2015 Residential IECC Significant Changes Eric Makela, Cadmus 1
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Space Conditioning Any non ‐ conditioned space that is altered to Examples: become • Converting a garage conditioned space to a family room shall be required • Heating a basement to be brought into full compliance with this code 3
Chapters in the IRC that Impact Energy Usage Chapter 5 Chapter 6 •Frost protected •Advanced wall framing shallow foundations Chapter 4 •Foundation water and damp ‐ proofing; •Foundation venting Chapter 3 •Insulation installation •Glazing types 4
Chapters in the IRC that Impact Energy Usage (cont’d) Chapter 14 Chapter 16 •Heating and cooling •Duct sizing and design sizing calculation requirements Chapter 8 •Weather resistant roof assemblies; Conditioned attic assemblies Chapter 7 •Weather resistant coverings for walls 5
Overview of Residential Code Requirements Sets insulation and Ceilings, walls, Infiltration control ‐ Focus is on building fenestration levels, windows, floors, caulk and seal to envelope and solar heat gain foundations prevent air leaks coefficients Ducts – seal and insulate Limited space heating, air Federal law sets most equipment efficiency conditioning, and requirements, water heating not the I ‐ codes requirements No appliance requirements Lighting equipment – 75% of lamps to be 6 high ‐ efficacy lamps
Building Envelope 7
Building Envelope Specific Requirements Building Envelope consists of: • Ceilings • Walls • Above grade attic • Below grade • Mass walls • Fenestration • Floors Conditioned Space • Slab • Crawl space 8
Table R402.1.2 Insulation and Fenestration Requirements by Component Climate Fenestration Skylight Glazed Ceiling Wood Mass Floor Basement Slab Crawl Zone U ‐ Factor U ‐ Factor Fenestration R ‐ Frame Wall R ‐ R ‐ Value R ‐ Space SHGC Value Wall R ‐ Value Value Value Wall R ‐ R ‐ Value Value 20 or 3 0.35 0.55 0.25 38 8/13 19 5/13 0 5/13 13+5 5 & 20 or 10, Marine 0.32 0.55 NR 49 13/17 30 15/19 15/19 13+5 2ft 4 9
Floors over Unconditioned Space Insulation must maintain permanent contact with underside of subfloor Unconditioned space includes unheated basement, vented crawlspace, or outdoor air Exception: Climate Zones R ‐ Value Climate Zones 4c ‐ 8 1 ‐ 2 13 R ‐ 19 permitted if 3 ‐ 4 a,b 19 cavity completely filled 4c ‐ 6 30 7 ‐ 8 38 10
Slab Edge Insulation Applies to slabs with a floor surface < 12 inches below grade An additional R ‐ 5 is required for heated An additional R ‐ 5 is slabs Insulation extending required for heated Insulation extending outward must be slabs outward must be under 10 inches of under 10 inches of soil or pavement soil or pavement Insulation can be vertical or extend horizontally under the slab or out from Insulating depth of the building Insulation depth of the footing or 2 feet, the footing or 2 feet, whichever is less in whichever is less in Must extend Zones 1 ‐ 3 for heated Zones 1 ‐ 3 for heated downward from top Must extend slabs slabs of slab a minimum of downward from top R ‐ 10 (typically 2 24” (Zones 4 and 5) of slab a minimum of inches) insulation in R ‐ 10 (typically 2 or 48” (Zones 6, 7, 24” (Zones 4 and 5) Zones 4 and above inches) insulation in and 8) or 48” (Zones 6, 7, Zones 4 and above and 8) 11
Vented and Unvented Crawlspace Vented Crawlspace Requirements: •The raised floor over the crawlspace must be insulated. •A vapor retarder may be required as part of the floor assembly. •Ventilation openings must exist that are equal to at least 1 square foot for each 150 square feet of crawlspace area and be placed to provide cross ‐ flow (IRC 408.1, may be less if ground vapor retarder is installed). •Ducts in crawlspace must be sealed and have R ‐ 6 insulation. •The raised floor over the crawlspace must be insulated. •A vapor retarder may be required as part of the floor assembly. •Ventilation openings must exist that are equal to at least 1 square foot for each 150 square feet of crawlspace area and be placed to provide cross ‐ flow (IRC 408.1, may be less if ground vapor retarder is installed). •Ducts in crawlspace must be sealed and have R ‐ 6 insulation. Unvented Crawlspace Requirements: •The crawlspace ground surface must be covered with an approved vapor retarder (e.g., plastic sheeting). •Crawlspace walls must be insulated to the R ‐ value requirements specific for crawlspace walls (IECC Table 402.1.1). •Crawlspace wall insulation must extend from the top of the wall to the inside finished grade and then 24” vertically or horizontally. •Crawlspaces must be mechanically vented (1 cfm exhaust per 50 square feet) or conditioned (heated and cooled as part of the building envelope). •Ducts are inside conditioned space and therefore don’t need to be insulated. 12
