Guide to Arc Re-Entry
Version 1.1

June 2020

Arc Re-Entry Guide v1.1
Summary
Arc Re-Entry is a set of tools to support a safe, confident return to work, school, andplay. Re-Entry builds on Arc’s long-standing performance categories with newcapabilities to assess facility management, evaluate occupant experience, andmeasure indoor quality. With Arc Re-Entry:
1) Any project can collect, manage, and score infectious disease-related information
about facility management, occupant experience, and indoor air quality.
2) Arc Essential subscribers can analyze performance and create customized reports for
projects and portfolios.
Consistent with Arc’s broader mission, these tools can be used to create feedback
loops between management intent and real world outcomes. As always, Arc will use
this information to recognize leadership and celebrate people and organizationsdelivering superior real world performance.
Arc Re-Entry:● Supports the iterative assessment of facility management and occupant
experience -- ​not the health of individual occupants or infection risk.
● Aggregates and interprets information reported by facility managers andoccupants -- ​the information provided is only as useful as the quality of theincoming data and the underlying scientific literature used to interpret it​.
● Data are subject to automated quality tests -- ​not document review.
Recommended citation:​ Pyke, C.R. (2020) Guide to Arc Re-Entry v1.1. ArcSkoru, LLC, Washington, DC,
24 pages. URL: ​https://www.arcskoru.com/sites/default/files/Arc%20Guide%20to%20Re-Entry.pdf

2

Contents
Summary

2

Quick Start

4

Introduction

5

From Performance to Re-Entry

6

Re-Entry Comprehensiveness Score

9

Facility Management

10

Referencing LEED, WELL, and RESET

12

Sample Facility Management Response

13

Examples of Relevant Public Health Authorities

14

Facility Management Comprehensiveness Score

15

Occupant Observations

16

Sample Occupant Observation Responses

17

Occupant Observations Comprehensiveness Score

18

Indoor Air Quality

19

Sample IAQ Measurements

20

IAQ Comprehensiveness Score

21

Tips for Entering Spatial Data Coverage

22

Tips for Entering Temporal Data Coverage

23

Analysis26

Conclusion

28

Contact

28

About Arc28

3

Quick Start
Getting started with ​Arc Re-Entry​ is easy:
1. Login to Arc​, access an existing project or create a new one. Users must havea LEED Online or USGBC.org site user account. New users can ​create one forfree​.
2. After logging in, select a project and find the Leadership tab on the left side.
Select the Re-Entry category. The tab provides three options:○

Send Facility Manager survey○

Send Occupant Observation survey○

Add IAQ data

3. After sending surveys or adding data, you can review information about eachcategory in the Meters & Survey section. Each component has a Data, Details,
and Documentation tab. The Details tabs provide a summary of responses,
and charts to view performance over time.
If you need support, please reach out to the ​Arc team​ for help.

4

Introduction
The COVID-19 pandemic has had a sweeping impact on the global property industry.
Many authorities and academic researchers predicted a global pandemic anddescribed its potential consequences. However, it remained difficult to fully envision thescope of its impact on our everyday lives. It has changed so many aspects of how welive, work, and play. After months of lockdowns and quarantine, many communities areready to try to establish a new normal. This means returning to workplaces, schools, andplaces of recreation, public assembly, and worship.
We have learned a lot about how to keep ourselves safe during this re-entry, enough toknow that it will require a thoughtful, coordinated, and sustained effort. Short of a
vaccine, there is no magic bullet or single technology that will keep everyone safe.
Rather, we must create layered “defense in depth” to break the chain of infection. Thismeans keeping people separated, cleaning and sanitizing surfaces and spaces,
circulating and filtering air, and much more.
The good news is that we only need one break in the chain of infection to stop the
spread of disease. The bad news is that we need to create those breaks all the time,
everywhere. This is a challenge of professionals who design, build, and operate our built
environment. We are very good at creating exceptional projects that, at times, deliver
exceptional performance. However, we are not so good at delivering consistent
performance everywhere, all the time. This reflects the reality of managing buildings
and places. These are complex engineered systems, often unique in design, andsubject to all manner of operating conditions and occupant behavior.
While we cannot expect to be perfect, we can create systems to provide situationalawareness, offer transparency for stakeholders, and use information to improve
performance over time. This is our aspiration for Arc Re-Entry: a set of tools that help
facility and portfolio managers organize and communicate their infection control plans
and learn from occupant observations and measured indoor air quality. We envisionthat these tools will be used repeatedly to improve performance over time as we learn
more about what works to control the spread of infectious disease.
Arc Re-Entry provides tools for a marathon, not a sprint. To that end, we have worked toget started quickly with simple, practical features that we believe can provide value
over time. We are also committed to improving these tools in the months ahead tomeet this important moment and help us safely and confidently re-enter the places
where we live, work, and play.
5

From Performance to Re-Entry
Arc measures and scores the operational performance of spaces, buildings and places.
Arc scores distinguish leaders and help make real world performance measurement aubiquitous part of green building practice.
The ​Arc Performance Score​ provides a weighted combination of information in fivecategories, including:
●
●
●
●
●

Energy and Emissions
Water
Waste
Transportation
Human Experience

The Arc Performance Score powers ​LEED for Operations and Maintenance v4.1​ and
LEED Recertification​.
The ​Arc​ ​Human Experience ​category collects and scores information on two equallyweighted sub-categories:●●

Perceived occupant satisfaction
Measured indoor air quality, including CO2 and TVOC

Arc Re-Entry ​expands andadapts tools and metrics in
Arc to support the
management of infectious
disease transmission1. Arc
Re-Entry can complement
existing building rating
systems or be used as astand-alone tool.

