About this chapter: Chapter 4 provides requirements for the thermal envelope of a building, including minimum insulation values for walls, ceiling and floors; maximum fenestration U-factors; minimum fenestration solar heat gain coefficients; and methods for determining building assembly and a total building U-factor. A performance alternative and an energy rating alternative are also provided to allow for energy code compliance other than by the prescriptive method.
Projects shall comply with one of the following:
- Prescriptive Path. Sections R401 through R404 and R407.
- Performance Path. An energy rating index ("ERI") approach, or approved alternative
energy performance rating method in section R406 and the provisions of sections R401 through R404 indicated as "Mandatory." Qualifying approaches under R406 include the
- Certified RESNET HERS rating with Massachusetts amendments.
- Certified Energy Star Homes, Version 3.1.
- Certified Passive house performance method.
Residential buildings in the tropical zone at elevations less than 2,400 feet (731.5 m) above sea level shall be deemed to be in compliance with this chapter provided that the following conditions are met:
- Not more than one-half of the occupied space is air conditioned.
- The occupied space is not heated.
- Solar, wind or other renewable energy source supplies not less than 80 percent of the energy for service water heating.
- Glazing in conditioned spaces has a solar heat gain coefficient of less than or equal to 0.40, or has an overhang with a projection factor equal to or greater than 0.30.
- Permanently installed lighting is in accordance with Section R404.
- The exterior roof surface complies with one of the options in Table C402.3 or the roof or ceiling has insulation with an R-value of R-15 or greater. Where attics are present, attics above the insulation are vented and attics below the insulation are unvented.
- Roof surfaces have a slope of not less than onefourth unit vertical in 12 units horizontal (21-percent slope). The finished roof does not have water accumulation areas.
- Operable fenestration provides a ventilation area of not less than 14 percent of the floor area in each room. Alternatively, equivalent ventilation is provided by a ventilation fan.
- Bedrooms with exterior walls facing two different directions have operable fenestration on exterior walls facing two directions.
- Interior doors to bedrooms are capable of being secured in the open position.
- A ceiling fan or ceiling fan rough-in is provided for bedrooms and the largest space that is not used as a bedroom.
- 1.1. Those with a peak design rate of energy usage less than 3.4 Btu/h • ft2 (10.7 W/m2) or 1.0 watt/ft2 of floor area for space-conditioning purposes.
- 1.2. Those that do not contain conditioned space.
- Log homes designed in accordance with ICC 400.
INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa
|3||0.32||0.55||0.25||38||20 or 13+5h||8/13||19||5/13f||0||5/13|
|0.32||0.55||0.40||49||20 or 13+5h||8/13||19||10/13||10, 2 ft||10/13|
|0.30||0.55||NR||49||20 or 13+5h||13/17||30g||15/19||10, 2 ft||15/19|
|6||0.30||0.55||NR||49||20+5h or 13+10h||15/20||30g||15/19||10, 4 ft||15/19|
|7 and 8||0.30||0.55||NR||49||20+5h or 13+10h||19/21||38g||15/19||10, 4 ft||15/19|
NR = Not Required. For SI: 1 foot = 304.8 mm.
- R-values are minimums. U-factors and SHGC are maximums. Where insulation is installed in a cavity that is less than the label or design thickness of the insulation, the installed R-value of the insulation shall be not less than the R-value specified in the table.
- "10/13" means R-10 continuous insulation on the interior or exterior of the home or R-13 cavity insulation on the interior of the basement wall. "15/19" means R-15 continuous insulation on the interior or exterior of the home or R-19 cavity insulation at the interior of the basement wall. Alternatively, compliance with "15/19" shall be R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulation on the interior or exterior of the home.
- R-5 insulation shall be provided under the full slab area of a heated slab in addition to the required slab edge insulation R-value for slabs. as indicated in the table. The slab edge insulation for heated slabs shall not be required to extend below the slab.
