Climate Zones

Climate Zone Maps & Info

Kolbe demonstrates a commitment to providing accurate energy data by having products independently simulated, tested, inspected and listed in the NFRC certification program, and making that data available on our Energy Performance Search page and on window labels.

United States

ENERGY STAR® is a government-regulated program that was created by the Environmental Protection Agency (EPA), and the U.S. Department of Energy (DOE), to help consumers quickly and easily identify energy saving products. The ENERGY STAR program uses energy values obtained by window and door manufacturers through the National Fenestration Rating Council (NFRC) program. NFRC ratings are based on the energy performance of the total window or door – both glass and frame

The ENERGY STAR program for the United States divides the nation into four separate climate zones – Northern, North-Central, South-Central, and Southern. The performance criteria that needs to be met in order to be ENERGY STAR compliant in specific climate zones are shown in the charts provided. Note that this information is per criteria that took effect in 2023.

California's Title 24

Kolbe has windows and doors that can meet the strict California Title 24 Building Energy Efficiency Standards. Contact us or talk to your dealer about our products with glass options that help meet these stringent energy efficiency requirements.
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2023 ENERGY STAR – Qualification Criteria for Windows*

Northern** ≤ 0.22 ≥ 0.17
Northern** = 0.23 ≥ 0.35
Northern** = 0.24 ≥ 0.35
Northern** = 0.25 ≥ 0.40
Northern** = 0.26 ≥ 0.40
North-Central ≤ 0.25 ≤ 0.40
South-Central ≤ 0.28 ≤ 0.23
Southern ≤ 0.32 ≤ 0.23

*The effective date for the Northern Zone prescriptive and equivalent energy performance criteria for windows was September 7, 2023. North-Central, South-Central, and Southern criteria will also follow 2023 guidelines.

**Northern zone windows can meet prescriptive (1st row) or alternative energy performance (2nd, 3rd, and 4th rows) criteria to qualify for ENERGY STAR.

2023 ENERGY STAR – Qualification Criteria for Doors

Opaque ≤  0.17 No rating
≤  1/2-Lite ≤ 0.23 ≤  0.23
> 1/2-Lite ≤  0.26 Northern and North-Central   ≤ 0.40
> 1/2-Lite ≤  0.28 Southern and South-Central   ≤ 0.23


Fenestration products may comply for Canada's ENERGY STAR program based on these compliance paths: their total U-factor, their Energy Rating (ER), or both. The Energy Rating is based on a product's overall performance based on three criteria: (1) Solar heat gain​, (2) U-factor, and (3) Average air tightness. The higher the ER number, the better the product's thermal performance. 

The U-factor and ER criteria for Canada is shown in the chart provided. For Kolbe products that qualify for Canada's ENERGY STAR Program, search their site using the Related Links below.


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2020 ENERGY STAR – Qualification Criteria for Windows & Doors in Canada*

34 or ≤ 0.21

*Criteria shown applies to windows, sliding doors, and swinging doors

U-Factor Equivalency – Qualification Criteria for Windows & Doors in Canada*

0.35 2.00
0.32 1.80
0.28 1.60
0.25 1.40
0.21 1.20
Related Links: ENERGY STAR qualified products in Canada: Windows | Doors | Door Sidelites & Transoms

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