Arc Re-Entry is focused on the management of infectious disease, specifically COVID-19.
Management recommendation would be significantly different for other aspects of health andwell-being. Relevant resources for other issues include the ​International WELL Building Institute​,
the ​Green Health Partnership​, and peer reviewed literature (e.g., ​Worden et al. 2020​).
1

6

Figure 1. I​ llustration of Arc Re-Entry support components, including data collection for facility management
policies and procedures, occupant observations, and measured indoor air quality.

Figure 2. A
​ rc Re-Entry can provide a starting point for health and green building rating systems, including
the WELL Health-Safety Rating and LEED v4.1 O+M.

Arc Re-Entry leverages existing
capabilities, including Arc’s
long-standing occupant satisfaction
survey and requirements for indoor
air quality measurement. These aresupplemented by two new surveys
and an expanded set of indoor air
quality metrics.
Additionally, Arc Re-Entry allows
managers to document and shareconnections with relevant publichealth authorities. This makes it
easier to explain why facility
managers have selected a given
set of infection control strategies.
Figure 3. A
​ rc Re-Entry data are entered in a new category under the Meters & Surveys tab.

7

In turn, Arc Re-Entry helps managers evaluate how occupants experience their
management strategies and how they may be reflected in measured indoor air quality.
This provides the basis for repeatable feedback loops between management intent
and measured outcomes.
New components introduced with Arc Re-Entry include:●

New facility management survey:​ The new facility manager survey requests
information about infection control policies and procedures and alignment with
relevant authorities (e.g., the World Health Organization, etc.).

●

New surveys for occupant observations: ​The new occupant observation surveys
include long-standing questions about occupant satisfaction, as well as newopportunities to share experiences with disease control-related features, such as
signage or access to disinfecting products.

●

New indoor air quality metrics: ​The new indoor air quality metrics expand on
Arc’s existing set of measurements and change interpretations to align withdisease control objectives. This means that CO2 and TVOC are found in both thelong-standing Human Experience category, as well as Re-Entry. However, themetrics have changed from concentrations of pollutants to the fraction of time
above a threshold. Additionally, the new section requests information about
relative humidity and particulate matter; aspects of air quality linked to diseasetransmission or susceptibility. All of these IAQ factors can be measured with either
portable instruments or sensor networks (e.g., ​Arc partners​ ​arbnco​ and ​QLEAR​).

All together, the new Re-Entry elements include 120 variables, including simple binary
responses, measurements, andsupporting documentation.
Information about each variable isavailable through ​Arc Re-Entry Meters
spreadsheet​.
Figure 4. A
​ rc Re-Entry supports the repeatedevaluation of infection control strategies. The
bold elements are explicitly addressed in thetool. The gray elements, Implementation andAnalysis, are taken outside of the tool.

8

Iterative Analysis
Arc Re-Entry is not a “one time” assessment. Arc Re-Entry is designed to be an iterativeevaluation of the comprehensiveness of infection control practices. It is designed toprovide transparency about management intent and support a comparison between
intentions and occupant experiences and measured outcomes. Fundamentally, thepower of the tool is in its repeated use. This means that it does not have a clearly
defined stopping or end-point. Rather, it should be used as long as it is needed to
improve management and build confidence for re-entry and on-going operations.

Re-Entry Comprehensiveness Score
Arc uses scores to interpret and integrate performance measurements​. ​Arc scores forenergy, water, and waste are benchmarked using a Reference Set. Arc scores fortransportation and human experience are based on mathematical functions. Neither ofthese approaches is appropriate to interpret re-entry-related information. Benchmarks
do not exist, and research to establish quantitative guidelines is still preliminary and, insome cases, conflicting. However, there is still a need to aggregate and interpret
information for facility managers and stakeholders. Consequently, Arc calculates a
Re-Entry Comprehensiveness Score (“Comp Score”).
The Comp Score is a 0 to 100% measure of the fraction of positive responses comparedto the total number of potential positive responses. The Comp Score is average of threecomponents: facility management, occupant observations, and indoor air quality. The
Comp Score should be interpreted as a simple indicator of the number of self-reported
actions implemented by the facility and scope of occupant or measured indoor quality
data describing conditions in a facility:●

Comp Score = 0: ​The facility reports no disease control practices andprocedures, occupants uniformly observe no disease control features, and noindoor air quality data are collected.

●

Comp Score = 100: ​The facility reports on all requested disease control practices
and procedures. The facility managers provide supporting documentation foreach element. Occupants uniformly observe disease control features. Indoor air
quality information is consistently collected throughout the facility.

Comp Scores between 0 and 100 indicate a simple proportion of potential affirmative
responses. There is no weighting beyond the equal proportions assigned to facility
management, occupant observations, and indoor air quality.

