Windows are a major source of energy leakage.  Nationally windows cause 34% of overall energy use in commercial buildings and 30% in residential buildings.

Windows have a fraction of the R value of the wall next to it.  One pane of glass is approximately 0.91 R value. Two panes with a 1/2" air space is approximately 2.04 R value (0.49 U value).   The walls by comparison next to the windows are required by code in our area to be R19 or better.  

These conductive losses are only part of the problem.  The seals around windows break down or were never good to start with.  Windows on the lower levels of the building are in a low pressure zone and allow cold air to infiltrate.  Windows on the higher level areas are in a high pressure zone allowing warm air to escape.

Window replacements are very expensive and it is hard to justify the economics with the energy savings new windows provide.  Window retrofits on the other hand make tremendous sense.  Window retrofits cost a fraction of the price of replacement windows and retrofits  can be used on many of the windows in Minnesota improving them to levels that exceeds ENERGY STAR standards.

Our window retrofits are custom made by the Green Home Doctors and use clear sheets that fit over your existing windows.  They snap into place and effectively blocks out air leakage around the framing of the window and adds considerable R value to the window.

Imagine touching the window of an airplane flying at 38,000 feet.  The air outside is -40 F degrees, yet the window inside is relatively warm.  This is because instead of using glass on the planes window, these are made of acrylic and has an R value that is over 5 times that of glass.

Noise from highways and the city can be effectively reduced by using our window retrofits.  We can also use UV filtering plexiglass to protect your homes interior. In some special scenarios we can provide opaque plexiglass for privacy concerns or us plexiglass that  reflects sun light to help keep your home cooler in the summer.


Our Services


We provide free energy assessments.  As State of Minnesota certified energy auditors we have the tools and resources  to provide valued insight and perspectives.


Considerable detail goes into sealing the building envelope. We adhere to 'best practices' and this work is done prior to insulating.


We specialize in cellulose and closed cell foam as we have found these to be superior insulation materials. We often avoid fiberglass . Ask us why.


We provide a way to greatly improve the efficiency of your existing windows, but at a fraction of the cost of replacements.


Get in touch

Green Home Doctors
4737 County Road 101, #163
Minnetonka, MN 55345
P: (612) 216-1640

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