D.C. Mun. Regs. tit. 12, 12-I402
Strike Section R402.1 of the International Energy Conservation Code in its entirety and insert new Section R402.1 in the Energy Conservation Code-Residential Provisions in its place to read as follows:
The building thermal envelope shall meet the requirements of Sections R402.1.2 through R402.1.5.
Exception: The following low-energy buildings, or portions thereof, separated from the remainder of the building by building thermal envelope assemblies complying with this section shall be exempt from the building thermal envelope provisions of Section R402.
Strike Section R402.1.1 of the International Energy Conservation Code in its entirety without substitution.
Strike Section R402.1.2 of the International Energy Conservation Code in its entirety and insert new section R402.1.2 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
Insulation and fenestration criteria. The building thermal envelope shall meet the requirements of Table R402.1.2.
Strike Table R402.1.2 of the International Energy Conservation Code in its entirety and insert new Table R402.1.2 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
TABLE R402.1.2 INSULATION AND FENESTRATION REQUIREMENTS BY COMPONENTa
FENESTRATION U-FACTORb | 0.30 U-Factor |
SKYLIGHTb U-FACTOR | 0.55 U-Factor |
GLAZED FENESTRATION SHGCb | 0.40 Solar Heat Gain Coefficient (SHGC) |
CEILING | R-49 |
WOOD FRAME WALL AND RIM JOISTS | R-19 in cavity + R-5 continuous on the exterior, or R-13 in cavity + R-10 continuous on the exterior, or R-15 continuous |
MASS WALLi | R-15 continuous on the exterior, or R-20 continuous on the interior |
FRAME FLOOR | R-25 + R-5 continuous |
ELEVATED SLAB | R-15 continuous |
BASEMENT WALL | R-19 cavity + R-5 continuous on the exterior, or R-13 in cavity + R-10 continuous on the exterior, or R-15 continuous |
SLAB ON GRADEd | R-10 perimeter insulation for a depth of 2 ft |
CONDITIONED CRAWLSPACE WALL | R-19 cavity + R-5 continuous on the exterior, or R-13 in cavity + R-10 continuous on the exterior, or R-15 continuous |
For SI: 1 foot = 304.8 mm.
R-value computation. (no change)
U-factor alternative.
Strike Table R402.1.4 of the International Energy Conservation Code in its entirety and insert new Table R402.1.4 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
TABLE R402.1.4 EQUIVALENT U-FACTORSa
FENESTRATION U-FACTOR | 0.30 U-Factor |
SKYLIGHT U-FACTOR | 0.55 U-Factor |
CEILING U-FACTOR | 0.026 U-Factor |
WOOD FRAME WALL U-FACTOR | 0.045 U-Factor |
MASS WALL U-FACTOR | 0.060 U-Factor |
FRAME FLOOR U-FACTOR | 0.033 U-Factor |
ELEVATED SLAB | 0.066 U-Factor |
MASS FLOOR U-FACTOR | 0.058 U-Factor |
BASEMENT WALL U-FACTOR | 0.045 U-Factor |
CONDITIONED CRAWLSPACE WALL U-FACTOR | 0.045 U-Factor |
Total UA alternative. (no change)
Strike Section R402.2.1 of the International Energy Conservation Code in its entirety and insert new section R402.2.1 in the Energy Conservation Code in its place to read as follows.
Ceilings with attic spaces. Where Section R402.1.2 would require R-49 insulation in the ceiling but the depth of the roof rafters does not allow R49, the ceiling insulation value may be
reduced to R-38. This reduction shall not apply to the U-factor alternative approach in Section R402.1.4 and the total UA alternative in Section R402.1.5.
Strike Section R402.2.2 of the International Energy Conservation Code in its entirety without substitution.
Strike Section R402.2.3 of the International Energy Conservation Code in its entirety and insert new section R402.2.3 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
Eave baffle. For air-permeable insulation in vented attics utilizing eave vents, a baffle shall be installed adjacent to soffit and eave vents. Baffles shall maintain an opening equal or greater than the size of the vent. The baffle shall extend over the top of the attic insulation. The baffle may be any solid material.
