Energy Efficient Windows

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If you’re dealing with poor window performance, such as drafty windows, temporary solutions like sealants and weatherstripping won’t keep your home comfortable for long. Replacement windows from Great Lakes Window will seal out unwanted cold and heat, saving you a bundle on heating and cooling costs. So while Mother Nature stays out, energy efficient windows keep you safe and sound all year-round. Our windows are built to resist the heat and cold, offering four-season comfort. Need proof? We meet or exceed the current standards for ENERGY STAR® Version 6.0 requirements in all 50 states and can exceed requirements for the Northern Zone, by up to 48% with select glass packages. Below are four common ratings that are provided for windows certified by the National Fenestration Rating Council (NFRC), the American National Standards Institute (ANSI) and the American Architectural Manufacturers Association (AAMA).  

Defining Energy Performance Ratings: window energy performance ratings

  • U-Factor – A measure of the rate of heat flow through a window. Heat efficient windows have better insulating properties. A lower U-Factor indicates a higher performing window that can help reduce heating and cooling costs.
  • Solar Heat Gain Coefficient (SHGC) – The amount of solar radiation allowed to pass through a window. The lower the number, the less solar heat gain the window permits.
  • Structural-Design Pressure (DP) – The amount of wind pressure a window will withstand when closed and locked is called Structural-Design Pressure (DP). The higher the number, the better.
  • Visible Light Transmittance – Ranging from 0 – 1, visible transmittance is a measure of how much light passes through the window.
The Windows look great and we can see the a/c and heating savings already. We highly recommend this company. – Barbara Maher
In 2016, ENERGY STAR changed their ratings dictating what U-Values and Solar Heat Gain Coefficient ratings will be required in order to receive the ENERGY STAR for windows and sliding patio doors. To find out what these new ratings are, mouse over or click on your region to see the ENERGY STAR requirements for your region.
energy star climate zone map
NFRC certification
air leakage window criteria
Because Great Lakes Window has ENERGY STAR windows, the National Fenestration Rating Council (NFRC) labels are printed on all Great Lakes windows. energy star logo ecoSmart windows have been awarded ENERGY STAR Most Efficient for 2018. Be sure to consult your Great Lakes Window Dealer to make sure you are ordering the right energy-efficient glass package with your Great Lakes Windows. 2017 Energy Tax Credit Information   IREC logo
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T. Smith Siding & Windows is pleased to offer a number of patio doors and entry doors for Lexington Door Installation Services.

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We provide full service  Window Replacement Services and we have windows to fit every budget! If you want energy efficient, we’ve got it!

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The siding that you choose will make a big impact both functionally and aesthetically to your house.  Let us help you choose the type and color that will endure for years to come.

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Roof Replacement Services & ROOFING is definitely the one where “trying to do the job on the cheap” will come back to haunt you the most.

Doors, Siding, Roofing, Gutters and Windows; We’ll Be there.

Serving Central Kentucky


Products and Services


T. Smith Siding & Windows Inc.

100 Dewey Dr #A
Nicholasville, KY 40356
(859) 881-4466


Mon-Friday 9:00-4:00
Saturday by appt. only

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