9In some cases, a response may not be applicable to a given facility. When a user
selects “not applicable”, the question is removed from both the numerator and thedenominator of the Comp Score equation. For example, a question about increasing
outdoor air supply might be not applicable for an open air venue. The absence of this
response does not “count against” the Comp Score.
Note: There is no way for Arc to independently verify the applicability of responses atthis time, and users should consider this when evaluating Comp Scores. Third-parties,
including the ​International WELL Building Institute​ and ​RESET​ may provide third-party
verification, such as on-site or data audits.
It is also important to note that Comp Scores are ​not a​ direct indicator of health or therisk of disease transmission. They are exactly what the name implies, an indicator of therelative comprehensiveness of management practices, occupant observations, andindoor air quality measurements.
Over time, it may be possible to use Comp Scores in research to evaluate theeffectiveness of different combinations of facility management to disease transmission.
However, this will necessarily be a retrospective analysis, possible only after re-entry hastaken place (e.g., does a higher Comp Score result in a lower risk of infection). It is notpossible to conduct this type of analysis until people have returned to different types ofspaces, and we have a distribution of responses (i.e., some have or have not gottensick). Until then, we can attempt to consistently implement Best Practices and measure
results.

Facility Management
Facility managers cannot stop the spread of infectious disease on their own. They doplay an important role in creating conditions that may reduce the rate or likelihood of
disease transmission. They can use management interventions to break the chain of
infection. This means limiting the introduction of virus-carrying occupants, reducing the
likelihood of spread through the air and on surfaces, and facilitating the use of barriers
and personal protective equipment to prevent exposure.

10Arc Re-Entry uses a survey to ask facility managers about:
1. Infection control policies and procedures.
2. Authorities used to inform or align the facility’s policies and procedures.
3. Specific elements included in the facility’s policies and procedures.
Each element includes a yes or no question and the opportunity to provide supporting
information as a hyperlink or file. The facility managers survey asks facility managers to
identify a number of specific strategies recommended by some authorities, including:●

Infection control policy or procedure:​ This is a written plan applicable to thefacility guiding effort to reduce the spread of infectious disease (e.g., the ​Hines
Return to Occupancy Plan​ or the ​BXP Health Security Plan​).

●Alignment with public health authorities: ​This question documents references oralignment with published guidance from government, academic, or non-profit
sources, such as U.S. Centers for Disease Control ​Interim Guidance for Businesses
and Employers Responding to Coronavirus Disease 2019​, ASHRAE ​Guidance for
Building Operations during the COVID-19 Pandemic​, BOMA ​Getting Back to
Work: Preparing Buildings for Re-Entry​, USGBC ​LEED Safety First: Re-Enter Your
Workspace Pilot Credit​, or ​IWBI’s WELL Health-Safety Rating​. Alignment isinterpreted as the intent for building management to substantially reflectmaterial aspects of the referenced authority.

●

Communications and signage:​ This question addresses signage and othercommunications intended to reduce disease transmission, such as advice
regarding hand washing or social distancing.

●

Cleaning and disinfection: ​This question addresses action to clean and disinfectspaces to reduce disease transmission, such as following​ ​LEED ​Safety First: Clean
and Disinfect Your Space​ guidance.

●

Occupant screening: ​This question addresses policies, procedures, or practices
intended to prevent disease carrying people from entering the facility. This may
take the form of health checks, temperature screening, or other measures, suchas recommendations in the U.S. Centers for Disease Control ​COVID-19 Employer
Information for Office Buildings​.

●

Paid sick leave:​ This question addresses potential incentives or disincentives forfacility management staff and contractors to work while sick.
11

Paid sick leave has been shown to reduce the likelihood of working while sick
and, in turn, spreading disease (see ​Castrucci and Auerbach (2002) in Health
Affairs​)​.
●Social distancing: ​This question addresses interventions to promote social
distancing, including physical barriers, seating, workstation design, and otherstrategies. Relevant guidance varies by facility type, such as the United Kingdom
Department of Digital, Culture, Media, and Sport, ​Guidance for providers of
outdoor facilities on the phased return of sport and recreation in England​ (June2020).

●

Ventilation and outdoor air supply: ​Some authorities have recommended
increasing ventilation rates and the supply of outdoor air. Strategies to increase
outdoor air supply vary, and they could be interpreted as increasing daily supply
through 24/7 operations or increasing average air flow.
Some facilities may also increase fresh air supply by encouraging the use ofoperable windows. If selected, supporting documentation should explain
specific strategies applied to this facility. Relevant research includes findings suchas ​Li et al. (2020)​ and guidance such as ASHRAE’s ​Position Document on
Infectious Aerosols​ and the R​ ESET standard​ (e.g., requirements for real time
tracking).

●

Air filtration:​ Some authorities have recommended enhancing HVAC filtration toremove smaller particles. Under some circumstances, this may reduce diseasetransmission. Guidance varies for the type and level of filtration recommended. If
selected, supporting documentation should explain the type of filtration used by
the facility and relative contextual information about HVAC design or operations.
Relevant research includes ​Bolashikov and Melikov (2009)​ and guidance
includes CIBSE ​Guidance on Ventilation during COVID-19​ and the ​National Air
Filtration Association​. Projects may consider ​RESET​ Core & Shell or Commercial
Interior guidance for the measurement and management of indoor and outdoor
airborne particulates.