Strike Section R402.2.4 of the International Energy Conservation Code in its entirety and insert new Section R402.2.4 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
Access hatches and doors. Access doors from conditioned spaces to unconditioned spaces such as attics and crawl spaces shall be weather stripped and insulated to a level equivalent to the insulation on the surrounding surfaces. Access shall be provided to all equipment that prevents damaging or compressing the insulation. A wood-framed or equivalent baffle or retainer is required to be provided when loose-fill insulation is installed, the purpose of which is to prevent the loose-fill insulation from spilling into the living space when the attic access is opened, and to provide a permanent means of maintaining the installed R-value of the loose-fill insulation.
Exception: Vertical doors that provide access from conditioned to unconditioned spaces shall be permitted to meet the fenestration requirements of Table R402.1.2.
Strike Table R402.2.6 of the International Energy Conservation Code in its entirety and insert new Table R402.2.6 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
TABLE R402.2.6 STEEL-FRAME CEILING,WALLANDFLOORINSULATION
(R-VALUE)
WOOD FRAME R-VALUE REQUIREMENT | COLD-FORMED STEEL a EQUIVALENT R-VALUE |
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" on center | |
R-13 | R-13 + 4.2 or R-19 + 2.1 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-19 + 5 | R-15 continuous or R-13 + 12.2 or R-15 + 11.8 or R-19 + 11.2 or R-21 + 10.9 or R-25 + 10.5 |
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" 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-19 + 5 | R-15 continuous or R-13 + 11.1 or R-15 + 10.4 or R-19 + 9.7 or R-21 + 9.2 or R-25 + 8.7 |
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 |
R-25 + 5 | R-15 + 15 |
Insulation exceeding the height of the framing shall cover the framing.
Strike Section R402.2.9 of the International Energy Conservation Code in its entirety without substitution.
Strike Section R402.2.10 of the International Energy Conservation Code in its entirety and insert new Section R402.2.10 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
Slab-on-grade floors. Slab-on-grade floors with a floor surface less than 30 inches (762 mm) below grade shall be insulated in accordance with Table R402.1.2. The insulation shall extend downward from the top of the slab on the outside or inside of the foundation wall. Insulation located below grade shall be extended the distance provided in Table R402.1.2 by any combination of vertical insulation, insulation extending under the slab or insulation extending out from the building. Insulation extending away from the building shall be protected by pavement or by not less than 10 inches (254 mm) of soil. The top edge of the insulation installed between the exterior wall and the edge of the interior slab shall be permitted to be cut at a 45-degree (0.79 rad) angle away from the exterior wall. Slab-edge insulation is not required in jurisdictions designated by the code official as having a very heavy termite infestation.
Strike Section R402.2.11 of the International Energy Conservation Code in its entirety and insert new Section R402.2.11 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
Crawl space walls. As an alternative to insulating floors over crawl spaces, crawl space walls may be insulated when the crawl space is not vented to the outside. Crawl space wall insulation shall be permanently fastened to the wall and extend downward from the underside of the floor, including the band joist area, to the finished grade level and then vertically and/or horizontally for at least an additional 24 inches (610 mm). Exposed earth in unvented crawl space foundations shall be covered with a continuous Class I vapor retarder in accordance with the Building Code or Residential Code, as applicable. All joints of the vapor retarder shall overlap by 6 inches (153 mm) and be sealed or taped. The edges of the vapor retarder shall extend not less than 6 inches (153 mm) up the stem wall and shall be attached to the stem wall.
Strike Section R402.2.13 of the International Energy Conservation Code in its entirety and insert new Section R402.2.13 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
Sunroom insulation.Sunrooms enclosing conditioned space shall meet the insulation requirements of this code.
Strike Section R402.3.5 of the International Energy Conservation Code in its entirety and insert new Section R402.3.5 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
Sunroom fenestration.Sunrooms enclosing conditioned space shall meet the fenestration requirements of this code.
