United States

International Energy Conservation Code (IECC 2009) - Residential

The International Energy Conservation Code (IECC) is a model code that regulates minimum energy conservation requirements for new buildings. The IECC addresses energy conservation requirements for all aspects of energy uses in both commercial and residential construction, including heating and ventilating, lighting, water heating, and power usage for appliances and building systems. (source: 2009 IECC)

Applicable Building Type(s)

New residential

Policy Requirement Level

Model Code

Policy Sequence

Governance

Development Authority: International Code Council

Implementation Authority: Local authorities

Prescriptive Compliance path

Occupiable space, excluding crawl spaces and garages

Energy Requirements:

Insulation

U-Values (Btu/h.ft2)FloorRoofWalls
Climate zone 1 0.064 0.035 0.197
Climate zone 2 0.064 0.035 0.165
Climate zone 3A and 3B 0.047 0.035 0.141
Climate zone 4A and 4B 0.047 0.03 0.141
Climate zone 4C 0.033 0.03 0.082
Climate zone 5 0.033 0.03 0.082
Climate zone 6 0.033 0.026 0.06
Climate zone 7 0.033 0.026 0.057
Climate zone 8 0.028 0.026 0.057

Windows

U-Values (Btu/h.ft2)Windows
Climate zone 1 1.2
Climate zone 2 0.65
Climate zone 3A and 3B 0.5
Climate zone 4A and 4B 0.35
Climate zone 4C 0.35
Climate zone 5 0.35
Climate zone 6 0.35
Climate zone 7 0.35
Climate zone 8 0.35

The total glazed area may not exceed 18% of the conditioned floor area using the prescriptive method

SHGC (for all fenestration including skylights) is 0.30 W/m2.k for climate zones 1-3. No SHGC requirement for other zones

Skylights

Skylights individually are 0.75 W/m2.k zones 1-2, 0.65 W/m2.k zone 3 and 0.60 W/m2.k zones 4-8

Air Leakage

7 ACH at 50Pa. The thermal envelope must be verified even when using the perscriptive method

Space Heating System

At least one thermostat shall be provided for each separate heating and cooling system.

Specific requirements exist for ducts, piping, ventilation, pool systems and snow melt systems

Requirements are relative to equipment size and building type.

Water Heating System

All circulating service hot water piping shall be insulated to at least R-2 and have automatic or accessible manual switches to turn off the pump when the system is not in use

Lighting

A minimum 50% of lamps in permanently installed lighting fixtures shall be high-efficacy lamps.

Renewable Energy

Pools deriving >60% heating energy from site-recovered or solar energy are exempt from pool specific energy saving measures

End-uses considered:

Space cooling, Space heating, Water heating, Ventilation, Lighting interior, Lighting exterior

Performance Compliance path

Not a requirement / performance based elements are based on a reference model and are relative to energy costs

Energy Requirements:

End-uses considered:

Water heating, Ventilation, Space heating, Space cooling, Lighting interior, Equipment

Resources

Notes

Climate zones

ZONE 
NUMBER
THERMAL CRITERIA
IP Units
SI Units
1
9000 < CDD50°F 5000 < CDD10°C
2
6300 < CDD50°F ≤ 9000 3500 < CDD10°C ≤ 5000
3A and 3B
4500 < CDD50°F ≤ 6300
AND HDD65°F ≤ 5400
2500 < CDD10°C ≤ 3500
AND HDD18°C ≤ 3000
4A and 4B
CDD50°F ≤ 4500 AND
HDD65°F ≤ 5400
CDD10°C ≤ 2500 AND
HDD18°C ≤ 3000
3C
HDD65°F ≤ 3600 HDD18°C ≤ 2000
4C
3600 < HDD65°F ≤ 5400 2000 < HDD18°C ≤ 3000
5
5400 < HDD65°F ≤ 7200 3000 < HDD18°C ≤4000
6
7200 < HDD65°F ≤ 9000 4000 < HDD18°C ≤ 5000
7
9000 < HDD65°F ≤ 12600 5000 < HDD18°C ≤ 7000
8
12600 < HDD65°F 7000 < HDD18 °C