- There are no SHGC requirements in the Marine Zone.
- Basement wall insulation is not required in warm-humid locations as defined by Figure R301.1 and Table R301.1.
- Alternatively, insulation sufficient to fill the framing cavity and providing not less than an R-value of R-19.
- The first value is cavity insulation, the second value is continuous insulation. Therefore, as an example, "13+5" means R-13 cavity insulation plus R-5 continuous insulation.
- Mass walls shall be in accordance with Section R402.2.5. The second R-value applies where more than half of the insulation is on the interior of the mass wall.
An assembly with a U-factor equal to or less than that specified in Table R402.1.4 shall be an alternative to the R-value in Table R402.1.2.
|4 except Marine||0.32||0.55||0.026||0.060||0.098||0.047||0.059||0.065|
|5 and Marine 4||0.30||0.55||0.026||0.060||0.082||0.033||0.050||0.055|
|7 and 8||0.30||0.55||0.026||0.045||0.057||0.028||0.050||0.055|
- Nonfenestration U-factors shall be obtained from measurement, calculation or an approved source.
- Mass walls shall be in accordance with Section R402.2.5. Where more than half the insulation is on the interior, the mass wall U-factors shall not exceed 0.17 in Climate Zone 1, 0.14 in Climate Zone 2, 0.12 in Climate Zone 3, 0.087 in Climate Zone 4 except Marine, 0.065 in Climate Zone 5 and Marine 4, and 0.057 in Climate Zones 6 through 8.
- In warm-humid locations as defined by Figure R301.1 and Table R301.1, the basement wall U-factor shall not exceed 0.360.
Access doors from conditioned spaces to unconditioned spaces such as attics and crawl spaces shall be weatherstripped and insulated to a level equivalent to the insulation on the surrounding surfaces. Access that prevents damaging or compressing the insulation shall be provided to all equipment. Where loose-fill insulation is installed, a wood-framed or equivalent baffle or retainer shall be installed to prevent the loose-fill insulation from spilling into the living space when the attic access is opened. The baffle or retainer shall provide a permanent means of maintaining the installed R-value of the loose-fill insulation.
Exception: Vertical doors providing access from conditioned spaces to unconditioned spaces that comply with the fenestration requirements of Table R402.1.2 based on the applicable climate zone specified in Chapter 3.
Mass walls where used as a component of the building thermal envelope shall be one of the following:
- Above-ground walls of concrete block, concrete, insulated concrete form, masonry cavity, brick but not brick veneer, adobe, compressed earth block, rammed earth, solid timber or solid logs.
- Any wall having a heat capacity greater than or equal to 6 Btu/ft2 ● °F (123 kJ/m2 ● K).
Steel-frame ceilings, walls, and floors shall comply with the insulation requirements of Table R402.2.6 or the U-factor requirements of Table R402.1.4. The calculation of the U-factor for a steel-frame envelope assembly shall use a series-parallel path calculation method.