●

Elevator operations: ​Some authorities have identified elevators as a potential
high risk area. Consequently, they have provided guidance for rider density,
waiting, and cleaning. Relevant research includes ​Kandel et al (2014)​ and
COVID-19 Precautions for Multi-unit Residential Buildings (2020)​ published by the
Canadian National Collaborating Centre for Environmental Health.

12●Potable water systems: ​Some authorities have emphasized the need to address
waterborne illnesses associated with stagnant water during re-entry of facilities
after unoccupied periods (e.g., Legionella). This potential scope of this problem
reflects facility-specific operating conditions and mechanical system design.
If selected, documentation should describe specific practices in the context offacility systems or circumstances. Relevant guidance includes U.S. Centers for
Disease Control ​Guidance for Reopening Buildings After Prolonged Shutdown or
Reduced Operation​, the Washington State Department of Health ​COVID-19
Guidance for Legionella and Building Water System Closures​, and the LEED
Safety First Pilot Credit: Building Water System Recommissioning​.

Referencing LEED, WELL, and RESET
Facility and venue managers may elect to use elements of the LEED or WELL rating
systems to inform their policies and procedures. They can reference rating systems orindividual credits as authorities. This reflects that these credits are based on a specificinterpretation of underlying research and guidance. This makes them practical tools
to guide facility management. Examples of relevant authorities include:●

U.S. Green Building Council: ​LEED credits, including S​ afety First: Re-Enter Your
Workspace​ and ​Safety First: Cleaning and Disinfecting Your Space●International WELL Building Institute: ​Strategies referenced in the forthcoming
WELL Health-Safety Rating●

RESET:​ Strategies related to indoor and outdoor air quality measurement andmanagement in the ​RESET Air Standard 2.0​.

These and other rating systems are providing timely, best practice-based guidance
for facility managers and occupants.

Sample Facility Management Response
A facility management might respond to the survey with the following:●

Does the facility have an infection control ​policy or procedure​?
○ Yes, file upload: 123_Main_St_Infection_Control_Plan_Section2.pdf

13●Is the policy or procedure aligned with one or more ​authorities​?
○ Yes, file uploads: U.S. Centers for Disease Control Guidelines, LEED ​Safety
First: Re-Enter Your Workspace Pilot Credit●

Does the policy or procedures include ​specific strategies​ for:○

Disease control ​communication and signage■ Yes, file upload: 23_Main_St_signage_photo.jpg○

Clean and disinfection ​to address disease transmission■ Yes, hyperlink: LEED ​Safety First: Clean and Disinfect Your Space○

Occupant screening■ Yes, file upload: 123_Main_St_occupant_screening_policy.pdf○

Paid sick leave ​for staff and contractors■ Yes, file upload: 123_Main_St_employee_policy.pdf○

Social distancing (​e.g., floor markers, barriers)?
■ Yes, file upload: 123_Main_St_Infection_Control_Plan_Section1.pdf○

Outdoor air supply■ Yes, file upload: 123_Main_St_Infection_Control_Plan_Section2.pdf○

Ventilation rates■ Yes, file upload: 123_Main_St_Infection_Control_Plan_Section3.pdf○

HVAC filtration■ Yes, file upload: 123_Main_St_Infection_Control_Plan_Section4.pdf○

Elevator management​ (e.g., limiting occupancy, targeted cleaning)■ Yes, file upload: 123_Main_St_Infection_Control_Plan_Section5.pdf○

Potable water management systems ​to reduce waterborne diseasetransmission, such as legionella?
■ Yes, file upload: 123_Main_St_Infection_Control_Plan_Section6.pdf

14

Examples of Relevant Public Health Authorities
Facility managers may be required or elect to align their infection control practices
with any number of authorities. This may include government agencies, academic
institutions, or non-governmental organizations. At this time, the specific combinationof applicable authorities is likely to vary by location, type of facility, and special
designations (e.g., essential vs. non-essential activities). This means that Arc cannot
recommend a specific set of authorities for any given facility. It will maintain examples
of authorities, and, when possible, it will share lists of authorities reported by Re-Entry
users.
Examples of authorities that may be referenced by facility managers include:●

5 Ways to Optimize Buildings for COVID-19 Prevention (Center for Active
Design) [​Link​]●

COVID-19 Disinfectant List (US Environmental Protection Agency) [​Link​]●

Position Paper on Airborne Infectious Disease (ASHRAE) [​Link​]●

Interim Guidance for Businesses and Employers to Plan and Respond to
Coronavirus Disease 2019 (U.S. Centers for Disease Control) [​Link​]●

Getting your workplace ready for COVID-19 (World Health Organization) [​Link​]●

Coronavirus Resource Center (BOMA International) [​Link​]●

Coronavirus Resources (BOMA Canada) [​Link​]●

REHVA COVID-19 guidance document, April 3, 2020 (Federal of European
Heating Ventilation and Air Conditioning Associations) [​Link​]●

Coronavirus (COVID-19) Advice (CIBSE) [​Link​]

Note: ​Guidance is under development from many sources, including academic
institutions, trade associations, and government. At the moment, these resources may
be incomplete and, at times, contradictory. These references will necessarily evolve
quickly in the month ahead.

Arc can deliver these surveys and track responses within a specified time period. Users
may select the interval that surveys are repeated. The default recommendation ismonthly or upon a significant change in operations​.

