Energy Efficient Windows

energy efficient windowsWindows. Look around, they are all over your home and office!  But are they energy efficient windows?

If you’ve ever broken a window it’s a unique experience, one that starts with exhilaration for destroying something with such a dramatic shattering results.  If you’ve ever had your window broken, there is no joy, just immediate concern about repair options.

Windows are typically the more energy inefficient part of our homes and relentlessly bleed heat and coolness and waste all that energy spent achieving your desired interior temperature.

Windows are the portal to your carbon footprint and with energy efficient windows you can enjoy a more sustainable lifestyle for years to come.  Another Green Blizzard addressed a related topic – Using Recylced Building Materials in Your Eco-Friendly House

There are lots of window options out there, everyone an improvement to what you currently have, if your windows are 10+ years or older.   Window manufacturers (suck Morley Glass in the UK or Anderson in the US)  and many others have made a major strides in with energy efficiency and energy efficient windows and replacements.  Its now more quickly cost justifiable as heating fuel prices continue to rise along with cooling costs.

If you were only going to do one thing to reduce your carbon footprint and how some money to invest your home – upgrade your primary windows and pull drapes across the other, unused windows.

One option is to install glazed windows, which will save you money on your heating and air conditioning.

Here’s an Energy Star Report and Map to help figure out your savings, and as you can see, replacing your old single-pane windows with Energy Star windows or energy efficient windows can save from $100 to over $400 a year depending where you live.  Energy Star estimates you will save 7-15%on your energy bills.

The blog House Logic from the National Association of Realtor has many helpful articles about evaluating energy efficient windows and  replacement options. You can see how buying all new windows and having them installed and sealed properly is a good idea just to save you money in the long run with the upfront investment, so consider replacing your windows regardless of whether a baseball or frisbee has broken one.

Want to know more about energy efficiency construction?  Check out this builder’s guide.   Or want some tips on saving energy around your house, check out this handy energy saving guide.

Looking into glazed windows is a great idea because you can buy custom windows for the climate zone you live in to maximize the winter heat/light and minimize the summer heat/light. Look for the National Fenestration Rating Council Sticker which will break down three important attributes of the windows:

Solar Heat Gain Coefficient – look for .6 or higher if you wish to maximize heat gain
VT – the higher this number is the more visible light will permeate your home
U Factor – look for under .35 to minimize heat loss for conduction – a key factor in assessing energy efficient windows.

The above recommendations are for areas in which you will want to take advantage of the sun for winter months. If you live in Florida, you will obviously want the opposite for solar heat gain coefficient as this will minimize the heat gain but still allow for lots of daylight to enter – you still want energy efficient windows. If you are installing a new window to light a room, you will want to cater it to the climate you live in, but make sure the VT is high to provide plenty of daylight and help you avoid turning on the lights. Here’s some recommendations if you live in a hot area and wish to cool your home, or minimize the sun’s impact upon it and thus reduce air conditioning costs:

U Factor – look for one under .4 as you still want to take advantage of the conduction
Solar Heat Gain Coefficient – look for one under .55 in order to lower cooling costs in your home.

Replacing old windows or even installing new lights or skylights help you conserve energy reduces your carbon footprint because it will reduce heating and air conditioning costs as well as decreasing the amount of electricity you use by making it unnecessary to use as much lighting during the daytime. In general, 5% of the room’s area needs an equivalent of glazed windows on the walls. So if you have an 200 square foot room, you would want to aim for 10 square feet of windows. You can reduce heating/air conditioning and electric bills by 1/3 or more with proper windows. This is quite a lot of money when you add it up for a year, and over 5 years you will see savings in the thousands of dollars.

You might also look into installing tubular lighting or skylights to help reduce the lighting costs of your home. Tubular lights are pricey, so they may not be economically feasible for everyone, but skylights are cheaper at around $500 and up which includes installation. What’s more, skylights are a new feature in architecture that has grown very popular for homes, so the investment will pay off when you are trying to sell your property. In general, if you install skylights, the price of your home will be higher so that the investment didn’t cost you anything in the end.

So next time that wild foul ball from the neighborhood baseball game or errant lacrosse ball comes crashing into your living room, consider the many alternatives for energy efficient windows because with a simple step you can save yourself money and help the environment.

Staff picks for other related energy efficient window articles are: Using Recycled Building Materials For An Eco-Friendly House, or Best Gifts For A Green Handyman.


About the author

John R. Garnet

John's work in the energy market fostered his interest in the environment. He recently completed his graduate work at George Mason University, But more interestingly, John has a passion for food and cooking and to provides some light-hearted tips to make people's lives greener while enjoy the good life with everyday practical tips from brewing tea, growing basil, or drinking raw milk.