If It Can Be Restored Then We Shall Restore It

Whether we are draught proofing, installing slim double glazing, or both. We make sure that your windows are fully functional and structurally sound so that they will last a lifetime.

Period Window Restoration

Windows That Last

Original seasoned timber is in our opinion worth conserving at all costs. Often hundreds of years old, the wood is not only of a very high quality but has also moved and aged with the fabric of the building to become part of your properties original charm and heritage. It has stood the test of time.

We take great pride in the quality of the restoration work that we do and know from experience that there is only one way of doing things and that is the right way. No short 

Why Restore?

The main problem that we come across is water damage and rot, which when found has usually damaged the sill and bottom rail of the lower sash causing structural and functional problems with the window. If correctly restored and painted regularly your windows should last a lifetime.

Only in extreme cases is a window beyond repair. Should this be the case, we offer an extensive range of replacement bespoke joinery.

Keep reading to learn more about our sash window restoration process…

Rotten Timber Repairs

“We remove all rotten timber and repair any damaged wood with a unique epoxy resin. We scarf in new timber repairs if required.”

Sash Window Restoration Preparation

“The internal and external faces of the sashes are stripped of any loose, built up flaky paint and then sanded ready for primer. Conservation joints are glued, screwed and sanded.”

Box Preparation

“When restoring your sash windows, the boxes (frames) are stripped of any loose, built up flaky paint and repaired where necessary. We scrape and sand the boxes, leaving a sound base for us to apply a primer to.”

Cill Replacement

“Old rotten sills are removed and replaced with bespoke hardwood cills in keeping with the originals.”


“All bare timber surfaces are primed white ready for decoration when restoring sash windows.” (We can discuss your final decoration requirements separately)

Tell us about your plans. We’d love to hear from you.

Happy customers

Client testimonials

Natasha, Maida Vale


"I used Envirosash to make 6 new sashes as well as an entirely new sash window. The windows are of the highest quality, beautifully made and draught-proofed. They keep the flat much warmer and we've already noticed how much quieter it is. Alex was competitive on price even taking into account the quality materials that he uses. I wouldn't hestitate to recommend Envirosash on the basis of their craftsmanship, reliability and general ease with which they performed the job."

Mervyn, Crouch End


"Alex was a pleasure to deal with and the job was done on time and as expected. His workforce did a high quality job and were always polite, helpful and attentive. They also made sure to clean up at the end of each day. We had most of the windows in the house replaced and it has made a real difference. Happy to recommend."

Sarah, Gravesend


"Had some replacement slim double glazed sashes fitted recently. Good craftsmanship and thorough job. Cleaned up every evening. Good to have a quote from someone who actually understands the work to be done, rather than from someone who is just a salesman. Would definitely recommend."

The Timber Window Specialist