org/Training/

National-Healthy-Homes-Training-Center.

aspx

Housing-Related Health and Safety Hazard Assessment
page 74

Figure 4.9 Recommended 

Sequence for Visual Assessments

1. Site (including entrance and egress).

2. Garages (attached and non-attached) 

and other site structures (e.g., sheds and 

fences) and facilities (e.g., swimming pools, 

play areas).

3. Building exterior.

4. Common areas (multifamily housing only).

5. Equipment rooms (HVAC, laundry, 

basements, crawl spaces, attics).

6. Kitchens.

7. Baths.

8. Living areas.

9. Bedrooms.

following discussion detail a recommended 

sequence enabling inspectors to examine areas 

methodically and assess common features 

efficiently.

First, examine the general site on which the 

building is located for common hazards such 

as pooling of water, damaged fencing (or lack 

of fencing, especially around swimming pools), 

erosion, extensive plant overgrowth, sidewalk 

cracks, and safety of play area equipment. 

Inspect garages and other structures during this 

phase of the inspection.

Second, examine the building envelope (walls, 

roofs, doors, windows, etc.) and exterior for 

items such as: leaks from deteriorated caulk; 

gaps in doors that might enable pest entry or 

water incursion; broken or inoperable windows; 

bulging walls; sagging rooflines; damaged or 

missing trim (fascia and soffits) or flashing; and 

problems with gutters.

Third, examine the “guts” of the home, which 

consists of the equipment room where the 

HVAC (heating, ventilation, and air conditioning), 

laundry, electrical, and other systems are 

located. Items such as fuel leaks, misaligned flue 

vents, the absence of makeup air (e.g., air that 

is supplied to a space to replace the air that is 

exhausted), damaged or frayed electrical wiring 

or burn marks on fuse or electrical breaker 

boxes, and faulty fire protection systems (e.g., 

painted-over sprinkler heads) are examples of 

items to be examined. 

Fourth, proceed into the living area of the house 

itself, which can be divided into “wet” rooms 

(kitchens and baths), bedrooms, and living areas. 

Some of the items to be assessed in these areas 

include leaks and drains; cracks in walls, floors 

and ceilings; water temperature (120o Fahrenheit 

or lower); trip hazards; paint condition; mold; 

overuse of extension cords (overloaded circuits); 

broken electrical sockets; presence of unvented 

fuel-fired space heaters; and inadequate food 

preparation, storage, and disposal facilities. 

Evidence of pests, such as mice and cockroach 

feces (frass), is typically assessed in these 

locations. Smoke and carbon monoxide alarm 

operation should always be tested. Visual 

assessment should include the stairways that 

service the living space.

Fifth, examine all penetrations into the house 

from the inside to the exterior. Healthy homes 

inspectors should be trained to recognize the 

limits of their expertise. For example, they should 

not touch electrical systems unless adequately 

trained. Inspectors should also avoid tracking 

contaminants, soil or dirt from one area to 

another (e.g., from crawl spaces into bedrooms). 

Some ventilation problems require specialized 

building science or engineering expertise. 

Training in lead risk assessment is recommended 

and required by most jurisdictions for assessment 

of lead-based paint hazards. 

Healthy Home Rating System

While programs are encouraged to use the best 

tools to meet their needs, HUD is requiring 

grantees of the Healthy Homes Production 

Grant program to use HUD’s Healthy Home 

Rating System (HHRS) in an effort to standardize 

assessment criteria. The HHRS is categorized 

in accordance with the American Public Health 

Association’s 1938 publication entitled, “Basic 

Principles of a Healthful Housing.” Using the 

HHRS, the assessor examines 29 hazards, or 

categories of hazards, and determines the risk 

to the occupant (i.e., the likelihood of hazard 

causing harm and the severity of the harm 

should it occur) for each hazard that is identified 

Housing-Related Health and Safety Hazard Assessment
page 75

(see Figure 4.10 and Operating Guidance at: 

http://www.hud.gov/offices/lead/hhrs.cfm). Each 

of the 29 hazards are assessed separately and 

weighted according to likelihood of occurrence 

and the severity of possible outcomes should the 

hazard result in harm (i.e., a risk-based approach 

in which a numerical value is generated for each 

hazard). The HHRS is available for use by those 

not receiving HUD grant funds, as well.

A priority ranking of hazards is generated 

based on the estimated risks of potential harm 

to the most vulnerable occupants. Inspections 

are essentially carried out in the traditional 

fashion (i.e., a physical assessment of the whole 

property for deficiencies) using a portable 

computer with specialized software. The HHRS 

follows the same approach to identifying health 

and safety hazards in the home as successfully 

implemented in the British “Housing Health and 

Safety Rating System” (http://www.communities.

gov.uk/publications/housing/housinghealth). The 

basic principle is that the property should be 

safe and healthy for all occupants. 

The assessment using the HHRS is made based on 

the condition of the whole dwelling. This means that, 

before such an assessment can be made, a thorough 

inspection of the dwelling must be carried out to 

collect the evidence of the condition. While this 

does not involve a new approach to the inspection 

of dwellings, it does require an understanding and 

appreciation of the potential effects that could result 

from conditions and deficiencies that should have 

been identified during the inspection.

The HHRS concentrates on threats to health and 

safety. It is generally not concerned with matters 

of quality, comfort and convenience. However, 

in some cases, such matters could also have an 

impact on a person’s physical or mental health 

or safety and so can be considered. Also, as 

the Rating System is about the assessment of 

hazards (the potential effect of conditions), the 

form of construction and the type and age of 

the dwelling do not directly affect the approach 

taken in the assessment. The age of the dwelling 

would be a consideration when assessing for 

lead hazards, for example, but would not alter 

the overall approach taken in terms of evaluating 

the hazards present. Matters related to age 

and type of construction will be relevant to 

determining the cause(s) of any problem and so 

indicate the nature of any remedial action.

The HHRS has been devised and designed so 

that it can be applied to any form of dwelling. To 

achieve this, it is only necessary to inspect and 

assess the dwelling and those parts and areas 

(whether shared or not) that are associated with 

that unit. 

Once the inspection has been completed, the 

Housing-Related Health and Safety Hazard Assessment

Figure 4.10 Healthy Home Rating System (HHRS)—Categorization of 29 Hazards

Physiological Psychological Infection Safety

1. Dampness & Mold 

 Growth 

2. Excess Cold 

3. Excess Heat 

4. Asbestos and man-

 made fibers 

5. Biocides 

6. Carbon Monoxide 

7. Lead-based paint

8. Radiation 

9. Un-combusted fuel

10. Volatile organic 

 compounds

11. Crowding and Space 

12. Entry by Intruders 

13. Lighting

14. Noise

15. Domestic Hygiene, 

 Pests, and Refuse 

16. Food Safety 

17. Personal Hygiene

18. Water Supply

19. Falls in baths etc. 

20. Falls on the level 

21. Falls on stairs etc. 

22. Falls from windows 

 etc. 

23. Electrical hazards 

24. Fire hazards 

25. Hot surfaces etc. 

26. Collision/

 Entrapment 

27. Ergonomics 

28. Explosions

29. Structural collapse
page 76

inspector makes the assessment. This involves:

(a) determining whether there are any 

deficiencies present by assessing whether 

each dwelling element and the dwelling as a 

whole meets the relevant Ideal;

(b) determining whether any deficiencies 

contribute to one or more hazards, and if so, 

which hazards; and

(c) for each hazard which is obviously worse than 

average for that type and age of property, the 

inspector assesses:

i) the likelihood of an occurrence over the 

next twelve months; and

ii) the probable spread of harms which could 

result from such an occurrence.

It is important to note that the HHRS only 

assesses the physical aspects of the home; it does 

not collect information on occupant behavior 

that can contribute to some hazards (e.g., 

misuse of pesticides), nor does it incorporate 

environmental sampling results. If desired, 

programs can supplement the HHRS with a 

resident questionnaire and a plan for collecting 

environmental samples and measurements.

For more information on the Healthy Homes 

Rating System, refer to the Operating Guidance 

available at www.hud.gov/healthyhomes.

