At Sash Window Experts, we recognise that double-glazed windows are now an essential feature of the modern home, with many proven benefits over single-glazed period windows.

We work with the latest advances in technology in the double-glazing industry to provide beautiful double-glazed sash windows in hard or soft wood, that have the following advantages.

Benefits of Double-Glazed Period Windows

Greater Energy Efficiency

Recent figures have shown that somewhere in the region of 50-70% of heat in the home is lost through having single-glazed windows. Installing double-glazed windows achieves better thermal performance by trapping a layer of air between two glass panels. It is one of the most efficient ways to improve the energy efficiency of your home.

Lower Energy Costs

Changing your windows from single-glazed to double-glazed sash windows will help you keep more of the heat in your home. This means you can keep the central heating thermostat turned down in order to reach the same internal temperature, saving on energy consumption and utility bills.

Better Sound Insulation

Changing your windows from single-glazed to double-glazed sash windows will help you keep more of the heat in your home. This means you can keep the central heating thermostat turned down in order to reach the same internal temperature, saving on energy consumption and utility bills.

More Home Security

Double glazing is also an effective method to provide a greater level of home security, and the peace of mind that comes from knowing your family is safe at all times. Particularly on the ground floor, modern construction methods and double-glazed window panes will make it much harder for any intruder to gain access.

Easier Maintenance

Timber-framed, double-glazed sash windows have a timeless appeal that perfectly complements older properties and listed buildings. Routine cleaning with warm soapy water is all it takes to preserve your windows. Carry out periodic checks for moisture ingress, and wear and tear and apply a fresh coat of paint where necessary.

Can You Retrofit Double Glazing Sash Windows?

Installing double glazed sash windows to replace original single glazing may not always be possible without planning permission, for instance in period properties in Conservation Areas or listed buildings. One way to get around this is to leave the original windows in situ and retrofit double glazing into to the existing sash windows.

Retrofitting double glazing to timber windows is done by removing the existing single panes and replacing them with new slim-line low-profile heritage double glazing. These can be retrofitted into narrow rebates of original timber sash windows. Heritage double glazing uses slimline, low-profile double glazing units with exceptional thermal insulation that will improve their energy efficiency to match the performance of a modern A-rated window.

This alternative type of double glazing installation ensures that important original architectural characteristics of historic properties are preserved while providing the convenience of energy efficiency.

Double Glazing For Sash Windows

Sash Window Experts have more than 30 years of experience in restoring period windows. We can offer beautiful double-glazed hard or soft wood sashes that incorporate warm edge technology that is normally used in modern sealed units while retaining all the essential period features including the original moulding design and horn detail.

All our work is carried out in our joinery workshop, using skilled and experienced craftsmen that share a passion for heritage architecture. Our team will:

  • Supply and fit a pair of new double-glazed sashes into your original box frame
  • Reinstate double-glazed sashes into the original box frame where they’ve been previously replaced with modern aluminium or UPVC versions
  • Fit a full replacement box frame and double-glazed sash windows with traditional pulleys and weights, where these were completely removed

For details about double glazing for sash windows, or any of our other sash window repair and restoration services, please call the Sash Window Experts office on 01403 602701 or fill in the form on our Contact Page to send your enquiry or arrange for a free quotation.

Arrange a No Obligation Survey With Mark

Hi, I’m Mark, owner of Sash Window Experts. I’d love to talk to you about restoring period windows. Please fill out the form or call me on 01403 602701 to arrange your FREE no obligation window survey and to discuss your requirements.

What Our Customers Say

Helen Thomas
If I could clone you for all the other work we need to do over the next few years, I would! Thank you Mark for having such a good team in place. And huge thank you to Gary, Alex, John and Glen for taking such care of our windows and giving them what they needed after years (decades?) of neglect. Your attention to detail and 'doing it right' was very much appreciated, and your ability to solve problems was awesome. Helen & Tim, Godalming
Roxana Avanu
Amazing service from start to finish, no issues and no drama. The name Sash Window Experts is well chosen. Mark and his team - Gary and John were extremely helpful and professional and the end product - new sash sound proof double glaze windows upstairs and the kitchen triple sash window restored was top quality. I am very grateful to Sash Window Experts.
Amy Clarke
Cannot fault Mark and his team. We replaced the original sashes to our 1890's home with new like-for-like hardwood double glazed sash windows, and apart from being warmer, quieter, cleaner and altogether much smarter, you really wouldn't tell the difference - an amazing feat! They are absolutely beautiful windows, so well crafted and fitted, and the restoration of rot on the original box is imperceptible. Gary was friendly, clean, professional, and safe throughout the fitting, and very thoughtful in causing minimal disruption to the home. Absolutely thrilled with everything from the service to the price to the final finish. Delighted with them. Would recommend in a heartbeat.
Alison Fordham
We were nervous about getting our Victorian French windows restored and had received a ridiculously high quote. Sash Window Experts came in at a good price, gave a timeframe that worked with our schedule and did a great job. All as promised. The fitter, Gary, put the doors back in with great care and took time made sure they worked smoothly and also discussed any queries with us. Definitely made the job value for money. Very happy customers! We are looking forward to beign able to open our doors again and enjoy the garden. Thank you Mark and Co!
Peter Jones
Our house is Edwardian and has the original sash windows from 1906. I really want to make sure that any double glazed windows did not look out of place - so the woodwork, including the side bars etc should still be very thin to match the originals. I was fearing ending up with fat wooden bars but Mark took me to see a previous customer and I was happy to see the woodwork there and it put my mind at rest. We went for the thin Krypton windows. Now the windows are in they look very good and match very well. To be fair to everybody, we will not know until the winter how well they remedy our warmth and condensation issues in the house but are confident we made the right choice. Other suppliers would not do separate window panes and instead would only do a large window with a false wooden strip down the middle to make them look like two. We did not want that. The carpenters, Steve and Gary turned up on time (early actually) and got on with the job very efficiently and left no mess behind. I am very happy with the company and the windows.
Natasha Birley
Mark and his team are amazing. They restored our sash windows and doors. Mark is really knowledgeable and passionate and explained the process to me so I knew exactly what they would be doing. Once the work commenced I was amazed by how well they draft proofed the windows. They took so much care and the guys were polite, tidy, timely and a joy to have around. I would absolutely recommend the team to anyone thinking of restoring their windows, they look AMAZING!
Rachael Smith
Absolutely outstanding quality, value for money and service from Rob. This is the second time Rob has done work for us and we can highly recommend him. The sash windows are like new! Thanks Rob 😀
Jon Reed
Used these guys to do a total refurbishment on the windows of my 1870s Victorian Villa style house. Incredibly happy with the work and the guys doing it are just superb. On time to the minute every day, clearly take pride in the work they do and super friendly. Would not hesitate to use again!
Geoff Parsons
Excellent service from Mark. The windows installed last week. Look elegant and noise reduced considerably.
S Attewell
Very pleased, very sound work done, very professional and friendly team. Highly recommended!!