STEEL-FRAME CEILING, WALL AND FLOOR INSULATION R-VALUES
|Steel Truss Ceilingsb|
|R-30||R-38 or R-30 + 3 or R-26 + 5|
|R-38||R-49 or R-38 + 3|
|R-49||R-38 + 5|
|Steel Joist Ceilingsb|
|R-30||R-38 in 2 × 4 or 2 × 6 or 2 × 8 R-49|
in any framing
|R-38||R-49 in 2 × 4 or 2 × 6 or 2 × 8 or 2 × 10|
|Steel-Framed Wall, 16 inches on center|
|R-13||R-13 + 4.2 or R-21 + 2.8 or|
R-0 + 9.3 or R-15 + 3.8 or R-21 + 3.1
|R-13 + 3||R-0 + 11.2 or R-13 + 6.1 or R-15 + 5.7 or|
R-19 + 5.0 or R-21 + 4.7
|R-20||R-0 + 14.0 or R-13 + 8.9 or R-15 + 8.5 or |
R-19 + 7.8 or R-19 + 6.2 or R-21 + 7.5
|R-20 + 5||R-13 + 12.7 or R-15 + 12.3 or R-19 + 11.6 or |
R-21 + 11.3 or R-25 + 10.9
|R-21||R-0 + 14.6 or R-13 + 9.5 or R-15 + 9.1 or|
R-19 + 8.4 or R-21 + 8.1 or R-25 + 7.7
|Steel Framed Wall, 24 inches on center|
|R-13||R-0 + 9.3 or R-13 + 3.0 or R-15 + 2.4|
|R-13 + 3||R-0 + 11.2 or R-13 + 4.9 or R-15 + 4.3 or|
R-19 + 3.5 or R-21 + 3.1
|R-20||R-0 + 14.0 or R-13 + 7.7 or R-15 + 7.1 or|
R-19 + 6.3 or R-21 + 5.9
|R-20 + 5||R-13 + 11.5 or R-15 + 10.9 or R-19 + 10.1 or|
R-21 + 9.7 or R-25 + 9.1
|R-21||R-0 + 14.6 or R-13 + 8.3 or R-15 + 7.7 or|
R-19 + 6.9 or R-21 + 6.5 or R-25 + 5.9
|Steel Joist Floor|
|R-13||R-19 in 2 × 6, or R-19 + 6 in 2 × 8 or 2 × 10|
|R-19||R-19 + 6 in 2 × 6, or R-19 + 12 in 2 × 8 or 2 × 10|
Floor framing-cavity insulation shall be installed to maintain permanent contact with the underside of the subfloor decking.
Exception: As an alternative, the floor framing-cavity insulation shall be in contact with the topside of sheathing or continuous insulation installed on the bottom side of floor framing where combined with insulation that meets or exceeds the minimum wood frame wall R-value in Table R402.1.2 and that extends from the bottom to the top of all perimeter floor framing members.
- The minimum ceiling insulation R-values shall be R-19 in Climate Zones 1 through 4 and R-24 in Climate Zones 5 through 8.
- The minimum wall insulation R-value shall be R-13 in all climate zones. Walls separating a sunroom with a thermal isolation from conditioned space shall comply with the building thermal envelope requirements of this code.
Dynamic glazing shall be permitted to satisfy the SHGC requirements of Table R402.1.2 provided that the ratio of the higher to lower labeled SHGC is greater than or equal to 2.4, and the dynamic glazing is automatically controlled to modulate the amount of solar gain into the space in multiple steps. Dynamic glazing shall be considered separately from other fenestration, and area-weighted averaging with other fenestration that is not dynamic glazing shall be prohibited.
Exception: In Climate Zones 2 through 8, for sunrooms with thermal isolation and enclosing conditioned space, the fenestration U-factor shall not exceed 0.45 and the skylight U-factor shall not exceed 0.70.
The components of the building thermal envelope as indicated in Table R402.4.1.1 shall be installed in accordance with the manufacturer's instructions and the criteria indicated 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.
AIR BARRIER AND INSULATION INSTALLATIONa
|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 continuousair barrier shall be sealed.
|All insulation shall be installed at Grade I quality in accordance with ICC/RESNET 301.
Air-permeable insulation shall not be used as a|
|Ceiling/attic||The air barrier in any dropped ceiling or soffit shall be|
aligned with the insulation and any gaps in the airbarrier shall be sealed.