Defining Below ‐ Grade Walls 13
Below ‐ Grade Walls Insulated from top of basement wall down to 10 ft below grade or basement floor, whichever is less Climate Zones R-Value 1-2 0 3 5/13 4 10/13 5-8 15/19 ≥ 50% below grade Otherwise treat as above ‐ grade wall 14
Walls Covered by IECC 15
Wood Frame Walls Table 402.1.1 Insulation and Fenestration Requirements by Component Climate Fenestration Skylight Glazed Ceiling Wood Frame Mass Wall Floor Zone U ‐ Factor U ‐ Factor Fenestration R ‐ Value Wall R ‐ Value R ‐ Value R ‐ Value Required R-value can be met with 1 13 3 / 4 13 any combination of cavity or 2 13 4/6 13 continuous insulation 3 20 or 13 + 5 5/8 19 Exception in zones 5-6: R-13 cavity 4 plus R-5 sheathing meets R-20 except 20 or 13 + 5 5/10 19 requirement Marine 5 & Marine 0.35 0.60 NR 38 20 or 13 + 5 13/17 30 4 20 + 5 or 6 0.35 0.60 NR 49 15/19 30 13 + 10 20 + 5 or 7 and 8 0.35 0.60 NR 49 19/21 38 13 + 10 16
Mass Wall Requirements Table 402.1.1 Insulation and Fenestration Requirements by Component Climate Fenestration Skylight Glazed Ceiling Wood Frame Mass Wall Floor Zone U ‐ Factor U ‐ Factor Fenestration R ‐ Value Wall R ‐ Value R ‐ Value R ‐ Value Second (higher) number applies 1 13 3 / 4 13 when more than half the R-Value is 2 13 4/6 13 on the interior of the mass (i.e., when the thermal mass is insulated 3 20 or 13 + 5 5/8 19 from the conditioned space 4 except 20 or 13 + 5 5/10 19 Marine 5 & Marine 0.35 0.60 NR 38 20 or 13 + 5 13/17 30 4 20 + 5 or 6 0.35 0.60 NR 49 15/19 30 13 + 10 20 + 5 or 7 and 8 0.35 0.60 NR 49 19/21 38 13 + 10 17
Fenestration • Climate Zone 3 U ‐ Factor – 0.35 • Climate Zone 5 & Marine 4 U ‐ Factor – 0.32 Doors • No glass area limits • Exemptions (prescriptive path only) and • Up to 15 ft 2 of glazing per dwelling unit (Section 402.3.3) Windows • One side ‐ hinged opaque door assembly up to 24 ft 2 (Section 402.3.4) 18
Ceilings Requirements based on •Assembly type •Continuous insulation •Insulation between framing (cavity insulation) Climate Zone R ‐ Value Meet or 1 30 exceed R ‐ values 2 – 3 38 4 ‐ 9 49 19
Ceilings without Attics (e.g., vaulted) • Where Insulation levels are required > R ‐ 30 • Not sufficient amount of space to meet higher levels • R ‐ 30 allowed for 500 ft 2 or 20% total insulated ceiling area, whichever is less 20
Ceilings with Attics R ‐ 30 Note: This allowance ONLY complies applies to the where R ‐ 38 R ‐ value is required prescriptive path, not the • R ‐ 38 complies U ‐ factor or Total where R ‐ 49 is If insulation is UA alternatives required full height over exterior wall top plate Prescriptive R ‐ value path encourages raised heel truss (aka, energy truss ) 21
Mandatory Requirements – Air Leakage • Building thermal envelope – (Section 402.4) • Recessed lighting • Fenestration • Fireplaces 22
Air Sealing and Insulation Compliance Requirements for Climate Zones 3 to 8 Whole ‐ house pressure test Whole ‐ house pressure test • Air leakage ≤ 3 ACH when tested at pressure • Air leakage ≤ 3 ACH when tested at pressure differential of 0.2 inches w.c. differential of 0.2 inches w.c. Testing may occur any time after rough in and Testing may occur any time after rough in and installation of building envelope penetrations installation of building envelope penetrations Field verification of items listed in Table Field verification of items listed in Table 402.4.1.1 402.4.1.1 23
Table R402.4.1.1 Air Barrier and Insulation Installation • Reformatted table to increase usability 24
Controls Heat pump Pools supplemen tary heat Mandatory Ducts Snow melt controls •Sealing Requirements (Mandatory) •Insulation Systems (Prescriptive) Systems (Section 403) serving multiple dwelling HVAC units piping insulation Circulating Equipment hot water sizing systems Ventilation 25
Programmable Thermostat ‐ Controls • At least one programmable thermostat per dwelling unit • Capability to set back or temporarily operate the system to maintain zone temperatures • down to 55ºF (13ºC) or • up to 85ºF (29ºC) • Initially programmed with: • heating temperature set point no higher than 70ºF (21ºC) and • cooling temperature set point no lower than 78ºF (26ºC) If primary heating system is a forced ‐ air furnace 26
Heat Pump Supplementary Heat ‐ Control Prevent supplementary electric ‐ Exception resistance heat • During defrost when heat pump can meet the heating load 27
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