15

These new meters are available as API end-points for Arc partners. Review the ​Arc
Integration Guide​ for more information.

Facility Management Comprehensiveness Score
Arc will generate a Facility Management Comprehensiveness Score (“Comp Score”).
The Comp Score will reflect a 0 to 100% measure of the fraction of positive responses
compared to the total number of potential positive responses.
Facility Management component has 28 data elements, including boolean responses(i.e., yes, no) and opportunities to provide a supporting link or file.
A Facility Management Comp Score of 100% indicates that a facility manager provided
a “yes” answer for each question, along with a supporting link or file. Multiple file
uploads are allowed, but they do not increase the Comp Score.
By default, the Facility Management Comp Score is based on the most recent responseto the Facility Management Survey. The most recent response supersedes all previous
responses for the purposes of the Comp Score. Arc maintains a record of previous
responses to each applicable question.
In contrast to other components, responses to the Facility Management Survey are
considered valid for an indefinite period of time (i.e., no time limit or moving window isapplied to these data).

Table 1. C
​ omparison of the existing Arc survey with the Re-Entry Facility Manager Survey.
Existing Arc Facility
Management Survey
None

Re-Entry Facility
Manager Survey
Operating plans, policies, and procedures
Alignment with public health authorities
Plan or policies includes strategies for:○ Occupant communication and signage○ Cleaning and disinfection○ Occupant screening○ Social distancing○ HVAC management○ Elevator management○ Potable water management16

Occupant Observations
Arc has long-standing tools to understand occupant satisfaction. This includes anemail-based survey asking occupants about their experience. The survey dynamically
expands to ask for more information about reasons for satisfaction or dissatisfaction. This
simple occupant satisfaction instrument provides the foundation for an expanded set ofoccupant observations to support re-entry.
The goal is to support an iterative feedback loop between the intentions of facility
management and the experience of occupants. To this end, occupant observations
become a source of “ground truth” to confirm expectations or identify needs for
management action.
New re-entry elements include:●●●●

Observations about the presence of disease control signage
Observations about occupant screening, such as temperature checks
Perceived access to disinfecting products
Perception of social distance

Users are asked to evaluate each on a 5-point Likert scale:
●
●
●
●
●

Never
RarelySometimes
Usually
AlwaysEach element is associated with a free text box which provides opportunities to suggest
opportunities for improvement if the response is less than “always”.
Users can select one of three types of surveys to fit their situation:●●●

Base building only
Tenant space only
Whole building17This selection changes the introduction to the survey to request observations from theselected scope. Each option asks the respondent to reflect on a different area, such as
only common areas (base building) or their organization’s workspace (tenant space).
The selected survey can be targeted at specific groups, including:●●●

Facility management team or crew
Tenants or other habitual occupants
Visitors

Information about scope and groups is stored with responses to support follow up
analysis. Individual survey responses are anonymous with no identifiable information(i.e., an Arc user can see the scope and group, but not the identity of individuals).
Arc will deliver these occupant observation surveys and track responses within a
specified time period. Users may select the interval that surveys are repeated. The
default recommendation is ​weekly.​ Arc can also provide project-specific links that canbe distributed through other email or social media platforms.
The occupant survey end-points can also be directly populated by Arc’s integration
partners during the ​Arc API​.

Sample Occupant Observation Responses
The project manager makes two selections to control the framing and distribution of theoccupant survey. First, the manager selects the scope of the response (base building,tenant space, or whole building). Second, the manager selects the group (facility
management team/crew, tenants/vendors, or visitors).
An occupant might respond to the survey with (bold, highlighted items selected fromthe lists):
1. Occupant satisfaction
a. Extremely dissatisfied, very unsatisfied, unsatisfied, neither satisfied nor
dissatisfied, satisfied, ​very satisfied​, extremely satisfied
b. If satisfied, select the options that significant enhance your satisfaction:
thermal comfort​, cleanliness, views, sound, light, ​daylight​, ​air quality​,
privacy

18

2.

3.
4.
5.
6.

c. If dissatisfied, select the options that significant reduce your satisfaction:
dirty, smelly, stuffy, acoustics, hot, cold, dark, glare, privacy, humid, drafty,
bright, views, soundObservations about the presence of disease control signage
a. Select never, rarely, sometimes, ​usually​, always■ If not always, where is disease control signage missing?
● 7th floor kitchen
Observations about occupant screening, such as temperature checks
a. Select never, rarely, sometimes, usually, ​always
Do you have access to handwashing and disinfection?
a. Select never, rarely, sometimes, usually, ​always
Does the facility support social distancing?
a. Select never, rarely, ​sometimes​, usually, always
Do people maintain social distance?
a. Select never, rarely, sometimes, usually, always■ If not always, where is social distance not maintained?
a. Elevator lobby

Occupant Observations Comprehensiveness Score
Arc will generate an Occupant Observations Comprehensiveness Score (“CompScore”). The Comp Score will reflect a 0 to 100% measure of the fraction of positive
responses compared to the total number of responses.
For Facility Management, this means that there are six scored data elements(questions), each with a maximum value of 4 on a 5-point 0-to-4 scale. This means thatthe most comprehensive possible is an average of “always” (a value of 4) for all six
items -- a total potential value of 28. As a default, survey responses are aggregatedover a rolling 31-day window and compared to this maximum value on a scale of 0 to
100%.
This means that a facility with uniformly positive responses for all six indicators will receive
a score of 100% for a 30 day period. Data older than 30 days do not contribute to the
Occupant Observations Comp Score.
Note: The occupant observation survey also contains a seventh question, “Do you feel
protected from infectious disease in this facility?”. Responses to this high level question
can inform management. However, they are not directly related tocomprehensiveness, and they are not scored.

