Window & Doors Energy Efficiency
High quality, energy efficient windows and doors are a sound investment that will save you money over the long term, because they will last longer, perform better and reduce your heating and cooling costs.
Marlboro windows and doors meet the highest standards of energy efficiency and performance. All our products are manufactured according to Canadian Standards Association (CSA) requirements. We are also proud members of the:
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Canadian Window and Door Manufacturers Association | Ottawa Construction Association | ENERGY STAR® program | Insulating Glass Manufacturers Alliance | Canadian Standards Association |
Energy Efficiency Ratings
Marlboro's best-selling low-E argon vinyl windows are ENERGY STAR® approved. Most are approved for all Canadian climate zones, including the Yukon, Northwest Territories and Nunavut and all exceed ENERGY STAR® requirements for Canada's other three climate zones.
Zone* | Minimum rating for ENERGY STAR ® approval | Marlboro ratings for best-selling low-E argon vinyl windows | ||||||
Operating casement | Awning | Fixed casement | Single hung | Double hung | Single slider | Double slider | ||
A | 21 | 31 | 30 | 28 | 32 | 30 | 32 | 30 |
B | 25 | |||||||
C | 29 | |||||||
D | 34 |
* Zone A has the mildest average annual temperatures and Zone D has the coldest.
ENERGY STAR®-approvedwindows reduce energy costs, keep your home comfortable, reduce outside noise, and can also reduce condensation in cold weather. According to Natural Resources Canada, ENERGY STAR® qualified products will reduce your energy costs by up to 12 per cent.
Using energy efficient products also helps the environment. According to Natural Resources Canada, if you replaced all the original windows and doors in an average older home with ENERGY STAR® qualified products, your household energy consumption would drop by about 7 per cent, saving three quarters of a tonne of greenhouse gas (GHG) emissions annually. If you installed ENERGY STAR® qualified windows, doors and skylights in an average new home instead of conventional products, your energy consumption would drop by about 12 per cent.
Marlboro’s best-selling low-E argon vinyl windows also receive outstanding energy efficiency ratings in four key areas.
- Energy rating(ER) – With ratings as high as 38, our windows are up to 88 per cent more energy efficient than clear glass.
- R-value – With ratings as high as 3.45, our windows are up to 44 per cent more energy efficient than clear glass.
- Overall U-value – With ratings as low as 1.66, our windows are up to 50 per cent more energy efficient than clear glass.
- Solar heat gain coefficient(SHGC) – Our windows achieve ratings as low as 0.467.
Marlboro’s best-selling vinyl windows also exceed performance requirements for air tightness, water tightness, wind load resistance and forced entry resistance.
View the complete list of energy efficiency and performance ratings for our vinyl windows.
Need more info about your project ? Let us know. We can easily help you scope out and determine the best solutions for your home.
Energy Efficiency

Marlboro's low-E argon vinyl windows meet ENERGY STAR® requirements for all Canadian climate zones and achieve outstanding energy efficiency ratings. More info