PRESCRIPTIVE STANDARDS
(R-values listed for insulation only)
(> means equal to or greater than. < means equal to or less than)

1. Foundation/Basement Wall and Slab on Grade Foundation Wall:
Minimum R-15 to footings. Insulation must extend to top of foundation wall and be securely attached. Required protection of exterior foam from sunlight and physical abuse and the installation of drainage materials along exterior walls to keep water away from the foundation.
Tier II: Minimum R-20 on entire foundation wall.

2. Slab on Grade: Floating slab R-15 under entire slab and R-15 on slab edge. Note: all designs need to be engineered to be frost protected.
Tier II: Floating slab R-20 under entire slab and R-20 on slab edge..

3. Basement slab or concrete floor: Minimum R-15 under entire slab. Continuous vapor barrier/retarder under entire slab for moisture and radon control.
Tier II: Minimum R-20 under entire slab.

4. Floors over exterior/unheated space: R-24 plus R-5 continuous (rigid foam). Continuous air barrier required.
Tier II: R-30 plus R-5 continuous (rigid foam). Continuous air barrier required.

Floors over heated space (i.e., heated crawl space and heated garage): R-24 cavity and continuous air barrier required.
Tier II: R-30 cavity and continuous air barrier required.

5. Exterior Walls (insulation only): minimum R-21 cavity.
Tier II: R-21 cavity plus R-5 or R-20 continuous.

6. 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.

7. Ceiling/Attic (insulation only): minimum R-50 blown (insulation only) – (must meet winter design performance criteria as specified by Minnesota State Energy Code) with energy truss or raised heel.
Tier II: R-60 blown

a. 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.
b. A solid wind wash barrier shall be provided at the exterior edge of attic insulation to prevent air intrusion into the attic insulation.

8. Rim Joist: minimum R-20 cavity or R-15 continuous. Continuous interior/warm side vapor/air barrier sealed in place on all rim joist areas
Tier II: R-20 cavity plus R-5 continuous or R-20 continuous. Continuous vapor/air barrier sealed in place on all rim joist areas.

9. Windows: Minimum standards < U .33 (overall unit value)
Tier II: < U .30 (overall unit value) Maximum allowable window area: 18% (total window area to conditioned floor area ratio)

10. Moisture Control: 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. Appendix 5 lists the perm rating of common building materials.

11. 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.

11.1 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.
Tier I: Minimum apparent sensible effectiveness ≥ 76% at -13°F (see Appendix 4 listing minimum requirements for ventilation systems.)
Tier II: Minimum apparent sensible effectiveness ≥ 80% at -13°F. (see Appendix 4 listing minimum requirements for ventilation systems.)

12. Space Heating and Domestic Hot Water

12.1 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.

Tier I: Ductwork located in unconditioned spaces require thorough sealing of all seams and joints with jacketed insulation to a minimum of R-8.

Tier II: All ductwork must be in conditioned living space.

12.2 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 stover or corn pellet stoves must meet code requirements.

12.3 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.
Tier II: (see Appendix 1 for water heater efficiency requirements)

13. 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.

14. Building Orientation (optional)

Forty percent of glass area must be within 30 degrees 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)

15. 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.

TRIPLE E PERFORMANCE STANDARDS

1. Air Tightness Performance Standard

Minimum air leakage not to exceed .25 cfm/ft2 at 50 pascals. Tier II: not to exceed .20 cfm/ft2 at 50 pascals. Note: Achieving air tightness levels of .10 cfm/ft2 at 50 pascals (eligible for additional rebate incentive)

Blower door analysis (depressurization technique) is completed during the final inspection.