Undertaking a historic building renovation? Building owners and developers applying for a Federal Rehabilitation Tax Credit – also known as the Historic Preservation Tax Credit – are urged to retrofit, rebuild and restore historic windows instead of replace them. They can use Indow inserts to make those original windows perform like high-performance double-panes.

Get a tax credit on windows by using window inserts during your historic building renovation.

Read more about The Secretary of the Interior’s Standards for the Treatment of Historic Properties.

Read more about the Historic Preservation Tax Credit.

indow window insert soundproof tax credit

How do Federal Historic Tax Credits Work?

Historic building renovations are appealing simply because they help retain materials and a direct tie to our history. But, our tax code provides another appealing reason: historic tax credits. These tax credits reward those who preserve rather than replace older buildings. If you want a full explanation go here: How do historic tax credits work.

For a tax credit on windows, either residential or commercial can apply, but you must file the paperwork associated with becoming a certified historic structure. Then you simply renovate the windows and install Indow window inserts to add energy efficiency and credit your windows.

indow window insert soundproof tax credit

Historic Preservation Through Window Inserts

Saving energy and adding energy efficiency doesn’t require replacing historic windows. A US Department of Energy study found Indow window inserts saved 20% in heating and cooling costs in a century-old Seattle home. In this way, window inserts help drafty single-pane windows perform like new double-panes.

Historic building renovations can also bring modern comforts like noise reduction. Older windows not only let in drafts, they let in noise since sound vibrations move anywhere air does. This can be a particular problem in historic commercial districts with pedestrian and vehicle traffic. Indow window inserts can reduce outside noise by up to 70%* without changing the appearance of the window.

Window Technology for Sustainable Buildings

It’s an important sustainability goal for many companies to increase the energy efficiency of their built environment while retaining as many existing materials as possible. Old-growth wood especially has significant amounts of embodied energy which Indow inserts allow to stay in place and out of landfill.

Historic building renovation helps residential property managers as well as commercial. Renters are attracted to the hustle and bustle of historic downtowns, but want peace and quiet inside. Apartment property owners can install Indow inserts to meet historic guidelines and keep tenants happy. They won’t be sad about the lower energy bills either.


*We want to ensure our inserts help solve your noise problem. Overall noise reduction depends on the amount of noise coming through your walls, ceilings, floors, doors, and existing windows. Noise reduction will be less when placed over double-pane windows. Read our full Noise Reduction Sheet to learn more.


Indow offers mullions for commercial and large residential projects. Mullions split the surface area of a window frame in two, making it possible to accommodate your largest underperforming windows with multiple Indow window inserts. Multiple panels in a single window frame joined by a mullion allows for a quicker, easier installation and allows you to access your windows by removing one of two smaller inserts.

Mullions come in a variety of colors to match your business’s window frames. We custom cut mullions to fit your window frames, and we can accommodate windows up to 8’ high or wide.


Indow Inserts are Perfect for Historic Building Renovation Because They are:

  • Safe for historic windows - no mounting hardware required.
  • Increase energy efficiency significantly.
  • Block up to 70% of outside noise.
  • Blend into the surrounding frame & aren’t visible from the outside.
  • Provides superior comfort.

Indow is a recognized leader in energy efficiency, sound, and comfort in the built environment. We offer courses for AIA accreditation providing attendees with 1 LU/HSW credit. Join those from backgrounds in adaptive reuse, multifamily, historic buildings on the national register, and more. See the AIA presentation schedule and sign up!

indow window insert soundproof tax credit
indow window insert soundproof tax credit

Indow is committed to historic preservation and increasing energy efficiency in older homes. Our inserts are powerful tools for those involved in historic property management. We have a pilot program to test our window inserts in one room of your property. To see if they’re available for your historic space, enter your zip code in the form below.

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