Access openings, drop down stairs or knee wall doorsto 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 top of exterior
walls shall be sealed.Knee walls shall be sealed.
|Cavities within corners and headers of frame|
walls shall be insulated by completely filling thecavity with a material having a thermal resistance,
R-value, of not less than R-3 per inch.Exterior thermal envelope insulation for framed
walls shall be installed in substantial contact andcontinuous alignment with the air barrier.
|Windows, skylights and doors||The space between framing and skylights, and the jambs|
of windows and doors, shall be sealed.
|Rim joists||Rim joists shall include the air barrier.||Rim joists shall be insulated.|
|Floors, including cantilevered |
floors and floors abovegarages
|The air barrier shall be installed at any exposed edge of|
|Floor framing cavity insulation shall be installed to|
maintain permanent contact with the underside ofsubfloor decking. Alternatively, floor framing
cavity insulation shall be in contact with the top sideof sheathing, or continuous insulation installed on
the underside of floor framing; and shall extendfrom the bottom to the top of all perimeter floor
|Crawl space walls||Exposed earth in unvented crawl spaces shall be|
covered with a Class I vapor retarder withoverlapping joints taped.
|Crawl space insulation, where provided instead of|
floor insulation, shall be permanently attached tothe walls.
|Shafts, penetrations||Duct shafts, utility penetrations, and flue shafts|
opening to exterior or unconditioned space shall besealed.
|Narrow cavities||—||Batts to be installed in narrow cavities shall be cut to|
fit or narrow cavities shall be filled with insulationthat on installation readily conforms to the available
|Garage separation||Air sealing shall be provided between the garage and||—|
|Recessed lighting||Recessed light fixtures installed in the building thermal|
envelope shall be sealed to the finished surface.
|Recessed light fixtures installed in the building|
thermal envelope shall be air tight and IC rated.
|Plumbing and wiring||—||In exterior walls, batt insulation shall be cut neatly to|
fit around wiring and plumbing, or insulation, thaton 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 the wall from theshower or tub.
|Exterior walls adjacent to showers and tubs shall|
|Electrical/phone box on exterior walls||The air barrier shall be installed behind electrical and|
communication boxes. Alternatively, air-sealed boxesshall be installed.
|HVAC register boots||HVAC supply and return register boots that penetrate|
building thermal envelope shall be sealed to the subfloor,wall covering or ceiling penetrated by the boot.
|Concealed sprinklers||Where required to be sealed, concealed fire sprinklers|
shall only be sealed in a manner that is recommendedby the manufacturer. Caulking or other adhesive
sealants shall not be used to fill voids between firesprinkler cover plates and walls or ceilings.
- Inspection of log walls shall be in accordance with the provisions of ICC 400.
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 RESNET/ICC 380, 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.
- Exterior windows and doors, fireplace and stove doors shall be closed, but not sealed, beyond the intended weatherstripping or other infiltration control measures.
- Dampers including exhaust, intake, makeup air, backdraft and flue dampers shall be closed, but not sealed beyond intended infiltration control measures.
- Interior doors, where installed at the time of the test, shall be open.
- Exterior or interior terminations for continuous ventilation systems shall be sealed.
- Heating and cooling systems, where installed at the time of the test, shall be turned off.
- Supply and return registers, where installed at the time of the test, shall be fully open.
Windows, skylights and sliding glass doors shall have an air infiltration rate of not greater than 0.3 cfm per square foot (1.5 L/s/m2), and for swinging doors, not greater than 0.5 cfm per square foot (2.6 L/s/m2), when tested in accordance with 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.
In Climate Zones 3 through 8, where open combustion air ducts provide combustion air to open combustion fuel burning appliances, the appliances and combustion air opening shall be located outside the building thermal envelope or enclosed in a room that is isolated from inside the thermal envelope. Such rooms shall be sealed and insulated in accordance with the envelope requirements of Table R402.1.2, where the walls, floors and ceilings shall meet not less than the basement wall R-value requirement. The door into the room shall be fully gasketed and any water lines and ducts in the room insulated in accordance with Section R403. The combustion air duct shall be insulated where it passes through conditioned space to an R-value of not less than R-8.
- Direct vent appliances with both intake and exhaust pipes installed continuous to the outside.
- Fireplaces and stoves complying with Section R402.4.2 and Section R1006 of the International Residential Code.