Major Housing Conditions to Assess 

Visually

Conditions to be assessed visually include:

• Moisture

• Ventilation Systems and Combustion Sources

• Safety Hazards

• Structural Defects

• Insulation and Temperature Regulation

• Pest Infestation*

• Cleanliness and Clutter

(*Investigation of pest problems is also 

covered in the building performance section 

of this chapter, because it involves the use of 

certain traps and other tools. A more complete 

discussion appears in the HUD/CDC Healthy 

Homes Inspection Manual5 and the HUD/CDC 

Healthy Housing Reference Manual.

6

 Additional 

technical information is available in EPA’s Indoor 

airPLUS Construction Specifications: www.epa.

gov/indoorairplus/construction_specifications.

html).

Moisture

Excessive moisture in housing has been related to 

a number of adverse health outcomes. Structural 

rot, rust, and other degradation can result in 

physical injury hazards as well as slips and falls 

from slippery surfaces. Moisture in housing can 

amplify indoor levels of biological agents such as 

mold, dust mites, and pest populations, many of 

which can trigger asthma and allergy symptoms.7

Excessive moisture is also one of the leading 

causes of deteriorating lead paint.

Many moisture problems can be identified visually:

• Look for discolored or wet walls ceiling and 

walls;

• Identify missing or damaged downspouts and 

gutters;

• Check for ponding near foundations;

• Examine exteriors for holes and cracks;

• Look underneath sinks for drain and plumbing 

leaks;

• Determine if air conditioner condensate drains 

are operating and sloped;

• If humidifiers are present, determine if they 

are clean;

• Look for condensation on windows in cold 

weather; and

• Look in basements for water damage and entry.

In addition, while there may not be obvious 

visible signs of moisture, the presence of a strong 

musty smell may indicate the presence of mold 

from excess moisture/water leaks. The National 

Academy of Sciences examined the association 

between exposures to biologic agents in the 

home and the development and exacerbation of 

asthma. The review found sufficient evidence to 

establish a causal association between asthma 

and dust mite exposure as well as between 

asthma exacerbation and the presence of 

Housing-Related Health and Safety Hazard Assessment
page 77

dust mites, cockroaches, fungi (mold), and pet 

dander.8, 9 There is also evidence of associations 

between excessive moisture and other adverse 

respiratory outcomes.10 Mice and cockroaches 

spread allergens that can trigger asthma suffered 

by both inner-city and suburban children.11, 12, 13

Moisture problems can be typically assessed 

by trained individuals through direct visual 

observation. The CDC/HUD Healthy Housing 

Inspection Manual identifies moisture-related 

building deficiencies such as discolored ceiling 

tiles, presence of visible condensation (may 

only occur in the winter), missing or damaged 

downspouts and gutters, pooling of water 

near foundations, presence of holes or cracks 

in building walls, plumbing systems that have 

inadequately insulated cold water pipes (leading 

to condensation), and sewage and water drain 

and supply leaks. Clearly, there are many ways 

in which water can enter a building (Figure 4.11). 

Some programs find that using a simple moisture 

meter helps identify moisture problems along 

with visual assessment (Figure 4.12).

Homes equipped with air conditioning systems or 

dehumidifying systems require attention to ensure 

that condensate drains do not become blocked or 

contain mold. Additionally, condensate pans need 

to be properly sloped so that the water runs to the 

drain and does not pool in other areas. Keeping 

coils clean can reduce contaminants in the air and 

also promote energy efficiency.

Housing-Related Health and Safety Hazard Assessment

Figure 4.11 Ways in Which Water Can Enter a Building (Envelope leaks can occur 

from anywhere in the building roof, windows, walls, doors and penetrations)

Figure 4.12 Moisture Meters as an 

Adjunct to Visual Assessment of 

Moisture Problems
page 78

Unvented combustion appliances, such as 

unvented space heaters and unvented fireplaces, 

can introduce substantial amounts of moisture 

and other combustion products (depending on 

whether the appliances are properly functioning) 

into the home whenever the devices are in use.

Some HVAC systems are equipped with 

humidifiers, especially in northern climates where 

indoor winter air can be very dry; sometimes 

individual rooms may be equipped with room 

humidifiers. In southern climates, the systems 

may be fitted with a dehumidifier to remove 

moisture before the conditioned air enters 

the home. In both cases, the water supply, 

water tank, water pads, water wheels, or other 

distribution systems need to be maintained. If the 

systems are not used regularly, they can breed 

biological agents such as mold and bacteria. 

Drafty homes are often too dry in the winter 

and too humid in the summer, depending on the 

climate region. The resident interview can help 

to determine if there is excessive dryness in the 

winter and whether boiling pots of water or other 

measures are used as “home-grown” humidifiers, 

which may lead to mold problems. 

Aside from floods, sources of water and 

moisture in homes include structural leaks 

(e.g., roof leaks), plumbing leaks, condensation, 

damp foundations and crawl spaces, inadequate 

ventilation, and activities such as bathing 

and cooking. Condensation is often linked to 

inadequate insulation, inadequate vapor barriers 

(in cold climates) and/or poor ventilation. Unless 

moisture-laden air is exhausted from the home, 

building envelopes that are “tightened” for 

energy conservation purposes may lead to 

excessive indoor moisture levels.

Other sources of moisture can foster problems, 

such as capillary action that “wicks” moisture 

from basement floors up into certain types 

of walls (such as drywall, paneling, or other 

cellulose-based materials touching concrete 

basement floors). Excessive crowding may also 

produce high moisture levels.

Interior moisture levels are strongly influenced by 

exterior conditions, making a uniform definition 

of acceptable interior moisture levels dependent 

on climate zones. In general, maintaining an 

indoor relative humidity between 30–50 percent 

(lower in the winter and higher in the summer) 

optimizes comfort and improves indoor air quality 

by reducing dust mite and mold growth. Water 

content (sometimes called “water activity”) of 

building components can be measured with a 

moisture meter (Figure 4.12) but be mindful of 

the fact that building materials have differing 

amounts of water activity. For example, plaster or 

concrete hold much more water than drywall, so 

interpreting moisture meter readings is typically 

dependent on the type of material.

Local exhaust ventilation for bathrooms and 

kitchens should be present and properly 

installed and maintained, and, of course, actually 

used. Many building codes do not require such 

systems if windows are present. However, if 

windows are kept shut during peak water use 

(such as bathing when the outdoor temperature 

is too cold or hot), moisture has nowhere to go 

other than the rest of the living area. Kitchens 

also benefit from local exhaust by removing 

excess moisture from cooking and by removing 

combustion gases from fuel-fired stoves and 

ovens.

If installing new fans, use quiet “low sone” 

Energy Star-rated products, because residents 

are less likely to use noisy fans. Moist air should 

be exhausted to the outside, never into a 

building cavity, attic, basement, or crawl space. 

New and rehabilitated houses increasingly 

equip local exhaust fans with timed humidistats 

that automatically operate the exhaust fans 

when moisture increases to a certain level. This 

conserves energy and reduces the need to rely 

on resident behavior. Fans should be properly 

sized (Figure 4.13). 

Housing-Related Health and Safety Hazard Assessment

Figure 4.13 Fans Should Fit the 

Building Configuration

The American Society of Heating, Refrigerating, and Air Conditioning Engineers 

(ASHRAE) recommends that kitchen fans 

exhaust 100 cubic feet per minute (cfm) and 

bathroom fans exhaust 50 cfm (see http://

www.ashrae.org/technology/page/548). 

Actual fan performance depends on the duct 

configuration and other factors that contribute to the pressure drop (resistance) in the 

system. For example, a fan rated at 50 cfm 

located in a basement bathroom that has to 

push air through several stories before being 

exhausted may not move sufficient air. 
page 79

When installing exhaust ventilation for kitchens 

and baths, the issue of supply (makeup) air 

matters. If sufficient makeup air is not available, it 

can create negative pressure in the home. If there 

are combustion appliances, this negative pressure 

can cause “backdrafting”—the reversal of airflow 

in chimneys, water heaters, and other devices. 

Backdrafting results in carbon monoxide and 

other combustion products being released into 

the living space. An example of makeup air is the 

passive or powered delivery of outside air into a 

basement that has a furnace, boiler, or gas water 

heater. Another is a heat recovery ventilator that 

permits tempering of the outside air supply using 

the energy of air being exhausted. Both examples 

involve a planned fresh air supply to replace the 

exhausted air (Figure 4.14).

Exterior Grading and Pooling

Water penetration into a building often occurs 

at the foundation and ground level. Evidence of 

standing water, pooling, or erosion usually means 

failure to slope and grade the soil and ground 

properly around the foundation (Figure 4.15). 

