R401.3 Certificate (Mandatory). 

A permanent certificate shall be completed by the builder or registered design professional and posted on a wall in 

the space where the furnace is located, a utility room or an approved location inside the building. Where located on 

an electrical panel, the certificate shall not cover or obstruct the visibility of the circuit directory label, service 

disconnect label or other required labels. The certificate shall list the predominant R-values of insulation installed in 

or on ceiling/roof, walls, foundation (slab, basement wall, crawlspace wall and floor) and ducts outside conditioned 

spaces; U-factors for fenestration and the solar heat gain coefficient (SHGC) of fenestration, and the results from 

any required duct system and building envelope air leakage testing done on the building. Where there is more than 

one value for each component, the certificate shall list the value covering the largest area. The certificate shall list 

the types and efficiencies of heating, cooling and service water heating equipment. Where a gas-fired unvented room 

heater, electric furnace or baseboard electric heater is installed in the residence, the certificate shall list “gas-fired 

unvented room heater,” “electric furnace” or “baseboard electric heater,” as appropriate. An efficiency shall not be 

listed for gas-fired unvented room heaters, electric furnaces or electric baseboard heaters. 

Refer to the HUD code requirements for data plate/compliance certificates. Suggest 

that information for fenestration U-Values and SHGC be included into the HUD required 

data plate 

R402.4 Air leakage (Mandatory). The building thermal envelope shall be constructed to limit air leakage in accordance with the requirements of Sections R402.4.1 through R402.4.4. 

R402.4.1 Building thermal envelope. The building thermal envelope shall comply with Sections R402.4.1.1 and 

R402.4.1.2. The sealing methods between dissimilar materials shall allow for differential expansion and 

contraction. 

R402.4.1.1 Installation. The components of the building thermal envelope as listed in Table R402.4.1.1 shall 

be installed in accordance with the manufacturer’s instructions and the criteria listed in Table R402.4.1.1, as 

applicable to the method of construction. Where required by the code official, an approved third party shall 

inspect all components and verify compliance. 

R402.4.1.2 Testing. The building or dwelling unit shall be tested and verified as having an air leakage rate not 

exceeding five air changes per hour in Climate Zones 1 and 2, and three air changes per hour in Climate Zones 

3 through 8. Testing shall be conducted in accordance with ASTM E 779 or ASTM E 1827 and reported at a 

pressure of 0.2 inch w.g. (50 Pascals). Where required by the code official, testing shall be conducted by an 

approved third party. A written report of the results of the test shall be signed by the party conducting the test 

and provided to the code official. Testing shall be performed at any time after creation of all penetrations of 

the building thermal envelope. 

During testing: 

1 Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended 

weatherstripping or other infiltration control measures. 

2 Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed 

beyond intended infiltration control measures. 

3 Interior doors, if installed at the time of the test, shall be open. 

4 Exterior doors for continuous ventilation systems and heat recovery ventilators shall be closed and sealed. 

5 Heating and cooling systems, if installed at the time of the test, shall be turned off. 

6 Supply and return registers, if installed at the time of the test, shall be fully open. 

Yellow highlighted section – deferred to the Emanuel proposal 
R402.4.2 Fireplaces. New wood-burning fireplaces shall have tight-fitting flue dampers or doors, and outdoor 

combustion air. Where using tight-fitting doors on factory-built fireplaces listed and labeled in accordance with 

UL 127 the doors shall be tested and listed for the fireplace. Where using tight-fitting doors on masonry 

fireplaces, the doors shall be listed and labeled in accordance with UL 907. 

Justification - §3280.709(g)(1) essentially covers the same requirements. the HUD 

code also references UL 127, albeit the 1996 section with 99 amendments 
R402.4.3 Fenestration air leakage. Windows, skylights and sliding glass doors shall have an 

air infiltration rate of no more than 0.3 cfm per square foot (1.5 L/s/m

2

), and swinging doors 

no more than 0.5 cfm per square foot (2.6 L/s/m

2

), when tested according to NFRC 400 or 

AAMA/ WDMA/CSA 101/I.S.2/A440 by an accredited, independent laboratory and listed and 

labeled by the manufacturer. 

 

Exception: Site-built windows, skylights and doors. 

Justification – air leakage requirements are part of existing AAMA fenestration standards for 

HUD housing. Tightening up the windows any further will impact the force necessary to open 

the window having a detrimental impact on existing HUD requirements for egress windows. 

(source – Rob Luter, Lippert Components) 

R402.5 Maximum fenestration U-factor and SHGC (Mandatory). The area-weighted average 

maximum fenestration U-factor permitted using tradeoffs from Section [Total UA/REScheck option] 

R402.1.5 or [Uo option] R405 shall be 0.48 in Climate Zones 4 and 5 and 0.40 in HUD Climate Zones 2 6

through 3 8 for vertical fenestration, and 0.75 in Climate Zones 4 through 8 for skylights. The 

area-weighted average maximum fenestration SHGC permitted using tradeoffs from Section [Total 

UA/REScheck option] or [Uo option] R405 in HUD Climate Zones 1 through 2 3 shall be 0.40 0.50.
COMPONENT AIR BARRIER CRITERIA INSULATION INSTALLATION CRITERIA 

General requirements 

A continuous air barrier shall be installed in the 

building envelope. 

The exterior thermal envelope contains a continuous 

air barrier

Breaks or joints in the air barrier shall be sealed. 

Air-permeable insulation shall not be used as a 

sealing material. 

Ceiling/attic 

The air barrier in any dropped ceiling/soffit shall be 

aligned with the insulation and any gaps in the air 

barrier shall be sealed. 

Access openings, drop down stairs or knee wall doors 

to unconditioned attic spaces shall be sealed. 