Strike Table R402.4.1.1 of the International Energy Conservation Code in its entirety and insert new Table R402.4.1.1 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
TABLE R402.4.1.1 AIR BARRIER AND INSULATION INSTALLATION
COMPONENT | AIR BARRIER CRITERIA | INSULATION INSTALLATION CRITERIA |
General requirements | A continuous six-sided 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. All ceiling, wall, floor and slab insulation shall achieve Grade I installation per the RESNET Standards or, alternatively, Grade II for surfaces that contain a layer of continuous, air impermeable insulation > R5. |
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 downstairs 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 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 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. Doors adjacent to unconditioned space or ambient conditions shall be made substantially air-tight with weather stripping or equivalent gasket. | Continuous exterior insulation shall continue over window and door headers. Skylight and window chases through unconditioned attic space must be insulated to exterior wall values per table 402.1.2. |
Rim joists | Rim joists shall include continuous air barrier. | Rim joists shall be insulated per Table 402.1.2. |
Floors (including above garage and cantilevered floors) | The air barrier shall be installed at any exposed edge of insulation. | 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 opening to exterior or unconditioned space shall be sealed. | Duct shafts or chases next to exterior or unconditioned space shall be insulated. |
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. | Walls next to unconditioned garage space shall be insulated. |
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 | Seal any plumbing or wiring that penetrates the building envelope. | 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. | |
Common wall separating dwelling units | Air barrier is installed in common wall between dwelling units. | |
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. | |
Fireplace | An air barrier shall be installed on fireplace walls. |
In addition, inspection of log walls shall be in accordance with the provisions of ICC-400.
Strike Section R402.4.1.2 of the International Energy Conservation Code in its entirety and insert new Section R402.4.1.2 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
Air Leakage Testing. Each dwelling unit shall comply with Table R402.4.1.2. 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). Testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the approved third party conducting the test and provided to the code official before issuance of the certificate of occupancy or final inspection. Testing shall be performed at any time after creation of all penetrations of the building thermal envelope. Approved sampling protocols approved by the code official may be used.
Insert new Table R402.4.1.2 in the Energy Conservation Code-Residential Provisions to read as follows.
TABLE R402.4.1.2 MAXIMUM ALLOWED AIR LEAKAGE RATES
New construction | Level 3 Alteration affecting 80% or more of the aggregate work of the building (Gut Rehabilitation) | |
Single family detached, two family attached (duplex), townhouses, flats | 3 ACH50 | 3 ACH50 |
Dwelling units in Multifamily buildings 3 stories and less | .30 CFM50/SF enclosure area of each unit or 3 ACH50 | .30 CFM50/SF enclosure area of each unit or 3 ACH50 |
Strike Section R402.4.4 of the International Energy Conservation Code in its entirety and insert new Section R402.4.4 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
For new construction, all new fuel burning appliances and equipment located inside the building envelope must be sealed combustion.
Existing buildings undertaking a Level 3 alteration at 80% of aggregate area must comply with one of the following:
In an existing building Level 3 alteration at 80% of aggregate area that contains open combustion equipment or appliances, a "worst-case testing of atmospheric venting systems" shall be conducted by an approved party in accordance with Appendix RA. Testing reports shall be provided to the
code official. If the building fails the test in accordance with Appendix RA, the existing equipment must comply with either option 1 or 2.
Exceptions:
Strike Section R402.5 of the International Energy Conservation Code in its entirety and insert new Section R402.5 in the Energy Conservation Code-Residential Provisions in its place to read as follows.
The area-weighted average maximum fenestration U -factor permitted using tradeoffs from Section R402.1.5 or R406 shall be 0.40 for vertical fenestration, and 0.75 for skylights.
Insert new Sections R402.6 and R402.6.1 in the Energy Conservation Code-Residential Provisions to read as follows.
Roof coverings for roof slopes less than or equal to two units vertical in 12 units horizontal (17 percent slope or less) for buildings and covered parking shall conform to this section. A minimum of 75 percent of the entire roof surface not used for roof penetrations, renewable energy power systems (e.g., photovoltaics or solar thermal collectors), harvesting systems for rainwater to be used on-site, or green roofing systems shall be covered with products that comply with one or both of the following:
Exceptions:
Initial and aged values of the SRI shall be calculated in accordance with ASTM E1980 for medium-speed wind conditions, using a convection coefficient of [2.1 BTU/(h ft2 °F)] or the metric equivalent [12 W/(m2 . K)]. The SRI shall be based upon solar reflectance as measured in accordance with ASTM E1918 or ASTM C1549, and the thermal emittance as measured in accordance with ASTM E408 or ASTM C1371. For roofing products, the values for solar reflectance and thermal emittance shall be determined by a laboratory accredited by a nationally recognized accreditation organization, such as the Cool Roof Rating Council CRRC-1 Product Rating Program, and shall be labeled and certified by the manufacturer.
D.C. Mun. Regs. tit. 12, 12-I402