Maintaining proper grading around a foundation 

can prevent moisture intrusion into basements and 

the need for expensive foundation waterproofing 

and excavation. Proper grading also supports 

the durability of the structure by reducing the 

prospect of settling that leads to cracks. 

Ground Treatment

Bare earth floors in a basement or crawl space should 

be covered with a durable vapor retarder—such as 

6 mil or thicker polyethylene plastic—covering the 

entire soil area and sealed to the foundation walls and 

piers. In some parts of the country, a thin concrete 

slab is poured over the poly to protect it. Called a “rat 

slab,” the concrete prevents rodents from burrowing 

through the poly and entering the space. The visual 

assessmentshould determine if the bare earth is 

covered.

Water Pipes

Water pipes located in unconditioned areas 

should be insulated to prevent condensation. 

One way of detecting this problem is to look for 

areas of discoloration where condensation from 

pipes has dripped onto a lower surface. The 

same principle applies to ductwork that carries 

warm or cold air through air zones with a high 

temperature gradient. 

Ductwork

All ductwork should be sealed and well insulated. 

To prevent condensation, the insulation should 

be protected by a vapor retarder depending on 

the climate zone. Insulation should be applied to 

the exterior of the ductwork to keep insulation 

fibers out of the air stream and reduce the 

opportunities for dirt and debris to build up 

inside the ductwork, which creates a habitat for 

mold and other organisms. While insulation of 

ductwork is a simpler matter in new construction, 

poor insulation of ductwork in older housing can 

result in condensation and become a significant 

breeding ground for mold and other biological 

agents.

Flashing

The absence or deterioration of flashing is a 

common building deficiency associated with 

Housing-Related Health and Safety Hazard Assessment

Figure 4.15 Moisture Problems Caused 

by Improper Ground Slopes

Figure 4.14 Backdraft Deficiencies
page 80

water leakage through the building envelope. 

Flashing refers to thin continuous pieces of 

sheet metal or other impervious material 

installed to prevent water from leaking into a 

structure through an angle or joint. Flashing is 

appropriate in numerous building situations: 

• Roof penetrations such as chimneys;

• Places where walls meet a roof line;

• Valleys between opposing roof surfaces;

• Wall penetrations such as windows or 

ventilation hoods; and

• Other structural discontinuities such as 

additions.

When new building components such as windows 

are installed, they should be installed with 

flashing to prevent moisture intrusion. The key 

design requirement of flashing is its assembly 

in a manner that allows flashing layers to use 

gravity to shed water rather than rely on caulks 

or sealants. The principle of flashing should be 

extended to all penetrations in structures—i.e., 

they should be sealed to prevent moisture and 

pest incursion into the living space. Moisture 

meters and visual assessment can sometimes 

be used to assess the adequacy of flashing, 

although it is not always possible to see if flashing 

is present without removing building coverings, 

which is not recommended. If moisture meters 

or visual assessment results identify building 

components with excessive moisture, defective 

or absent flashing may be a cause.

Condensation

Evidence of window condensation also deserves 

special consideration (Figure 4.15). Depending 

on the indoor and outdoor temperature and 

humidity levels, condensation may not be present 

at the time of an inspection. Condensation can 

occur when air that is sufficiently warm and moist 

comes in contact with a cold surface. The water 

created through condensation can lead to mold 

and other problems that create both health 

hazards and building decay.

Condensation often occurs on windows because 

the window is not adequately insulated and 

it is the coldest surface. Modern double- and 

triple-pane windows, some filled with inert 

gases between the panes, effectively eliminate 

condensation problems on windows when 

properly configured for the specific building 

application, orientation, and climate. Such window 

replacement also has the benefit of removing a 

major source of lead-based paint exposure, as 

old single pane windows are known to have the 

highest levels of lead-contaminated dust and paint 

of any other building component. If old windows 

coated with lead-based paint are replaced, leadsafe work practices must be used.14 

Sometimes condensation occurs within the walls, 

ceilings, and floors that separate the outside 

unconditioned air from the conditioned air inside 

the structure as warm moist air travels through 

the cavity. Crawl spaces, attics, and exterior 

walls can be subject to such condensation.

In some cases a vapor retarder—often called 

a vapor barrier—is recommended to inhibit 

condensation or other sources of moisture 

intrusion by reducing the movement of moistureladen air into walls, ceilings and floors. However, 

vapor retarders require some careful thought 

and are dependent on climate zone and other 

factors. If an insulated wall has materials on both 

the interior and exterior surfaces that retard vapor 

movement, moisture can become trapped within 

the wall cavity and cause a serious problem. Walls 

should be designed to have the ability to dry in at 

least one direction. If a mold problem is identified, 

vapor retarder problems may be the cause.

Drains

As important as entry of excess moisture into 

a building is, how water exits the housing 

structure is equally as important. Drains are 

often overlooked as important sources of 

moisture because the leak may be a slow one. 

Drain traps, like all plumbing, deteriorate over 

time. If drain traps are not kept full of water, 

harmful soil or sewer gases can enter the living 

area. If an odor is detected, dry drain traps may 

be the cause. Basement floor drain traps should 

be kept full by periodically adding water into 

them (Figure 4.16).

Other Moisture Sources

Metal windows and door casings directly 

touching sheetrock can lead to moisture 

problems. Inadequate insulation or leaks from 

old caulking can be related to condensation and 

moisture problems. Furniture that is pushed up 

directly against exterior walls, especially in rooms 

Housing-Related Health and Safety Hazard Assessment
page 81

that are below grade, can foster mold growth by 

reducing air movement. Inadequate ventilation 

and moisture problems are often closely related. 

The following sections on ventilation and 

environmental sampling and building testing 

contain additional information on identifying 

moisture and ventilation problems.

Ventilation System and Combustion Sources

Many ventilation system problems can be 

identified visually.

• Look for discoloration on carpets under 

doors. This suggests air pressure differences 

between the two rooms may be too high (i.e., 

the carpet is acting as a filter for the air as 

it moves from the higher to lower pressure 

space).

• Check for pooling or ponding of water near air 

intakes that may cause moisture to infiltrate 

the building. 

• Check whether an attached garage has 

doors that lack seals or other holes between 

the garage and living space. This allows for 

carbon monoxide (CO) and other combustion 

by-products and Volatile Organic Chemicals 

(VOCs) to enter the living space. 

• Identify whether an exhaust vent is located 

too close to a supply vent. If so, the air can 

be “short-circuited,” meaning that instead 

of mixing with the supply air and diluting 

contaminants, it enters the room and is 

immediately exhausted.

Housing-Related Health and Safety Hazard Assessment

Figure 4.16 Floor Drain Traps • Identify ducting problems (too many twists 

and turns), disconnected ducts, and leaky 

ductwork.

• Identify misaligned, cracked, corroded or 

disconnected chimney and water heater flues.

• Check that bathroom, dryer, kitchen, and 

bathrooms have exhaust systems. 

• Make sure all the exhaust ducts go all the way 

through the building envelope to the exterior, 

especially clothes dryers and kitchen and 

bathroom exhaust.

• Identify any unvented combustion appliances 

and determine if all existing combustion 

appliances are vented properly. 

• Make annual inspections of gas and wood and 

other fuel burning appliances and their venting 

systems to prevent poisoning by combustion 

gases.

• Assess homes for the presence of properly 

working carbon monoxide and smoke alarms 

located near all sleeping areas.

• Additional information on testing ventilation 

systems is covered in the Building 

Performance section of this chapter.

Safety/Injury Hazards 

Injury hazards can be identified through home 

safety questionnaires and/or home inspections 

such as those detailed in the HUD/CDC Healthy 

Housing Inspection Manual. Questionnaires 

focusing on the presence or absence of certain 

safety devices (e.g., CO alarms, smoke alarms, 

ground fault circuit interrupters (GFCI) and arc 

fault circuit interrupters)are generally more 

reliable than responses to questions about 

safety practices (e.g., safe medicine storage).15

Users have found the HOME Injury Survey, a 

55-item tool that quantifies unintentional injury 

hazards in the indoor environment of homes 

with young children, to be reliable, valid, and reproducible16. Figure 4.17 illustrates categories of 

home injury hazards.