The insulation in any dropped ceiling/soffit shall 

be aligned with the air barrier. 

Walls 

The junction of the foundation and sill plate shall be 

sealed. 

The junction of the top plate and the ceiling top of 

along exterior walls shall be sealed. 

Knee walls shall be sealed. 

The junction of the bottom plate and the floor along 

exterior walls shall be sealed 

Cavities within a stud bay caused by blocking, 

layflats or headers within corners and headers of 

frame exterior walls shall be insulated by 

completely filling the cavity with a material 

having a thermal resistance of R-3 per inch 

minimum. 

Exterior thermal envelope insulation for framed 

walls shall be installed in substantial contact and 

continuous alignment with the air barrier. 

Windows, skylights and doors 

The space between window/door jambs and framing, 

and skylights and framing shall be sealed. 

Rim joists Rim joists shall include the air barrier. Rim joists shall be insulated. 

Floors (including above garage and 

cantilevered floors) 

The air barrier shall be installed at any exposed edge 

of insulation. The bottom board may serve as the air 

barrier

Floor framing cavity insulation shall be installed 

to maintain permanent contact with the underside 

of subfloor decking, or floor framing cavity 

insulation shall be permitted to be in contact with 

the top side of sheathing, or continuous insulation 

installed on the underside of floor framing and 

extends from the bottom to the top of all 

perimeter floor framing members. 

Crawl space walls 

Exposed earth in unvented crawl spaces shall be 

covered with a Class I vapor retarder with overlapping 

joints taped. 

Where provided instead of floor insulation, 

insulation shall be permanently attached to the 

crawlspace walls. 

Shafts, penetrations 

Duct shafts, utility penetrations, and flue shafts that 

penetrate the air barrier opening to exterior or 

unconditioned space shall be sealed. 

Narrow cavities 

Batts in narrow cavities shall be cut to fit, or 

narrow cavities shall be filled by insulation that 

on installation readily conforms to the available 

cavity space. 

Garage separation 

Air sealing shall be provided between the garage and 

conditioned spaces. 

Recessed lighting 

Recessed light fixtures installed in the building 

thermal envelope shall be sealed to the drywall. 

Recessed light fixtures installed in the building 

thermal envelope shall be air tight and IC rated. 

Plumbing and wiring 

Batt insulation shall be cut neatly to fit around 

wiring and plumbing in exterior walls, or

insulation that on installation readily conforms to 

available space shall extend behind piping and 

wiring. 

Shower/tub on exterior wall 

The air barrier installed at exterior walls adjacent to 

showers and tubs shall separate them from the 

showers and tubs. 

Exterior walls adjacent to showers and tubs shall 

be insulated. 

Electrical/phone box on exterior walls 

The air barrier shall be installed behind electrical or 

communication boxes or air-sealed boxes shall be 

installed. the air barrier shall be sealed around the 

box penetration 

HVAC register boots 

HVAC register boots that penetrate building thermal 

envelope shall be sealed to the subfloor or drywall. 

Concealed sprinklers 

When required to be sealed, concealed fire sprinklers 

shall only be sealed in a manner that is recommended 

by the manufacturer. Caulking or other adhesive 

sealants shall not be used to fill voids between fire 

sprinkler cover plates and walls or ceilings. 

TABLE R402.4.1.1 AIR BARRIER AND INSULATION INSTALLATION 

a. In addition, inspection of log walls shall be in accordance with the provisions of ICC-400. 
R403.1.2 Heat pump supplementary heat (Mandatory). 

Heat pumps having supplementary electric-resistance heat shall have controls that, except 

during defrost, prevent supplemental heat operation when the heat pump compressor can meet 

the heating load. 

R403.5.1 Heated water circulation and temperature maintenance systems (Mandatory).

Heated water circulation systems shall be in accordance with Section R403.5.1.1. Heat trace 

temperature maintenance systems shall be in accordance with Section R403.5.1.2. Automatic 

controls, temperature sensors and pumps shall be accessible. Manual controls shall be readily 

accessible 

R403.5.1.1 Circulation systems. Heated water circulation systems shall be provided with a 

circulation pump. The system return pipe shall be a dedicated return pipe or a cold water 

supply pipe. Gravity and thermosyphon circulation systems shall be prohibited. Controls for 

circulating hot water system pumps shall start the pump based on the identification of a 

demand for hot water within the occupancy. The controls shall automatically turn off the 

pump when the water in the circulation loop is at the desired temperature and when there is no 

demand for hot water. 

R403.5.1.2 Heat trace systems. Electric heat trace systems shall comply with IEEE 515.1 or 

UL 515. Controls for such systems shall automatically adjust the energy input to the heat 

tracing to maintain the desired water temperature in the piping in accordance with the times 

when heated water is used in the occupancy. 

R403.6 Mechanical ventilation (Mandatory). The building shall be provided with 

ventilation that meets the requirements of the International Residential Code or International 

Mechanical Code, as applicable, or with other approved means of ventilation. Outdoor air 

intakes and exhausts shall have automatic or gravity dampers that close when the ventilation 

system is not operating. 

Accept in principle – need to compare with current HUD ventilation requirements 

R403.7 Equipment sizing and efficiency rating (Mandatory). Heating and cooling 

equipment shall be sized in accordance with ACCA Manual S based on building loads 

calculated in accordance with ACCA Manual J or other approved heating and cooling 

calculation methodologies. New or replacement heating and cooling equipment shall have an 

efficiency rating equal to or greater than the minimum required by federal law for the 

geographic location where the equipment is installed. 

Move to parking lot, needs discussion / comparison with current HUD practice 

R404.1.1 Lighting equipment (Mandatory). Fuel gas lighting systems shall not have 

continuously burning pilot lights.