Supply and return ducts in attics shall be insulated to an R-value of not less than R-8 for ducts 3 inches (76 mm) in diameter and larger and not less than R-6 for ducts smaller than 3 inches (76 mm) in diameter. Supply and return ducts in other portions of the building shall be insulated to not less than R-6 for ducts 3 inches (76 mm) in diameter and not less than R-4.2 for ducts smaller than 3 inches (76 mm) in diameter.
Ducts shall be pressure tested to determine air leakage by one of the following methods:
- Rough-in test: Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25 Pa) across the system, including the manufacturer's air handler enclosure if installed at the time of the test. Registers shall be taped or otherwise sealed during the test.
- Postconstruction test: Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25 Pa) across the entire system, including the manufacturer's air handler enclosure. Registers shall be taped or otherwise sealed during the test.
- A duct air-leakage test shall not be required where the ducts and air handlers are located entirely within the building thermal envelope.
- A duct air-leakage test shall not be required for ducts serving heat or energy recovery ventilators that are not integrated with ducts serving heating or cooling systems.
Post-construction or rough-in testing and verification shall be done by a HERS Rater, HERS Rating Field Inspector, or an applicable BPI Certified Professional. A written report of the results of the test shall be signed by the party conducting the test and provided to the code official.
- Rough-in test: The total leakage shall be less than or equal to 4 cubic feet per minute (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area where the air handler is installed at the time of the test. Where the air handler is not installed at the time of the test, the total leakage shall be less than or equal to 3 cubic feet per minute (85 L/min) per 100 square feet (9.29 m2) of conditioned floor area.
- Postconstruction test: Total leakage shall be less than or equal to 4 cubic feet per minute (113.3 L/min) per 100 square feet (9.29 m2) of conditioned floor area.
- The supply and return ducts shall have an insulation R-value not less than R-8.
- At all points along each duct, the sum of the ceiling insulation R-value against and above the top of the duct, and against and below the bottom of the duct, shall be not less than R-19, excluding the R-value of the duct insulation.
- The duct system shall be located completely within the continuous air barrier and within the building thermal envelope.
- 2.1. The air handler is located completely within the continuous air barrier and within the building thermal envelope.
- 2.2. The duct leakage, as measured either by a rough-in test of the ducts or a post-construction total system leakage test to outside the building thermal envelope in accordance with Section R403.3.4, is less than or equal to 1.5 cubic feet per minute (42.5 L/min) per 100 square feet (9.29 m2) of conditioned floor area served by the duct system.
- 2.3. The ceiling insulation R-value installed against and above the insulated duct is greater than or equal to the proposed ceiling insulation R-value, less the R-value of the insulation on the duct.
Demand recirculation water systems shall have controls that comply with both of the following:
- The controls shall start the pump upon receiving a signal from the action of a user of a fixture or appliance, sensing the presence of a user of a fixture or sensing the flow of hot or tempered water to a fixture fitting or appliance.
- The controls shall limit the temperature of the water entering the cold water piping to not greater than 104°F (40°C).
Insulation for hot water piping with a thermal resistance, R-value, of not less than R-3 shall be applied to the following:
- Piping 3/4 inch (19.1 mm) and larger in nominal diameter.
- Piping serving more than one dwelling unit.
- Piping located outside the conditioned space.
- Piping from the water heater to a distribution manifold.
- Piping located under a floor slab.
- Buried piping.
- Supply and return piping in recirculation systems other than demand recirculation systems.