Falls

Bathrooms, stairs, windows, and outdoor play 

equipment should be evaluated to ensure that 

safety devices such as grab bars and nonslip surfaces are installed, especially for the 

elderly; that safety gates are used to block 
page 82 Housing-Related Health and Safety Hazard Assessment

Figure 4.17 Main Injury Hazards in the Home

Assess for the Presence of These Items

1. Safety latches and locks for cabinets.

2. Safety gates.

3. Door knob covers and door locks.

4. Anti-scald devices for faucets and showers.

5. Smoke detectors on every level of the home.

6. Window guards and safety netting.

7. Corner and edge bumpers.

8. Outlet covers and outlet plates.

9. Carbon monoxide (CO) alarms outside bedrooms.

10. Window blind cords secured.

11. Door stops and door holders.

12. Cordless phones make it easier to continuously watch young children.
page 83

stairs for children; that windows presenting 

fall hazards have permanent window guards 

affixed; and that outdoor play equipment is 

placed on an impact-absorbing surface. Stairs 

should be evaluated for structural defects and 

the presence of adequate railings on both 

sides. Cords that present trip hazards should 

be moved and secured. Throw rugs should be 

attached to the floor or used with non-slip pads 

to secure them. Also, check for trip hazards 

related to changes in elevation, such as with 

steps, ramps, or where there is a change in 

surface level. The visual examination should also 

check for adequate lighting over steps and other 

uneven surfaces.

Poisoning/ Storage of Household Chemicals 

The visual examination should examine how 

household chemicals are stored and whether 

or not they are within the reach of children. 

In homes with, or visited by, young children 

bathrooms and kitchens should be assessed for 

the presence of safety locks on cabinets that 

contain medicine and dangerous substances, 

such as cleaning supplies or biocides to control 

pests. These types of products should not be 

stored with food supplies. Flammable and volatile 

substances such as gasoline and paint thinner 

are best stored in a detached building such as 

a shed or garage. All pre-1978 homes should be 

inspected for deteriorated lead-based paint, lead 

dust, and soil-lead hazards. Home visitors can 

be easily trained to visually identify deteriorated 

paint and refer these potential hazards to trained 

inspectors or risk assessors. 

Fire and Burns 

Homes should be inspected for the existence of 

at least one smoke alarm on each floor, including 

the basement and outside each sleeping area. 

Smoke alarms should be mounted high on walls 

or ceilings and away from windows and doors. 

It is not recommended that smoke alarms be 

installed in kitchens since they are more likely 

to be disabled from this location. Hot water 

temperature should be measured using a 

thermometer to ensure that it does not exceed 

120°F and water heaters should be set to 120°F. 

Safety covers for electrical outlets should be 

used if young children reside in or frequently 

visit the home.

Choking

Home environments should be assessed for 

objects accessible to children that may result in 

a choking incident. This includes toys with small 

parts, coins and other small items that could be 

ingested by young children. Education should be 

provided related to choke hazards for children 

and the infirm elderly.

Drowning

Pools and hot tubs should be inspected for 

fencing on all sides to prevent drowning. Nonrigid pool covers can also be used to reduce 

the occurrence of drowning when pools are not 

in use. Uncovered rain barrels and five-gallon 

buckets used for cleaning are also a potential 

danger and should be used with caution when 

toddlers are around.

Suffocation and Strangulation

Sleep and play environments should be assessed 

for safety. The Consumer Product Safety 

Commission has published mandatory standards 

for cribs, including requirements for side height, 

slat spacing, and mattress fit. Co-sleeping (infants 

sleeping with adults) should be avoided. Toy boxes 

should be inspected to ensure that they have 

proper lid supports and window covering cords 

should be secured and out of reach of children. 

Plastic bags should be kept out of children’s reach.

Tip-Over Hazards

Furniture and appliances such as televisions that are 

not well secured represent tip-over hazards to young 

children in particular. Children can be subject to 

injuries from tip-overs, in particular crush and head 

injuries. Home inspectors should ensure that furniture 

and appliances are stable and not prone to tipping. 

Large appliances and furniture (e.g., bookcases) 

should be anchored to the wall and televisions should 

be on sturdy, low bases and should be pushed as far 

back on stands as possible. Remote controls, toys, and 

other items that might attract children should be kept 

off of TV stands or furniture that represent tip-over 

hazards.

Firearms

While questioning families about the presence 

of firearms may not be comfortable, a discussion 

about the presence of guns should be initiated 

Housing-Related Health and Safety Hazard Assessment
page 84

when possible. Guns should be removed from a 

child’s environment. When stored, firearms should 

be unloaded and ammunition locked up separately 

from guns. Trigger locks should also be used.

Structural Defects

The visual examination should include all 

elements of the structure of dwellings to ensure 

they are properly maintained to ensure they 

remain safe and stable. The dwelling should be 

assessed for signs of structural movement, such 

as cracks and/or bulges to external walls, open 

joints in brick, stone or block work, in external 

walls or chimney stacks. Also look for siding 

defects, such as loose, missing, or other insecure 

external finish to external walls, disrepair to 

lintels/sills, and poor roof conditions, such as 

sagging, distorted, or missing shingles, and 

loose missing or improperly fastened gutters/

downspouts. The goal is not to make healthy 

homes assessors experts on building structural 

issues, rather they should be able to identify 

possible problems that could be referred to 

those with more expertise on the topic.

Insulation and Temperature Regulation 

In many climates, poor temperature regulation 

can result in hazardous conditions, especially 

for vulnerable populations. Although an 

assessor may not encounter extreme conditions 

at the time of the assessment, information 

on the occupant’s thermal comfort can be 

obtained during the resident interview or 

by a combination of visual assessment and 

interview. The visual examination should check 

for adequate insulation (where possible), the 

adequacy of caulking and weather-stripping, the 

age and condition of the heating and/or cooling 

system, and holes or other voids in the building 

envelope that should be repaired. In many 

instances, ventilation from open windows may 

be limited or non-existent due to concerns with 

crime or noise (i.e., windows locked or barred 

shut).

Cleanliness and Clutter

Because house dust is the primary medium through 

which residents are exposed to toxins (e.g., lead, 

pesticides) and allergens (e.g., cockroach, dust 

mite) it is important that residents engage in 

regular and effective cleaning. Regular cleaning 

is also an important aspect of integrated pest 

management and is essential in food preparation 

areas for preventing bacterial contamination of 

food. Excess clutter can prevent effective cleaning, 

interfere with IPM implementation, and pose a fall 

hazard for occupants, especially seniors. Visual 

assessment instruments should include one or 

more items for the assessment of cleanliness and 

clutter and questionnaires often include a question 

on cleaning habits. A key consideration with this 

assessment is whether the residents are capable of 

maintaining cleanliness in the dwelling, or whether 

other characteristics (e.g., arrangement of furniture, 

condition of surfaces) interferes with cleaning. For 

example, the lack of smooth, cleanable surfaces in 

the kitchen can make cleaning difficult. Clutter may 

also pose trip or fall hazards and may block access 

to exits and entrances. 

Hoarding

Compulsive hoarding is a psychological 

condition characterized by the acquisition 

of, and failure to discard, a large number of 

possessions that appear to be useless or of 

limited value. Hoarding is defined as having the 

following three components: 1) the acquisition 

of and failure to discard a large number of 

possessions that may appear to be useless or of 

little values; 2) living spaces sufficiently cluttered 

so that the clutter precludes activities for which 

those spaces were intended; and 3) significant 

impairment in functioning or distress caused by 

the clutter.17

Hoarding represents an extreme type of clutter 

that may result in filth, infestations and serious 

maintenance problems. Hoarding is only a focus 

on the number of possessions, and can range 

from mild to life threatening. Squalor is filth and/or 

degradation from neglect. Commonly associated 

with hoarding are health and safety hazards 

(including building code violations). It is possible 

to have hoarding and squalor together but both 

conditions can also exist independently. Many 

hoarders have one or more other mental health 

conditions (e.g., depression, generalized anxiety, 

obsessive-compulsive disorder, social phobia, 

failure to process or organize information). 

Hoarding situations must be handled in a 

multidisciplinary manner. Healthy homes 

programs should address hoarding as part of 

a team that may include the sufferer, family 

members, the housing provider, local health 

departments, representatives of the judicial 

Housing-Related Health and Safety Hazard Assessment
Housing-Related Health and Safety Hazard Assessment page 85

system, and providers of therapeutic, social and 

clean-up services. Long-term case management 

and monitoring is needed. 

