Section 12-I4-RE02. R402 - BUILDING THERMAL ENVELOPE

Strike Section R402.2.9 in the International Energy Conservation Code in its entirety and insert new Section R402.2.9 in the Energy Conservation Code in its place to read as follows:

R402.2.9. Slab-on-grade floors.  Slab-on-grade floors shall be insulated in accordance with Table R402.1.1.  Under-slab insulation is required for heated slabs on grade and shall be placed immediately below required vapor retarders.  The perimeter insulation shall extend downward from the top of the slab surface on the outside or inside of the foundation wall.  Perimeter insulation located below grade shall be extended the distance provided in Table R402.1.1 by any combination of vertical insulation, insulation extending under the slab or insulation extending out from the building foundation.  Perimeter insulation extending away from the building foundation shall be protected by pavement or by a minimum of 10 inches (254 mm) of soil cover.  The top edge of the insulation installed between the exterior wall and the edge of the interior slab-on-grade shall be permitted to be cut at a 45-degree (0.79 rad) angle away from the exterior wall.  Slab-edge insulation shall not be required where the code official designates the District of Columbia as having a very heavy termite infestation.

 

Exception:  Where the unheated slab-on-grade floor is greater than 12 inches (305 mm) below the finished exterior grade, perimeter insulation is not required. 

Strike Section R402.4.1 of the International Energy Conservation Code in its entirety and insert new Section R402.4.1 in the Energy Conservation Code in its place to read as follows:

 

R402.4.1 Building thermal envelope. The building thermal envelope of (1) detached one- and two-family dwellings and townhouses; (2) Group R-3 buildings and (3) their accessory structures shall comply with Sections R402.4.1.1 and R402.4.1.2.  The building thermal envelope of Group R-2 and R-4 buildings three stories or less in height above grade plane shall comply with either Sections R402.4.1.1 or 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 of less than or equal to 5 air changes per hour at a pressure of 0.2 inches w.g. (50 Pascals).  Testing shall be conducted with a blower door at a pressure of 0.2 inches 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.  Testing shall be conducted in accordance with a method approved by the code official including, but not limited to, an approved sampling protocol.

 

Exception:  Additions, alterations, renovations or repairs are not subject to the testing requirements under R402.4.1.2 except for Level 3 alterations.  However, the air barrier and insulation installation for additions, alterations, renovations or repairs shall be completed in accordance with Table R402.4.1.1 as applicable to the scope of work.

 

During testing:

 

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

 

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

 

Strike Table R402.4.1.1 in the International Energy Conservation Code in its entirety and insert new Table R402.4.1.1 in the Energy Conservation Code in its place to read as follows:

TABLE R402.4.1.1

AIR BARRIER AND INSULATION INSTALLATION

 

COMPONENT		AIR BARRIER CRITERIA a	INSULATION INSTALLATION CRITERIA
General Requirements		A continuous air barrier shall be installed in the building envelope. Exterior thermal envelope shall contain 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 sealed. Access openings, drop down stair 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		Junctions of the foundation and sill plate shall be sealed. Junctions of the top plate and top of exterior walls shall be sealed. Knee walls shall be sealed.	Corners and headers shall be insulated. 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.	Insulation shall be installed to maintain permanent contact with underside of subfloor decking.
COMPONENT		AIR BARRIER CRITERIA a	INSULATION INSTALLATION CRITERIA
Crawl space walls		Exposed earth in unvented crawl spaces shall be covered with a Class I vapor retarder with overlapping joints taped.	Where provided in lieu 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.
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, 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.

COMPONENT	AIR BARRIER CRITERIA a	INSULATION INSTALLATION CRITERIA
Electrical / phone box on exterior walls	The air barrier shall be installed behind electrical or communication boxes, or air sealed boxes shall be installed.
HVAC register boots	HVAC register boots that penetrate building thermal envelope shall be sealed to the subfloor or drywall.
Fireplace	An air barrier shall be installed on fireplace walls. Fireplaces shall have gasketed doors

1.  In addition, inspection of log walls shall be in accordance with the provisions of ICC-400

 

 

authority

Section 10 of the Construction Codes Approval and Amendments Act of 1986 (Act), effective March 21, 1987 (D.C. Law 6-216; D.C. Official Code § 6-1409 (2012 Repl.)) and Mayor’s Order 2009-22, dated February 25, 2009, as amended.

source

Final Rulemaking published at 61 DCR 3322 (March 28, 2014 – Part 2).

EditorNote

The District of Columbia Energy Conservation Code (2013), referred to as the “Energy Conservation Code,” consists of the 2012 edition of the International Energy Conservation Code, published by the International Code Council, as amended by the District of Columbia Energy Conservation Code Supplement (2013)(12 DCMR I). The International Energy Conservation Code is copyrighted by the ICC and therefore is not republished here. However, a copy of the text may be obtained at: http://publicecodes.cyberregs.com/icod/iecc/2012/index.htm?bu=IC-P-2012-000014&bu2=IC-P-2012-000019.