Hey Guys,

Im looking at buying energy efficient windows for my home. I hear they can considerably reduce heating loss in winter while keeping the place cool in Summer. Does anyone know rounghly how much they cost and are they worth the investment?

Looking here - https://priceexperts.co.uk/window-prices/energy-efficient/ - there’s a rough estimate. Does anyone have any experience cost versus benefit?


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  • The calculation involves heat loss across the window. Calculate the difference based on the u-value of each window type. Calculation is also climate specific. Then translate that BTU difference into dollars based on fuel type used and cost per unit of that fuel type. (Or, easier, run it through modeling software)
    • Thermal resistance is largely determined by the nature of the insulating material, its thickness and Its percentage in the surface area of the envelope.   Therefore, you are going to lose a relatively high amount of thermal energy over a relatively small surface area.  Secondly, insulated glass is relatively fragile and will not tolerate stresses of any kind, and explains why even the best windows seldom have more than a twenty-year warranty.  Triple pane glass invites the same failure rate at a much higher replacement cost.  The window industry is struggling to reach the R-4 initiative, which is still a relatively poor insulating value.  Oddly enough, you can obtain the same or better performance (because of the increased airspace) by adding a storm window to a primary window, as well as possibly an interior storm.  The simpler a system becomes, the better it will perform over time.

      • And storm windows are now available as an "Energy Star" product - a very worthy option for the home owner that desperately needs to improve their window situation and have a limited budget. Installation is much less complicated too.

  • I know windows have a long payback period as compared to other improvements such as insulation, air sealing, duct replacement etc. What I'd like to know is once the decision is made to upgrade windows is it worth paying more for say the more premium, triple pane windows with the higher R-value framing, etc. Once the decision has been made (probably at least somewhat on price) to upgrade is there an ROI on spending more than say a basic double-pane window you'd get at Home Depot vs a more expensive, premium one? Does anyone know?

  • As others have said - replacement windows are helpful for comfort but don't expect them to payback in energy savings alone.

  • Good windows matter, particularly in super cold climates, if you're floor plan has you sedentary near a window. 

    It's a mean radiant thang....

    Energy payback, 1000 years. Comfort payback, priceless.

  • To really know how much you are going to save it is important to know the current condition of the windows you have.  It will be much more worth your investment to hire a window replacement company, if your windows are more than 10 years old, have some defects and you notice things drastic temperature fluctuations in certain rooms.  Our window replacement company in Denver prides itself in being energy professionals FIRST and if you can find a company that will give you genuine advice and numbers, you should be in good hands.

    Here is a good guide on different energy efficient window styles, that should further your research: https://replacementwindowscolorado.com/energy-efficient-windows/sty...

    The Best Windows in Denver in Every Style Imaginable
    Compare styles of the best windows in Denver. 60+ years of combined experience, certified contractors, & warranties! FREE quote (720) 730-6606
  • There is more to windows than just their individual performance- they are usually the least efficient part of the building envelope.  That means that in cold temperatures- they are the surface for condensation of moisture- and if that's not controlled- mold and rot.  Replacing windows and controlling condensation are items that need to be considered together, as even with good interior air circulation the differential R value will still lead to condensation. 


  • There are so many factors to consider when replacing windows. For example, if you block the heat gain from the winter sun, it will increase your heat load. But if the home has deciduous shade or awnings that will block the summer sun, then you could use a lower SHGC and retain the winter heat gain. Not all windows in the home need to have the same SHGC. Leaky, drafty windows need to be replaced, but you need to understand the SHGC and the U Value.

    • So many replies - obviously this is a hot topic :)

      I agree that unless the existing windows are single pane, changing windows for the sake of energy savings is not cost effective.

      I haven't read all the posts but I didn't see anyone mentioning low-e storm windows. The cost of the product would be much less and the cost of installation would also be much easier and much less expensive so they are considered cost effective here in the northwest. Last I heard, some of these are at the precipice of achieving the Energy Star designation.

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