Prioritizing Visual Assessment 

Results

The results of the visual assessment should be 

presented as a prioritized list of items requiring 

repair or remediation. Priorities depend to some 

extent on the program’s focus but the level 

of health risk posed by the condition must be 

considered regardless of the focus. Hazards that 

might result in immediate harm or death must be 

corrected first. Although there is no universally 

accepted system of weighing each item for its likely 

health impact, two rating systems have been used. 

As mentioned previously, HUD’s Healthy Home 

Rating System uses an approach that prioritizes 

health hazards based on the likelihood of the 

hazard resulting in harm, and the extent of the 

harm should it occur. 

Healthy Homes programs have used a variety of 

methods for prioritizing the results of the visual 

Table 4.1 Priority List of Better Homes for Asthma (adapted from Seattle/King 

County Health Department)18

High priority items are indicated with an [A] and lower-priority items with [B] or [C].

Description

Vent clothes dryer to exterior using rigid metal ducting, not flexible plastic. [A]

Repair plumbing leaks [A]

Correct mold problems [A]

Clean evaporator pan under refrigerator [A]

Install range hoods that vent to exterior [A for gas; B for electric]

Repair dry floor drain traps if sewer gases detected [A]

Assure that at least one window in each room can open [A]

Remove basement, bath and kitchen wall to wall carpet [A]

Install smoke and carbon monoxide alarms [A]

Repair deteriorated bath and tub caulk [B or C]

Install pleated filter in forced-air heating system. [A]

In the crawl space, seal /cover soil with poly. [A]

Seal crawl space from house air. [A]

Assure adequate runoff from downspout away from house. [A: wet walls; B: other]

Caulk windows. [A]

Caulk wood siding vertical seams. [A]

Caulk door seams. [A]

Repair roof and chimney flashing if damaged or evidence of interior leaking is observed. [A]

Check furnace chimney draft and, if inadequate, check cleanout opening. [A]

Redirect flow from gutters to functioning downspout. [B]

Check return and supply ducts (only if in garage, crawl space, or attic) for leaks. [B]

Remove debris from the crawlspace, make rodent-proof. [B]

Wood-earth contact—assure 6 inch minimum gap. [C]

Repair or replace leaky chimney flue. [A]

Seal basement concrete if moisture probe indicates high moisture content. [C]
page 86

Figure 4.18 Prioritizing Interventions—Field Practices

Better Homes for Asthma Program in Seattle

prioritizes interventions based on interview data, 

visual assessments, environmental sampling, 

caregiver knowledge and practices, a child’s 

allergy test, and assessment of potential moisture 

problems.

Cincinnati Children’s Hospital’s Injury 

Prevention Program reviews options with parents 

who choose interventions based on a presentation 

of alternatives in rank order from the most 

passive and permanent to the least passive and 

non-durable (e.g., self-closing and locking stair 

gate bolted to a wall compared with a pressure 

mounted stair gate).

Healthy Homes Program in Baltimore prioritizes 

interventions in part by client-identified concerns 

and needs.

assessments. Usually this involves preparing an 

action plan in consultation with the residents and 

property owner. Table 4.1 provides an example 

of priority rankings from the Neighborhood 

House in Seattle’s “Better Homes for Asthma”

Demonstration project and Figure 4.18 show 

other examples from the field. HUD’s Public 

Housing Assessment System (PHAS) uses preestablished weighting of items on the physical 

assessment checklist and allows the assessor to 

assign severity scores based on specific criteria 

for some of the items. (see: www.hud.gov/offices/

reac/products/prodpass.cfm).

Environmental Sampling and 

Measurement Methods—General 

Considerations

Depending on the goals of your program, visual 

assessment can be used in conjunction with 

environmental testing, sometimes called “sampling 

and analysis,” and building performance testing (e.g., 

as conducted by Weatherization Assistance Programs). 

The purpose of environmental sampling is to determine 

levels of harmful substances and agents in air, soil, 

dust, water, or on surfaces or other media. Some 

contaminants may be odorless (such as radon or carbon 

monoxide) or not amenable to examination by the 

naked eye (such as lead or pesticide residues). The results 

are typically compared to either existing exposure 

limits or to levels in the outdoor air. Interpretation of 

sampling results may prove difficult since, with few 

exceptions such as lead and radon, environmental 

exposure standards for residential environments have 

not been established. Levels of allergens in settled dust 

such as dust mite and cockroach can be measured to 

characterize hazards in a program’s target housing, or 

collected pre- and post-intervention to determine if 

program efforts have produced desired changes.

Housing-Related Health and Safety Hazard Assessment

Information on levels of contaminants in a 

home can be obtained by collecting samples 

for subsequent analysis by a laboratory (e.g., 

lead wipes) or by using portable instruments 

(sometimes called “grab sampling” or “realtime analysis”) to provide instantaneous 

measurements during the home assessment (e.g, 

a CO meter). A sample can be collected during 

the initial visit or a sampler can be left in the 

home to be collected at a follow-up visit (e.g., a 

longer term air sample). In general, samples or 

measurements collected over a longer period 

of time (typically termed a “time-weighted 

average”) are more likely to provide an accurate 

indication of typical values than short-term, grab 

samples. The simplest real-time measurements 

include temperature and humidity; instruments 

are often also used to measure carbon monoxide 

concentrations or to determine if there are 

atypical levels of volatile organic compounds or 

particulates in the air.

Before deciding whether to collect environmental 

samples or measurements it is important to 

consider the following factors: (1) how the data 

will be used (e.g., will it inform mitigation decisions 

or is it suitable for assessing the effectiveness of 

interventions?); (2) whether there is a standard 

or guideline for the analyte that is suitable for 

the home environment; (3) the ease of sample 

collection; and (4) the cost. For example, if pets or 

pests are present in a home, it can be inferred that 

elevated levels of the associated allergens would 

be found in dust samples. Also, guidance from 

authoritative sources on mold/moisture issues 

generally discourages environmental sampling for 

mold because of difficulty interpreting the results 

and the fact that mold/moisture problems that are 

observed should be mitigated regardless of the 
page 87

an air sampling pump, which pulls air at a known 

flow rate through a filter or other collection media, 

which is then sent to a laboratory for analysis.

Each of these approaches has its strengths and 

weaknesses. For example, passive systems, if 

available, tend to be simple; they do not require 

a great deal of training and cost less (see Figure 

4.19). Active systems may have greater accuracy 

and precision and may achieve the lower 

detection limits that are especially important for 

the home environment. In all cases, approved 

sampling and analysis systems should be used. 

Costs. Costs associated with environmental 

testing include the purchase or rental of 

equipment and, for some devices, regular periodic 

calibration or servicing by the manufacturer; 

staff time to collect the sample; sampling media; 

and laboratory shipping and analysis. In order to 

contain costs, the question to be answered by 

the sampling should be articulated and various 

approved methods considered by asking the lab.

Prior consultation. If laboratory analysis is 

contemplated, it is essential that field personnel 

communicate with the laboratory before samples 

are sent. This will help determine laboratory 

capabilities, shipment procedures, and turnaround 

times. In addition, industrial hygienists may 

be helpful in designing field-based sampling 

efforts. A listing of board-certified industrial 

hygienists is available from the American Board 

of Industrial Hygiene, http://abih.org/members/

roster/rostersearch.cfm. Healthy Homes programs 

should assure that laboratory and field personnel 

are properly trained, licensed, and accredited.

Adapting air pollution and workplace sampling 

to the home environment. For many contaminants 

found in the home environment, scientifically 

based health exposure limits do not yet exist. 