19

Table 2. C
​ omparison of the existing Arc occupant survey with the Re-entry occupant observation survey.
Existing Arc
Occupant Survey

Re-Entry
Occupant Survey

Occupant satisfaction plus:● If satisfied, source of satisfaction● If dissatisfied, source of dissatisfaction

Existing Arc occupant survey plus additional criteria:
Disease control signage● Present in the common areas● Present in my workspace
Presence of occupant screening● Present in the common areas● Present in my workspace
Access to handwashing and disinfection● Access in common areas● Access in my workspace

Indoor Air Quality
Measurements of indoor air quality provide proxy measures for factors believed to be
associated with disease transmission. It is important to note that none of themeasurements identified below provide direct information about infectious agents.
Rather, they describe proxies for conditions identified by scientific literature.
Measurements and interpretations include:●

Relative humidity: ​Relative humidity between approximately 40 and 60% has
been correlated with reduced disease transmission. Recent reviews such as
Lowen and Steel (2014)​ and ​Marr et al. (2019)​ summarize the literature.

●CO​2​ concentration:​ High indoor CO​2​ concentrations indicate inadequate
ventilation or crowding. Building standards (e.g., ASHRAE 62, EN 16798-1) haveconsistently sought to encourage greater ventilation to dilute indoor pollutants
and pathogens. High CO​2​ concentration levels have also been correlated with
reduced cognitive performance and alertness. Recent reviews such as ​Azuma etal. (2018)​ summarize the literature.

20●

TVOC concentration: ​TVOC concentrations are not directly related to diseasetransmission. They are included here, because they may provide information
about excessive applications of cleaning products and/or inadequate
ventilation. Reviews by the ​US Environmental Protection Agency​ and ​Lawrence
Berkeley National Laboratory​ provide more information.

●

Particulate matter concentration: ​The presence of relatively high concentrationsof particulates may indicate inadequate ventilation or filtration. There is limited
evidence that particulate matter concentrations may be related to the rate ofviral spread under specific circumstances (e.g., ​Setti et al. 2020​ based on datafrom Northern Italy). High ambient particulate concentrations have been linked
to greater incidence of chronic respiratory diseases such as COPD and asthma,
and a host of other health issues. The respiratory conditions may in turnexacerbate the susceptibility to, and impact of, COVID19 on individuals.

Each metric will be assessed to determine the fraction of occupied space and timecovered by measurements. In turn, these data are interpreted to estimate the fractionof occupied hours when conditions are in the good, acceptable, or “investigate”
range.

Sample IAQ Measurements
Projects may have any combination of IAQ measurements. The following example
illustrates information that may be provided for a project with relative humidity (RH) andtotal volatile organic compounds (TVOC).
Relative humidity
Spatial coverage● RH is measured by stationary, in situ sensors for each HVAC zone
● The spatial coverage is estimated at 100% for the period
Temporal coverage● RH is measured by in situ sensors for each HVAC zone at 5 min intervals● The facility HVAC service operates 60 hours.
● There is at least one RH measurement per zone for all 60 hours● The temporal coverage is estimated at 100% for the period

21Performance● RH data ranged from 41% to 58% across all zones and all measurements during
operating hours.
● The performance value is 100% in “good” status, 0% in “warning”, and 0% in“investigate”.
Carbon dioxide
Spatial coverage● CO​2​ is measured by hand-held sensors in 10 out of 100 rooms or enclosed spaces.
● The spatial coverage is estimated at 10%.
Temporal coverage● CO​2​ measurements occurred over 2 hours during the period● The facility operates 60 hours.
● The temporal coverage is estimated at 3% for the period
Performance● CO​2​ measurements ranged from 500 ppm to 1,300 pm.
● The performance value is 50% “good” (≲750 ppm), 30% in “warning” (750-1000ppm), and 20% in “investigate” (>1,000 ppm).
The other variables follow a similar pattern.

IAQ Comprehensiveness Score
Arc will generate an IAQ Comprehensiveness Score (“Comp Score”). The Comp Score
will reflect a 0 to 100% measure based on spatial coverage (floor area, rooms, or HVAC
zones), temporal coverage (operating hours), and performance (time in “good”
range). Each of these factors has a maximum value of 100, so the maximum value permeasurement is 300. This is repeated across all six measurements (relative humidity,
CO2, TVOC, PM1, PM2.5, and PM10).
A few details about how this is computed:
Spatial coverage ​indicates the fraction of the proj covered by each type of sensor.
Users should assume that an individual sensor covers approximately 500 square meters(5,280 square feet) (​RESET Air Standard for Commercial Interiors​) or following guidancefrom their vendor or product manufacturer (e.g., ​arbnco Best Practice Guide​).