- R406.3 Equation 4-1:
Ventilation rate, CFM = (0.01 x total square foot area of house) + [7.5 x (number of bedrooms + 1);
- Energy Star Homes Version, 3.1.;
- ASHRAE 62.2—2013; or
- the following formula for one- and two-family dwellings and townhouses of three or less
stories above grade plane:
Q = .03 x CFA + 7.5 x (Nbr + 1) - 0.052 x Q50 x S x WSF
Where: CFA is the conditioned floor area in ft2
Nbr is the number of bedrooms
Q50 is the verified blower door air leakage rate in cfm measured at 50 Pascals
S is the building height factor determined by this table:
Stories above grade plane 1 2 3 S 1.00 1.32 1.55
WSF is the shielded weather factor as determined by this table:
County WSF Barnstable 0.6 Berkshire 0.52 Bristol 0.54 Dukes 0.59 Essex 0.58 Franklin 0.52 Hampden 0.49 Hampshire 0.59 Middlesex 0.55 Nantucket 0.61 Norfolk 0.52 Plymouth 0.53 Suffolk 0.66 Worcester 0.59
Fans used to provide whole-house mechanical ventilation shall meet the efficacy requirements of Table R403.6.1.
Exception: Where an air handler that is integral to tested and listed HVAC equipment is used to provide whole-house mechanical ventilation, the air handler shall be powered by an electronically commutated motor.
WHOLE-HOUSE MECHANICAL VENTILATION SYSTEM FAN EFFICACYa
|FAN LOCATION||AIR FLOW RATE MINIMUM|
|AIR FLOW RATE MAXIMUM|
|HRV or ERV||Any||1.2 cfm/watt||Any|
|Range hoods||Any||2.8 cfm/watt||Any|
|In-line fan||Any||2.8 cfm/watt||Any|
|Bathroom, utility room||10||1.4 cfm/watt||< 90|
|Bathroom, utility room||90||2.8 cfm/watt||Any|
For SI: 1 cfm = 28.3 L/min.
- When tested in accordance with HVI Standard 916.
- Ventilation air inlets in the wall shall be separated from dryer exhausts and contamination sources exiting through the roof by a minimum of three feet.
- No minimum separation distance shall be required between local exhaust outlets in kitchens/bathrooms and windows.
- Vent terminations that meet the requirements of the National Fuel Gas Code (NFPA 54/ANSI Z223.1) or equivalent.
Time switches or other control methods that can automatically turn off and on according to a preset schedule shall be installed for heaters and pump motors. Heaters and pump motors that have built-in time switches shall be in compliance with this section.
- Where public health standards require 24-hour pump operation.
- Pumps that operate solar- and waste-heat-recovery pool heating systems.
Outdoor heated pools and outdoor permanent spas shall be provided with a vapor-retardant cover or other approved vapor-retardant means.
Exception: Where more than 75 percent of the energy for heating, computed over an operation season of not less than three calendar months, is from a heat pump or an on-site renewable energy system, covers or other vapor-retardant means shall not be required.
- ENERGY STAR Homes 3.1 Path. New buildings or additions to an existing building, building system or portion thereof shall be certified to conform to the ENERGY STAR Certified Homes, Version 3.1 standard.
- Passive House Institute US ("PHIUS") or Passive House Institute ("PHI") Approved Software. Projects pre-certified through PHIUS or PHI, with a certified Passive House Consultant or certified Passive House Designer verified "as-built" report demonstrating compliance with the PHIUS or PHI standard.
- Any other software approved by the Board of Building Regulations and Standards.
Compliance with this section requires that the provisions identified in Sections R401 through R404 indicated as "Mandatory" and Section R403.5.3 be met. The building thermal envelope shall be greater than or equal to levels of efficiency and Solar Heat Gain Coefficients in Table 402.1.1 or 402.1.3 of the 2009 International Energy Conservation Code.
Compliance based on an ERI analysis requires that the rated design be shown to have an ERI less than or equal to the appropriate value indicated in Table R406.4 when compared to the ERI reference design for each dweilings unit prior to credit for onsite renewable electric generation.