Several options are available to overcome this 

deficiency. One approach is to compare indoor 

to outdoor levels. Another is to compare the 

indoor level to exposure limits established for the 

occupational setting, although these limits are 

typically set for healthy adults who are exposed 

over a typical eight-hour workday. Clearly, these 

may not be a valid comparison for housing 

occupants who may have longer-term exposures 

or be in poor health and may include children, the 

elderly, and other sensitive populations. A list of 

indoor exposure levels has been published by the 

Air Infiltration and Ventilation Centre (AIVC) in 

Housing-Related Health and Safety Hazard Assessment

Figure 4.19 Passive Diffusion 

Dosimeter

findings from environmental sampling.19,20

Once a program has made the decision to collect 

environmental samples or to take measurements 

the choice of sampling methods will depend on: 

(1) the type of media sampled; (2) how rapidly 

results are needed; (3) available expertise; and (4) 

cost. The HUD/CDC Healthy Housing Inspection 

Manual and the HUD/CDC Healthy Homes 

Reference Manual each contain a list of sampling 

methods that can be used in a healthy homes 

inspection. Lead-based paint testing must be 

done by licensed lead-based paint risk assessors 

or inspectors. In most states, lead dust testing 

may be performed by a lead sampling technician 

or risk assessor. Healthy homes programs that 

will be doing environmental sampling should 

determine what training, licensing, and other 

legal requirements apply for their jurisdictions. 

Environmental sampling and analytical methods 

for lead in the residential environment have been 

established by law and are detailed in the HUD 

Guidelines for the Evaluation and Control of 

Lead-Based Paint Hazards in Housing.

21 A brief 

review of sampling methods follows.

Passive versus active systems. In general, 

there are two types of environmental sampling: 

passive and active. Passive systems rely on 

the contaminant being adsorbed onto special 

collection media via diffusion. One example is 

formaldehyde, for which the sorbent is opened to 

the air for a measured period and then analyzed 

in a laboratory. Active systems typically require 
page 88

Table 4.2 Environmental Testing and 

Sampling Methods

Environmental Hazard Sampling Method

Lead dust Dust wipe

Cockroach allergens Dust vacuum/filter-

 type material

Carbon monoxide Direct-reading 

 instrument or 

 detector tube

Carbon dioxide Direct-reading 

 Instrument or 

 detector tube

Volatile Organic Passive dosimeter or 

Compounds canister/GC-MS

Cat allergens Dust vacuum/filter-

 type material

Dog allergens Dust vacuum/filter-

 type material

Dust mite allergens Dust vacuum/filter-

 type material

Mouse allergens Dust vacuum/filter-

 type material

Pesticide residues Wipe or vacuum

Mold sampling Air pump/filter

Nitrogen Dioxide Passive badge

Particulate matter Air

Formaldehyde Passive badge

Temperature: Digital sensor

Relative humidity: Digital sensor

Radon:

Short-term 2-7 day canister or 

 data logger

Long term 3-month canister or 

 data logger

Housing-Related Health and Safety Hazard Assessment

Europe22 and by the World Health Organization in 

2010 (see: http://www.euro.who.int/__data/assets/

pdf_file/0009/128169/e94535.pdf).

Seventy-nine percent of healthy homes programs 

(more than 50 surveyed) collected environmental 

samples as part of their healthy homes projects 

(Figure 4.20). Twenty-one percent of the healthy 

homes programs collected only one set of 

environmental samples in each home, while 65 

percent collected two sets of samples or more. A 

“set” means a group of samples collected at the 

same time. Examples of environmental testing 

and sampling methods are shown in Table 4.2.

Specific Testing Methods

Testing Ventilation Systems 

Testing ventilation systems can be a useful 

addition to the visual assessment described earlier 

in this chapter. Good ventilation can help to keep 

exposures to contaminants, odors, moisture, and 

other substances low. However, controlling the 

source of the contaminant is always the primary 

approach because ventilation cannot always be 

expected to do the job. If a contaminant exists in a 

home, its source should be investigated. A source 

reduction strategy should be implemented before 

a ventilation system is installed or otherwise 

improved. Ventilation systems generally fall 

into two categories: Local exhaust ventilation is 

designed to move a relatively small amount of 

air containing the contaminant at the point it is 

generated before it can enter the indoor air at 

large. Examples in the home include kitchen and 

bathroom exhausts, chimneys, clothes dryers, 

vented combustion appliances (furnaces, water 

heaters) and range hoods over gas ovens and 

ranges. 

General dilution ventilation moves larger volumes 

of air, and, as the name implies, operates by 

diluting contaminants with uncontaminated air. 

While some multi-family buildings in the U.S. have 

a planned fresh air supply, relatively few singlefamily dwellings do. Instead, outside air enters 

the home in an uncontrolled manner through 

movement of air through the building envelope 

or through open windows and doors (referred to 

as passive ventilation). In some homes, outside 

air is brought directly into the home through 

mechanical ventilation, with more sophisticated 

systems recovering the heat from indoor air 

before it is exhausted. As building envelopes 

Figure 4.20 Most Frequently 

Reported Samples Collected by 

Healthy Homes Programs

• Dust mite allergens (64 percent)

• Relative humidity (64 percent)

• Temperature (56 percent)

• Mold (52 percent) 

• Lead (50 percent)
page 89

testers, and blower door tests. Smoke tubes can 

be used to identify “back-drafting” of exhaust 

from combustion appliances (e.g., water heaters) 

that do not have closed exhaust systems. In 

most healthy homes inspections, ventilation 

problems are identified visually. However, for 

healthy homes programs that partner with 

weatherization programs, the blower door test 

and pressure diagnostics are options. During 

a blower door test, the house is placed under 

negative pressure using an exhaust fan sealed in 

a doorway or other large opening. This method 

determines breaches or leaks in the building 

envelope. It can help pinpoint the pathways 

that allow contaminants into the living space. 

By identifying where the holes or leaks are, they 

can be repaired more cost-effectively.

Moisture Measurement

In addition to the visual assessment methods 

described earlier in this chapter, moisture 

measurements can help identify places needing 

attention. Moisture meters measure water content 

in building materials through gauging changes 

in electrical resistance/capacitance (Figure 4.12). 

Two major types of moisture meters include one 

that gauges surface moisture by measuring the 

current between two electrodes. The second type 

has two pins that can be inserted into building 

materials to measure moisture content or water 

activity. Most moisture meters are calibrated to a 

specific type of wood at a particular temperature 

and are accompanied by charts that have 

adjustment factors for different types of wood and 

different temperatures. If the adjustments are not 

are tightened for energy conservation purposes 

and building leakage declines, it is important 

that a system for an adequate supply of fresh air 

be planned and installed. As a result of research 

demonstrating that passive ventilation was not 

sufficient to provide adequate air exchange rates, 

in 2009 the State of California revised its building 

code to require that newly constructed homes 

incorporate mechanical ventilation23.

Airflow patterns can be quite complex and flow 

in unexpected directions if properly designed 

entry and exhausts (“holes”) are not included 

(Figure 4.21). Air moves from higher to lower 

pressure areas, and warm air rises while cold air 

settles. The buoyancy of warm air rising creates 

a “stack effect” in the building, just like hot air 

flowing up through a chimney. In tall buildings, 

this can sometimes cause apartments on the 

lower floors to be cold while those on the 

upper floors are hot. These air flows also move 

contaminants such as environmental tobacco 

smoke between units of multi-unit buildings.

Regulating pressure differentials so that air 

moves as intended is essential for good building 

design. Failure to regulate these pressure 

differentials can have serious consequences. For 

example, if a new air exhaust system is added 

without balancing air pressure, air that would 

normally rise through a chimney or fireplace can 

actually reverse direction and enter the living 

area, introducing carbon monoxide and other 

contaminants to the home. 

Many tools are available to evaluate ventilation 

and airflow, including smoke tubes or bottles, 

flow hoods, pressure gauges duct air-tightness 

Housing-Related Health and Safety Hazard Assessment

Figure 4.21 Air Flow Exhaust and 

Entries

Figure 4.22 Infrared Thermograph of 

a Ceiling with a Hidden Water Leak

Note: The blue section reveals the location of the water leak.

Degrees
page 90

done properly, inspectors are likely to get false 

conclusions from the meter reading.

Another method of identifying moisture 

problems behind walls and other building 

cavities is thermography. Here, a special camera 

photographs infrared spectra. Because building 

components with higher water content are 

“cooler” than those without water, components 

with higher water content appear bluer than 

those with lower water content (Figure 4.22).

Relative humidity is the measure of the amount 

of water vapor in the air at a specific temperature 

compared with the maximum amount of water 

vapor that air could hold at that temperature. 

It is expressed as a percentage. Total humidity 

depends on the temperature since warm air holds 

more moisture than cold air. Dew point is the 

temperature at which air becomes saturated and 

condensation forms on cooler surfaces, which can 

in turn lead to mold problems. 