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While sensor coverage will differ based on building layouts and installation practicalities,
projects should aim for the smallest effective coverage area of a sensor, and thecoverage area of a single sensor should not exceed 500 m2. ​For example, at least one
sensor in each HVAC zone or enclosed room could suffice for adequate coverage,
provided those zones or enclosed rooms are smaller than 500 m​2​ each. .
As examples:●●●

Measurements from one relative humidity sensor covering 500 m2 in a 5,000
square meter open space would be presumed and documented to provide acoverage of 10% (500 m​2​ / 5000 m​2​).
Estimate an effective radius around each sensor and derive the covered area
based on manufacturer or vendor guidance (e.g., arbnco ​Best Practice Guide​).
Follow and reference guidance from a third-party standard, such the RESET Air
Standard 2.0 for the design and operation of monitoring networks.

Another strategy would be to use in-duct or air distribution system-based
measurements. These may provide an efficient way to cover large fractions of a facility.
In this case, coverage is based on the floor area covered by the air distribution system:●

Air quality can be monitored within the mechanical system. communicating thequality of the air being delivered by landlords and operators to occupants. An
in-duct strategy should ensure that sensors are installed on supply air ducts andcover a combined floor area equivalent to no less than 30% of the building area(​RESET Air Standard for Core & Shell​).

Arc assumes that coverage continues from the last reported value through the present
unless this value is changed due to reorganisation of space or sensor layouts. Arc
combines values as an average of daily values to provide an estimate for a given time
period.

Tips for Entering Spatial Data Coverage
Some users may not be able to provide a quantitative estimate of spatial data
coverage. We know that there are many potentially confounding factors andunknowns (e.g., the area covered by any given sensor). It is important to rememberthat the purpose is to provide a rough estimate of the fraction occupied spaceassociated with each measurement (i.e., are you covering a small fraction of thearea, most of the space, or all of the space).

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If a quantitative estimate is not possible, users may estimate coverage and enter thefollowing values:●

Low Coverage:​ <25% of occupied space is associated with measurements○ Enter 25% for the applicable date range●

Medium Coverage: ​25%-75% of occupied space is associated withmeasurements○ Enter 50% for the applicable date range●

High Coverage:​ >75% of occupied space is associated with measurements○ Enter 100% for the applicable date range

Describe your estimate with a piece of document. This can be a simple note
explaining your rationale.

Temporal coverage​ indicates the fraction of time covered by IAQ measurements
during the last 30 days. For Arc, a time period is “covered” if at least one measurement
is taken during the period in a project.
For the purpose of infection control, we are assuming 24/7 operations and 1 hour as afundamental unit of temporal coverage (a.k.a., freshness period for measurements).
Consequently, temporal coverage is defined as the percentage of hours within aperiod that have one or more readings for a given parameter. Additional
measurements during a given period do not increase coverage (i.e., temporal
coverage has a maximum value of 100% which is satisfied by at least one reading eachhour). This means that 1 day has a maximum of 24 readings that will count towards
temporal coverage.
As an example, one measurement taken during a 1-year period would provide acoverage of 0.01% (1/8760); presuming 24/7 operations. Considerations for the
calculation include measurement rate (interval between observations) and reportinginterval (period over which measurements are aggregated and sent to Arc).
A high measurement rate, e.g., those recommended by standards such as WELL and
RESET, are better for a richer, more representative characterisation of IEQ. To keep thismetric simple, Arc requires a report only every hour (i.e., the reporting interval).

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Arc assumes that coverage continues from the last reported value through the present
unless this value is changed with new value. Arc combines values as an average ofdaily values to provide an estimate for a given time period.

Tips for Entering Temporal Data Coverage
Some users may not be able to provide a quantitative estimate of temporal data
coverage. We know that there are many potentially confounding factors andunknowns. It is important to remember that the purpose is to provide a rough estimateof the fraction occupied hours associated with each measurement (i.e., are you
covering a small fraction, most hours, or all of them).
If a quantitative estimate is not possible, users may estimate coverage and enter thefollowing values:●

Low Coverage:​ <25% of occupied hours are associated with a measurement○ Enter 25% for the applicable date range.

●

Medium Coverage: ​25%-75% of occupied hours are associated with ameasurement○ Enter 50% for the applicable date range.

●

High Coverage:​ >75% of occupied hours are associated with a measurement○ Enter 100% for the applicable date range.

Describe your estimate with a piece of document. This can be a simple note
explaining your rationale.

Performance​ is divided by thresholds into three categories: good, warning, andinvestigate. Each period is assigned to one of the three categories.
Performance is typically integrated over some period of time, most often hours or days.
These periods may contain any number of sensor readings. The intent is tocommunicate the percentage of time in each category. For example:●●

If hourly (for sub-hourly) data are available, Performance would be calculated
as the average of hourly values. Missing values would be excluded from
Performance, because they are already accounted for in the preceding metrics.
If daily data are available, Performance would be calculated as the average ofdaily values. Again, missing values would be excluded.

