Minimum Insulation Requirements (Prescriptive/Performance Standards)
|Exterior walls||R-21 cavity plus R-5 continuous or R-20 continuous|
|Rim joist continuous||R-20 cavity plus R-5 continuous or R-20 continuous|
|Floor over exterior/unheated space||R-30 cavity plus R-5 continuous|
|Floor over heated space||R-30 cavity|
|Air tightness||< .20 cfm/ft2 at 50 pascals|
|Window U-value||< .30|
|Window distribution||< 62.5%|
|Maximum window area||Max 18%|
Minimum Equipment Requirements (HVAC)
|Backup gas furnace heating (forced air)||>90% AFUE with ECM|
|Backup gas boiler heating (hot water)||>90% AFUE|
|Electric heating||No requirements|
|Electric cooling (SEER)||>14.5|
|Air-to-air heat exchanger||> 80% HRV or ERV|
|Thermostats for forced air||ENERGY STAR® programmable|
Water Heater Requirements
|Gas instantaneous (tankless)||N/A||any|
|Compliance with Thermal Bypass Checklist||Yes|
|Duct location||Conditioned space only|
|ENERGY STAR® lighting||5 fixtures required|
|ENERGY STAR® dishwasher||Required|
|ENERGY STAR® clothes washer||Required|
|ENERGY STAR® refrigerator||Required|
Prescriptive Standards (R-values listed for insulation only)
Ceiling/Attic (Insulation Only)
- Warm air bypasses (i.e., soil stacks, electrical penetrations, chimney and vent chaseways, etc.) should be sealed to maintain the integrity of the vapor barrier/retarder and to minimize heat loss and condensation in cold attic.
- A solid wind wash barrier shall be provided at the exterior edge of attic insulation to prevent air intrusion into the attic insulation.
Exterior Walls (Insulation Only)
R-21 cavity plus R-5 or R-20 continuous.
Exterior Wind Barrier (House Wrap)
Continuous or sealed wrap applied on the exterior of the structure, extending from bottom of rim joist to the bottom of the exterior soffit. Also, the house wrap should cover all exterior sheathing material and cover cantilevered floors and bay windows. All seams must be taped with a high quality builder tape. The house wrap shall have a perm rating of greater than 1.0.
R-20 cavity plus R-5 continuous or R-20 continuous. Continuous vapor/air barrier sealed in place on all rim joist areas.
Foundation/Basement Wall and Slab on Grade Foundation Wall
Minimum R-20 on entire foundation wall.
Note: All designs need to be engineered to be frost protected.
Slab of Grade
Floating slab R-20 under entire slab and R-20 on slab edge.
Basement Slab or Concrete Floor
Minimum R-20 under entire slab.
Floors Over Exterior/Unheated Space
R-30 plus R-5 continuous (rigid foam). Continuous air barrier required.
Floors Over Heated Space (i.e. heated crawl space and heated garages)
R-30 cavity and continuous air barrier required.
< U .30 (overall unit value). Maximum allowable window area: 18% (total window area to conditioned floor area ratio).
A continuous vapor barrier of less than 1.0 perm rating shall be installed on the winter warm side of exterior walls, ceilings and floors over unconditioned space. All bypasses caused by electrical and plumbing installations must be sealed to maintain the integrity of the vapor barrier. Also, a 6 mil polyethylene or other approved vapor barrier material must be installed under the entire surface area of the slab.
Air Quality Control/Ventilation
The provision of adequate ventilation in residential buildings can only be assured with a central, whole house, pressure balanced, mechanical ventilation system. There is a need to assume a minimum continuous ventilation rate to control the level of indoor air and pollutants generated by occupants or by sources with no fixed or identifiable location. This is accomplished by insuring a minimum level of makeup air. There is also a need to remove some contaminants that are generated at fixed locations, such as kitchens and bathrooms. The minimum rate for whole house ventilation, considering mechanical ventilation capacity and natural air leakage, is .35 ACH. Spot ventilation (kitchen and bathrooms) provided on an intermittent basis must be capable of 100 cfm in the kitchen and 50 cfm in the bathrooms.
Required Ventilation Options: Heat Recovery Ventilator (HRV) or Energy Recovery Ventilator (ERV), also known as air-to-air heat exchangers or whole house mechanical ventilation systems. System balancing is required and an optional incentive is available for the presence of a balancing verification label on the unit.
Minimum apparent sensible effectiveness > 80% at -13°F
Space Heating and Domestic Hot Water
Space Heating: Electric space heating on the firm, dual fuel or storage/off peak rate (i.e., baseboard, slab heat, boiler, furnace, storage units, ground source heat pump, etc.). Ground source heat pumps must be ENERGY STAR® rated as listed at www.energystar.gov.
Backup Gas space heating: Minimum 90% AFUE for furnaces with ECM motors and 90% AFUE for hot water boilers. ENERGY STAR® programmable thermostat required on all gas forced air furnaces. Note: Forced air systems must be fully ducted and no under slab ductwork is allowed. All ductwork must be in conditioned living space.
- Fossil Fuel Appliances: Combustion appliances (i.e., wood, stoves, water heaters) must have an independent source of makeup air directly connected to the combustion chamber (sealed combustion). Houses with wood and corn pellet stoves must meet code requirements.
- Domestic Hot Water: The builder/owner is required to install a high efficiency hot water heater and meet all state requirements for water conservation related to toilets, showerheads and faucet aerators. Also recommended to install pipe wrap insulation on the hot and cold pipes leading to and from the water heater.
ENERGY STAR® Lighting and Appliances
The home must have a minimum of five (5) ENERGY STAR® light fixtures and the refrigerator, dishwasher, and clothes washer must be ENERGY STAR® rated.
Building Orientation (Optional)
Forty percent of glass area must be within 30° south facing for optimum solar gain. This is an optional standard that qualifies for an additional $200 rebate. (Patio and slider doors are considered as window area).
Drain Water Heat Recovery Device (Optional)
A drain water heat recovery device captures heat from the drain water and uses it to preheat incoming cold water. PowerPipe, GFX unit, or equivalent qualifies for an additional $400 rebate. This is an optional standard.