Mold Sampling 

Mold sampling is generally not recommended 

because a visual examination and odor 

detection are usually adequate to identify a 

mold problem. Testing procedures do exist 

to determine the species of mold present in a 

house, but most healthy homes programs and 

others involved in mold remediation have come 

to the conclusion that such speciation does not 

yield the kind of information needed to inform 

remediation.24,25 Similarly, measuring the mold 

spore concentrations in air is generally not 

recommended because results can vary widely 

and are difficult to interpret. 

Testing for Gases

Carbon monoxide (CO) and oxides of nitrogen 

(NOx) are odorless, colorless gases that can 

cause health problems. CO can be fatal if 

present in high concentrations. As byproducts 

of combustion, they can enter the living space 

if there is inadequate venting and/or improper 

indoor use of combustion appliances (e.g., gas 

ovens to heat homes). Inspectors should test both 

the fuel-burning device to determine whether it is 

producing high levels of CO and NOx, as well as 

the ambient room air. Two systems available for 

testing for CO and NOx are:

• Direct-reading, real-time carbon monoxide and 

oxides of nitrogen analyzers, which require 

periodic calibration from the manufacturer; 

and 

• Detector tubes, which involve pulling a small 

volume of air through a glass tube filled with 

a resin that changes color in proportion to the 

concentration of CO or NOx in the air. The 

length of stain is read on a scale on the tube. 

(Figure 4.23).

Additional details on measurement of combustion 

by-products in the home environment are 

available from the Building Performance Institute. 

Radon is an odorless, colorless radioactive 

gas that, next to smoking, is the leading 

cause of lung cancer in the United States. 

The two principal means of laboratory-based 

measurement for radon used by healthy homes 

practitioners are:

• Systems that employ activated charcoal 

canisters; or

• Alpha-tracking devices, such as those that 

contain film.

Ideally, measurements should be taken over 

a long period and under conditions in which 

outdoor air incursion is at its lowest (e.g., winter) 

although short term measurements (e.g., two-toseven days) are also useful. If a short-term test 

registers a radon level of 4 pCi/L (picocuries per 

liter of air) or more, a long-term test or a second 

short-term test should be conducted to verify an 

actual problem before deciding that mitigation 

is needed. If the long-term result or the average 

Housing-Related Health and Safety Hazard Assessment

Figure 4.23 Detector Tubes
page 91

of two short-term tests is 4 pCi/L or more, 

mitigation is recommended. Residents should 

be instructed not to move the radon test kits 

or devices. For valid test results, it is important 

that test devices be returned to the laboratory 

immediately after completing the test. 

Formaldehyde and Other Volatile Organic 

Compounds (VOCs) can be measured by healthy 

homes practitioners using passive dosimeters, 

which are analyzed in a laboratory. Detector tubes 

are also available for formaldehyde and individual 

VOCs. Interpretation of VOC results is difficult 

because residential standards have not been 

developed; there are many individual compounds 

with different toxicities and concentration can be 

very low. Standard and approved methods should 

be used whenever possible.

Testing for Allergens in Settled Dust 

Allergens in settled dust and the resulting 

resuspension into the air from normal foottraffic and from soft furniture and bedding are 

associated with asthma and other respiratory 

health problems. Estimates of sensitization 

and asthma exacerbation thresholds, based on 

concentrations of allergens in dust, have been 

developed from epidemiological studies. (Table 

4.3). Sampling for allergens in settled dust 

before and after a healthy home intervention 

has been used to estimate the effectiveness 

Housing-Related Health and Safety Hazard Assessment

of the intervention. The National Survey of 

Lead and Allergens in Housing showed that 

housing conditions are linked with allergen 

levels. Of the surveyed homes, 51.5 percent 

had at least six detectable allergens and 45.8 

percent had at least three allergens exceeding 

thresholds. Race, income, housing type, 

absence of children, and presence of smokers, 

pets, cockroaches, rodents, and mold/moisturerelated problems were independent predictors 

of high allergen burden.26

Most healthy homes programs use a single 

sampling method whereby a vacuum is fitted 

with a dust collection device. The dust is sent 

to a laboratory where it is sieved and analyzed 

using several differing analysis methods. 

One recent development is the MARIATM 

(Multiplex Array for Indoor Allergens) method 

which enables the rapid determination of 

multiple allergens from a smaller quantity of 

dust. This method may not provide results 

that are directly comparable to the common 

allergen-specific ELISA (enzyme-linked 

immunosorbent assay) analysis for some 

allergens, so healthy homes programs should 

work with their analytical laboratories to be 

sure that the same analytical method is used 

for dust samples collected before and after 

remediation. Research is underway to improve 

standardization of both field and laboratory 

methods. Personnel collecting these samples 

Table 4.3 Current Threshold Levels for Assessing Common Residential Hazards 

Allergen Asthma Symptom Threshold

 Dust mite allergen (Der f 1 and Der p 1) in the bedroom 10 μg/g (Platt-Mills et al., 1995)

 Cockroach allergen (Bla g 1 and Bla g 2) in the kitchen 8 Units/g (Eggleston and Arruda, 2001)

 Cat allergen (Fel d 1) in the bedroom 8 μg/g (Ingram et al,1995; Custovic et al., 1998) 

 Dog allergen (Can f 1) in the bedroom 10 μg/g (Ingram et al.,1995; Custovic et al., 1998) 

 Mouse allergen (Mus m 1) in the kitchen 1.6 μg/g23 (Phipatanakul et al., 2000)

(Note: Thresholds are subject to change and may not reflect actual risk. References: Custovic A, Chapman M. Risk levels 

for mite allergens. Are they meaningful? Allergy. 1998; 53(suppl 48): 71–76. Eggleston PA, Arruda LK. Ecology and 

elimination of cockroaches and allergens in the home. J Allergy Clin Immunol. 2001; 107(suppl 3): S422–S429. Ingram, 

J.M., Sporik, R., Rose, G., Honsinger, R., Chapman, M.D., Platts-Mills, T.A.E., 1995. Quantitative assessment of exposure 

to dog (Can f 1) and cat (Fel d 1) allergens: relationship to sensitization and asthma among children living in Los Alamos, 

New Mexico. J Allergy Clin Immunol. 96, 449–456. Phipatanakul W, Eggleston PA, Wright EC, Wood RA. Mouse 

allergen, part I: the prevalence of mouse allergen in inner-city homes. The National Cooperative Inner-City Asthma 

Study. J Allergy Clin Immunol. 2000; 106(6): 1070–1074. Platts-Mills, T.A., Sporik, R.B., Wheatley, L.M., Haymann, P.W., 

1995. Is there a dose response relationship between exposure to indoor allergens and symptoms of asthma? Journal of 

Allergy and Clinical Immunology 96, 435–440.)
page 92

need to be trained to collect dust samples 

using a standard protocol. Asthma symptom 

thresholds have been published and are useful 

in interpreting allergen sampling results, 

although the use of new standards and sampling 

and laboratory analytical methods may not 

permit easy comparison (Table 4.3). HUD has 

developed sampling guidelines for allergens 

in settled house dust: www.hud.gov/utilities/

intercept.cfm?/offices/lead/library/hhts/

DustSampleCollectionProtocol_v2_05.08.pdf).

Monitoring for Pests

Like other healthy housing issues, pests in 

housing and the methods of detecting and 

controlling them are often intertwined with 

other housing deficiencies, especially inadequate 

moisture control; deferred maintenance 

associated with structural defects that create 

entryways and harborage for pests; leaks; 

clogged drains and gutters; improperly graded 

soil around the house; and clutter. Holes and 

penetrations in the building envelope permit 

pests to enter the dwelling. Poor moisture control 

provides the necessary water for pests to flourish. 

Access to nutrients can often be prevented by 

ensuring proper storage of food, trash, and 

garbage, and cleaning of all food preparation 

surfaces, utensils, and other equipment. (See 

Figure 4.24 for links to additional information.) 

Resident complaints about pests are often the 

first indication of an infestation, and they should 

be encouraged to report evidence immediately 

so infestations do not spread. A trained pest 

management professional (PMP) will use this 

information to conduct a visual inspection that 

can identify the type of pest and its location(s) 

Housing-Related Health and Safety Hazard Assessment

in the dwelling. Fecal matter released by insects 

and rodents along common pathways around the 

perimeters of rooms provides relevant information. 