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The result would be the average fraction of periods in each of the three categories overthe last 30 days. Data older than 30 days do not contribute to the IAQ
Comprehensiveness Comp Score.
The IAQ Comp Score combines the three equal elements:●●●

Spatial Coverage
Temporal Coverage
Performance (as the fraction of time in the “good” condition)

The result is that a project has a maximum score of 300 reflecting thecomprehensiveness of data and measured performance. The same structure is used foreach of the sub-components (i.e., relative humidity, CO​2​, TVOC, and PM).
Table 3. D
​ raft thresholds used to assign time in each condition: good, warning, investigate. These thresholds
are subject to further review and adjustment based on sensor uncertainty. Source: Parag Rastogi, arbnco.
Low
Parameter

Investigate

Warning

High
Good(Acceptabl
e)

CO​2

350

n/a

Warning

Investigate

Units

Includedin Comp
Score

>1000

ppm

Yes

(Acceptable)

350-750

1,000

SourceCIBSE Guide A
2018 (Table 4.1,
4.5)
LEED v4.1 O+M
Beta Guide

RH

30

30-40

40-60

60-70

>70

%

Yes

CIBSE Guide A
2018

TVOC2

0

n/a

0-175

175-200>200µg/m​3Yes

RESET v2 2018

PM​1

0

n/a

0-12

12-15

>15

µg/m​3

No

TBD

PM​2.5

0

n/a

0-12

12-15

>15

µg/m​3Yes

RESET v2 2018
WELL v2 2020,
Optimization 1

PM​10

2

0

n/a

0-30

30-35

>35

µg/m​3

No

WELL v2 2020,
Optimization 1

TVOC measurements in ppb should be converted to µg/m​3​ using a conversion factor of 3.767.

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Note on Data Quality
Objective measures of data quality are not currently part of the IAQ Comp Score.
However, the quality of IAQ measurements is a significant management issue, and it
varies significantly based on a variety of factors, including sampling design, sensor
placement, sensor capabilities, sensor maintenance, data processing, and more (​RESETStandard​)​. An extensive peer-review literature is emerging in this area with publications
such as ​Sun et al. 2019​ and ​Chojer et al. 2020​, and the ​U.S. Environmental Protection
Agency Air Sensor Toolbox​. Arc Re-Entry users may consider the benefits of third-party
accredited hardware as one element of a comprehensive strategy to promote data
quality.
Table 4. C
​ omparison of the existing Arc indoor air quality with the new re-entry enhanced indoor air quality.
Existing Arc
Indoor Air Quality
Annual measurement of:● 95th percentile CO2 concentration● Maximum TVOC concentration

Re-Entry
Enhanced Indoor Air Quality
Existing Arc occupant survey plus additional criteria:
Data coverage● Fraction of occupied space and timecovered by sensing
Relative humidity● Fraction of occupied hours within optimal RH
range
Particulate matter● Fraction of occupied hours below threshold27

Analysis
Arc provides all users information through the Re-Entry under the Performance tab. This
provides a summary of the overall Comp Score, along with sub-scores for Facility
Management, Occupant Observations, and Indoor Air Quality. This allows users to track
the comprehensiveness of re-entry efforts day-by-day. Note that this contrasts withother Arc reporting, which provides month-by-month trends. Users can view occupant
experiences for specific scopes and groups with the selection tool.
Figure 5. ​The Arc Re-Entry dashboard provides a day-by-day overview of the comprehensiveness of
infection control practices, along with sub-scores for facility management, occupant observations, andindoor air quality.

Arc Essential users can also create and customize a Re-Entry Report. This is available
through the Report tab. Users can select the default Arc logo or upload their own
image.
The project Re-Entry Report provides all the information in the Performance tab, plus a
comparison between the project and all other Re-Entry participants. Over time, Arc
expects to allow users to refine the comparison, such as comparing a project to a
specific portfolio or group. This capability will be more valuable as more data becomes
available.
The Re-Entry Report provides a one-page overview of activities, described as“scorecard”. The scorecard can be distributed separately from the report as an“at-a-glance” summary of infection-control efforts.
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The check marks indicate a positive response, the presence of occupant feedback,and the availability of at least some measured IAQ data in each category. There are
no minimums for these elements at this time; the presence of any data is sufficient toreceive a check mark.
The following sections provide more detailed information about each category,including details about the relationship between management expectations (plans andpolicies) and occupant observations.
Figure 6. ​The Arc Re-Entry Report (available to Arc Essentials subscribers) provides a one-page overview ofpolicy elements and the presence of data from occupants and IAQ measurements.

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Conclusion
The Arc Re-Entry provides practical tools to collect, manage, and interpret information
about facility management, occupant experience, and indoor environmental
conditions. These tools can help inform and improve facility management and support
effectiveness communications with occupants.
Arc Re-Entry does not stand alone. Ideally, it should be deployed as part of acomprehensive infection control management system which includes input from publichealth and industrial hygiene specialists. This type of comprehensive system recognizes
that protection comes from the consistent, end-to-end operation of the management
process, not any single strategy or technology. Arc can support this process, but it
cannot guarantee outcomes.
As part of the right management system, Arc Re-Entry can help build the knowledge
and confidence needed to safely occupy the places where we live, work, and play.

Contact
Contact Chris Pyke (cpyke@arcskoru.com) to provide feedback or get more
information.

About Arc
ArcSkoru (Arc) is a wholly-owned subsidiary of the Green Business Certification, Inc. It isbased in Washington, DC dedicated to making real world performance measurement
an integral and ubiquitous part of green building practice.
Learn more at ​www.arcskoru.com

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