MAXIMUM ENERGY RATING INDEX
|Maximum HERS Index Scorea, b|
|On-site Renewable Energy Application||New Construction||Whole House Renovations; Additions|
|Solar Electric Generation||60||70|
|Clean Space Heating||60||70|
|Solar Electric and Clean Space Heating||65||75|
|Solar Electric and DWH||62||72|
|Solar Electric, Clean Space Heating and DHW||67||77|
- a Maximum HERS rating prior to onsite renewable electric generation in accordance with Section R406.4
- b Where on-site renewable energy is included for compliance using the ERI analysis of Section R406.4, the building shall meet the mandatory requirements of Section R406.2, and the building thermal envelope shall be greater than or equal to the levels of efficiency and SHGC in Table R402.1.2 or Table R402.1.4 of the 2015 International Energy Conservation Code.
- Solar Generation. Solar photovoltaic array rated at 2.5 kW or higher shall offset five HERS points.
- Clean Space Heating. Clean biomass heating system, solar thermal array, cold climate air source heat pump having rated coefficient of performance (COP) of at least 1.75 at 5°F, or geothermal heat pump, or a combination of these systems, operating as the primary heating system shall offset five HERS points.
- Renewable Domestic Hot Water Heating (DHW). Solar thermal array or heat pump for primary domestic hot water heating shall offset two HERS points.
- A HERS compliance report which includes a proposed HERS index score of 55 or lower, or otherwise complies via renewable trade-offs;
- A description of the unit's energy features; and
- A statement that the rating index score is "based on plans"
Prior to the issuance of a certificate of occupancy, the following items must be provided to the Building official:
- A copy of the final certificate indicating that the HERS rating index score for each unit is verified to be 55 or less or otherwise complies via renewable trade-offs together with a completed HERS rater verified ENERGY STAR Thermal Enclosure System Rater Checklist.
- A copy of the certificate, as required by Section R401.3 for each unit listing the final HERS index score of the dwelling unit.
- A copy of the preliminary HERS rating, based on plans
- A description of the unit's energy features; and
- A statement that the rating index score is "based on plans"
- A copy of the final ENERGY STAR Homes certificate;
- A copy of the certified final HERS rating; and
- A copy of the signed ENERGY STAR Thermal Enclosure System Rater Checklist.
- A copy of the certificate, as required by Section R401.3 for each unit listing the final HERS index score of the dwelling unit.
- If using PHIUS or PHI Passive House software, prior to the issuance of a building permit,
the following items must be provided to the Building Official:
- A WUFI or PHPP compliance report which demonstrates project compliance with PHIUS+2018 (or newer) or PHI performance requirements;
- A statement that the WUFI or PHPP results are "based on plans";
- Evidence of precertification approval from PHIUS or PHI.
- Prior to the issuance of a certificate of occupancy, the following item(s) must be provided
to the building official:
- An updated WUFI or PHPP compliance report which demonstrates project compliance with PHIUS+2018 (or newer) or PHI performance requirements;
- A copy of the Passive House Rater's test results;
- A statement that the WUFI or PHPP results are "based on 'as-buiit' conditions, incorporating the relevant test results and documented changes to equipment, materials, and assemblies that impact performance".
- More efficient HVAC performance in accordance with Section R407.2
- Heat recovery ventilation (HRV) system or Energy recovery ventilation (ERV) system in accordance with Section R403.6.1. The Exception in R403.6.1 shall not be applied if used for compliance with this Section.
- High efficiency water heater or solar thermal hot water heater in accordance with Section R407.3
- Gas, propane or oil-fired furnaces with a minimum AFUE of 95%
- Gas, propane or oil-fired boilers with a minimum AFUE of 95%
- Closed-loop ground source heat pumps with a minimum COP of 3.5
- Air-source heat pumps with a minimum HSPF of 10
- Natural gas or propane water heating with a minimum Uniform Energy Factor (UEF) of 0.87 or electric heat pump hot water heater with a minimum UEF of 2.2. On-demand natural gas or propane water heaters shall not include any buffer tank or hot water storage capacity outside the water heater itself.
- A solar thermal hot water heating system with a minimum of 40 square feet of gross collection area. The solar hot water heating panels shall have a total solar resource fraction that is not less than 75%.