Insect fecal matter is typically spherical while 

fecal matter from rats or mice is usually elongated 

with one pointed end due to the presence of 

a sphincter. Other body parts, such as cast off 

exoskeletons or fur, may be visible. Of course, the 

most obvious visual evidence of the pest is the 

actual live or dead animal. 

Rub marks and burrows are also signs of pest 

activity. Exterior evidence may include ant 

mounds, burrows, and nests. A trained observer 

looks in food storage areas and trash and 

garbage disposal systems, such as trash chutes. 

Penetrations in walls, under kitchen sinks, in 

basements, and in other areas suggest that pest 

infestations may be present. Some practitioners 

have found that the use of a heat gun can drive 

cockroaches into the open where they can be 

observed easily. 

Monitoring with glue traps is also effective 

for cockroaches. Since cockroaches often do 

not emerge in daylight hours, monitoring with 

overnight traps may be more reliable than 

looking for the pests themselves (Figure 4.25). 

Cockroach glue traps are glue-covered strips of 

cardboard available in many shapes and styles. 

The two most basic types come in a triangle or 

flattened tube. If cockroaches are seen, they are 

likely to be found in cracks and crevices.

All visual survey systems attempt to identify 

potential harborage sites. Harborage simply 

means those areas where pests are able to take 

shelter (e.g., unused boxes in basements, clutter, 

brush and bushes near structures, and standing 

water containers). 

Figure 4.25 Cockroach Monitoring

Roach monitoring stations

Figure 4.24 Methods of Pest 

Detection

Methods of detecting pests are varied and 

described in detail in the CDC manual on 

integrated pest management: http://www.

cdc.gov/nceh/ehs/docs/IPM_Manual.pdf. 

The Healthy Housing Reference Manual 

also provides detailed guidance on how to 

identify the most common types of pests in 

different regions of the country. IPM training 

material can also be found at http://www.

stoppests.org
Housing-Related Health and Safety Hazard Assessment page 93

Cockroach baits and traps can be placed in 

corners, under refrigerators, and under sinks. If 

glue traps reveal an increase in pest prevalence, 

then quick action can help to avert a large 

infestation. Useful instructions on proper 

placement of sticky traps can be found at: 

healthyhomestraining.org/ipm/HUD_M2M.htm. 

The most common signs of rodent infestations 

are those that can be seen, such as feces, urine 

stains that can be detected with a UV flashlight, 

stored food that has been opened or shows 

gnaw marks, nests, burrows, and rub marks 

along walls and other linear surfaces.

Bed bug infestations are becoming increasingly 

common, especially in multifamily housing. Bed 

bugs cannot be controlled by common IPM 

techniques such as denying pests access to food 

and water since they do not need food or water 

for extensive periods. Their survival depends 

simply on a human host who can offer a blood 

meal every few months. Signs to look for when 

inspecting for bed bugs include dark spots (about 

this size: •), which are bed bug excrement that 

may bleed onto the fabric; tiny white eggs and 

eggshells (about 1mm); skins that nymphs shed 

as they grow larger; live bed bugs; and rusty 

or reddish stains on bed sheets or mattresses 

caused by bed bugs being crushed. See: epa.gov/

pesticides/controlling/bedbugs.html. 

Finally, a healthy housing inspection should 

explore information on previous use of 

pesticides, if known. Routine monthly spraying 

of pesticides may be an early indication of both 

pest infestation and exposure to pesticides. 

Routine spraying indicates an ineffective pest 

control strategy that does not follow IPM 

principles. Protective gear and tools for healthy 

homes inspectors investigating pest infestations 

are listed in Figure 4.26.

Sampling for Lead

Procedures for identifying lead-based paint and 

lead-based paint hazards are contained in the 

HUD Guidelines for the Evaluation and Control 

of Lead-Based Paint Hazards in Housing and 

regulated by EPA and many state governments. 

Dust-wipe sampling is performed by trained 

sampling technicians or lead-based paint 

inspectors or risk assessors. Measurements 

taken via x-ray fluorescence (XRF) or paint chip, 

soil, and water samples all require specialized 

training and licensing/certification. The extent 

of training and certification needed to perform 

these sampling techniques varies from state 

to state. Make sure your program adheres to 

state or EPA requirements. Laboratories that 

analyze paint, soil, and dust for lead must be 

EPA-recognized through the National Lead 

Laboratory Accreditation Program (NLLAP).

Figure 4.26 Healthy Homes Pest Inspection Gear

Inspectors should wear protective gear when 

investigating sites with potentially heavy pest 

infestations. EPA and CDC recommend the 

following tools and equipment:

• Building or floor plan to mark areas that need 

follow-up or regular ongoing inspections.

• UV flashlight for detecting urine stains that 

fluoresce under ultraviolet light.

• Standard flashlight.

• Knife or flat spatula for scraping narrow 

crevices where pests like to hide. If a spatula 

fits in a crack in concrete, baseboards, or 

wallboards; behind a kitchen or bathroom 

backsplash; or any other space 1/16” or greater, 

insects can use that space to enter a building.

• Hand lens or jeweler’s loupe magnifying glass 

for insect identification.

• Vial for collecting specimens.

• Pest identification guide book.

• Telescoping mirror (one that extends from 6” 

to 36” is perfect for seeing behind or under 

hard-to-reach places.

• Dust mask.

• Small portable HEPA vacuum.

• Hard hat.

• Protective eyewear.

• Small ladder.
page 94

of home energy retrofit measures. Typical 

cost-effective measures include air sealing and 

insulating the building shell, heating and cooling 

system tune-ups, repairs, or replacements, and 

duct sealing and insulation. In addition to the 

energy conservation measures, the auditor will 

recommend measures to improve the health and 

safety of the residents. Typical health and safety 

related measures include adding mechanical 

ventilation to kitchens and bathrooms to manage 

moisture and other indoor pollutants, installing 

vapor barriers on dirt-floored basements or 

crawl spaces, and installing smoke and CO 

detectors. The successful energy audit results in 

a work order of measures that, when installed, 

will reduce energy consumption and potentially 

improve the health of occupants.

Energy Audits 

An effective programmatic strategy that provides 

additional benefit to program clients is to 

integrate a home energy audit with the healthy 

homes assessment. A home energy audit, as 

conducted by a Department of Energy (DOE)-

funded Weatherization Assistance Program, 

includes a comprehensive assessment of the 

current condition of a home followed by a 

detailed evaluation of the energy conservation 

measures that can improve the building’s 

performance (see: http://waptac.org/TechnicalTools/Energy-Audits.aspx). The first step is a 

comprehensive assessment that includes visual 

and diagnostic assessments of the whole home 

as a system, including the building shell, heating 

and cooling systems, and appliances. Combustion 

appliances are tested for safety and efficiency, 

existing insulation levels are determined, air 

leakage is measured, electrical appliances are 

metered, moisture and other health hazards are 

evaluated, and the residents are interviewed 

about energy usage, trouble areas in the home, 

and health issues that may be connected to the 

indoor environment (Figure 4.27 shows a blower 

door test to estimate air leakage).

The data collected during the comprehensive 

assessment, or site audit, is then entered into an 

approved energy audit software tool, such as the 

DOEs Weatherization Assistant. Based on the 

local climate, energy rates, the costs of materials 

and labor, and the current condition of the home, 

the software evaluates the cost-effectiveness 

Housing-Related Health and Safety Hazard Assessment

Figure 4.27 Blower Door
page 95

Chapter 4 References*

1

 U.S. Department of Housing and Urban 

Development. 2007. An Evaluation of HUD’s 

Healthy Homes Initiative: Current Findings and 

Outcomes.

2

 Centers for Disease Control and Prevention 

and U.S. Department of Housing and Urban 

Development. 2006. Healthy Housing Inspection 

Manual. Atlanta: U.S. Department of Health and 

Human Services. Available: http://www.cdc.gov/

nceh/publications/books/inspectionmanual/.

3

 Wilson. J., Breysse, P., Dixon, S., Jacobs, D.E., 

Chew, G.L., Dearborn, D., Krieger, J., Spanier, A., 

Sandel, M., and Adamkiewicz, A. 2010. Housing 

characteristics and allergens associated with 

childhood asthma morbidity: A pooled analysis of 

nine studies. Environmental Research. 110:189–198.

4

 U.S. Department of Housing and Urban 

Development. 2006. Healthy Homes Issues: 

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Notes

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