Sash windows specialists

Get a quote

Our sash window specialists preserve traditional box sash windows and other styles, such as casement windows, french doors, bay and Bi-Folding doors. 

  • 8 Years Paintwork Guarantee
  • 20 Years on Repaired Parts
  • 15 Vacuum glass
  • Google Rating

Chameleon Sash Windows Specialist provides wooden windows restoration services in East Anglia and South East. We restore traditional sash windows and work with private and commercial clients on all period properties.

Our team specialize in restoring and double-glazing all styles of original sash windows, french doors and casement windows in Grade 2 listed buildings or buildings in conversation areas. We provide a cost-effective alternative to complete sash window replacement, ensuring energy efficiency and preserving the historic appearance.

Our sash windows specialist services

Our comprehensive range of services is committed to preserving traditional sash windows while improving their energy efficiency to compete with modern A-rated windows.


Wooden window frame refurbishment

Learn more

Our window specialists are experienced in handling all types of timber frame issues. Over the past ten years, we have restored thousands of sash windows. We understand how to enhance the durability of restored frames, making them as long-lasting as those made with Accoya wood.


To achieve this, we have developed our unique timber laminating technique, which imparts exceptional durability to the original sash windows undergoing restoration.





Sash windows draught-proofing

Learn more

sash window specialists in draught-proofing



Sash window draught-proofing is a great option for Grade 2 listed buildings to remove rattling and draught. It does not require planning permission. We usually do window draught-proofing with timber frame repairs or double glazing retrofit.

Our team instals new staff and parting beads with draught-proofing seals and adds weather seals to the meeting rail. We can also draught-proof casement windows and french doors. 


Repairs and functional restoration

Learn more
  • Unblock stuck sashes

    Unblock stuck sashes

  • Repair broken cords

    Repair broken cords

  • Rebalance weights

    Rebalance weights

  • Replace Pulley

    Replace Pulley

  • Install restrictors & stops

    Install restrictors & stops

From sash cords repair, glass pane replacement, and window sill replacement to unblocking painted shut sashes. We can restore the functionality of your sash and casement windows. 


All sash window repairs are included in our sash window refurbishment & draught-proofing price


Say goodbye to draughts, heat loss, and excessive external noise

Learn more
  • External noise pollution

    External noise pollution

  • Cold draught

    Cold draught

  • Condensation on windows

    Condensation on windows

  • Bulky secondary glazing

    Bulky secondary glazing

  • Heat-loss through windows

    Heat-loss through windows


Living in a period home with single-glazed windows, you’re well aware of the challenges during winter, as well as the effort and cost required to heat your home. Moreover, if you’re situated near busy roads, you know how easily sound penetrates your home through a single pane of glass. 


We have encountered numerous properties facing this issue and have successfully helped many homeowners achieve what once seemed impossible: installing double glazing with all its associated benefits while retaining the original timber frames.


All of this has become possible due to the innovative vacuum double glazing, which is only 7mm thick. Its slim design makes it an ideal fit for the narrow stiles and glazing bars of period sash windows. This new generation of glass delivers superior thermal performance and U-value compared to double Low-E and 34mm triple glazing.



We specialise in sash window double glazing retrofitting

Our team of sash window specialists can replace inefficient single-glazing in the original box sash window with heritage double-glazing. This will improve the energy efficiency of your traditional timber sash windows and reduce energy bills.  

The thermal photo below shows double-glazed sash windows by our team.

The ground floor window of the period property is single-glazed, while the window above it has been retrofitted with slim-profile double-glazing. You can clearly see the significant thermal difference between the two.

double glazing for sash windows thermal imaging

Traditional wooden sash windows can now be double-glazed, so you do not need a more expensive window replacement service. 

The new generation of double glazing (VIG – Vacuum insulated glass)

The innovative vacuum double glazing is eight times more efficient than single glazing and four times more efficient than secondary glazing. This advanced glass technology also boasts greater durability than standard double glazing insulated with inert gases like Krypton and Argon.

U-value of different glazing solutions 

The U-value measures heat loss; it tells you how energy-efficient glazing is. The lower the U-value, the better thermal insulation glazing has.

  • Single glazing: 5.2 W/m²K
  • Regular double glazing (is not suitable for retrofitting): 1.2 – 1.9 W/m²K
  • Secondary glazing: 2.7 W/m²K
  • Triple glazing: 0.8 W/m²K
  • Our vacuum heritage double glazing: 0.7 W/m²K

We don’t sell replacements and promote draught-proofing as a miracle solution

Unlike other sash window companies, our primary focus is window refurbishment and retrofitting; we don’t sell new windows or double-glazed sash inserts. Our expert team is dedicated to the concept of repair rather than replacement.

We also don’t promote draught-proofing as a miracle solution for all energy efficiency issues, as some companies do.

Our approach is direct and honest; we will only recommend a service that effectively addresses your problem. The staff members who attend our quote meetings are genuine window experts, not salespeople.


For your peace of mind, our services come with guarantees from our company and manufacturers of products we use, such as vacuum double glazing, timber, and seals.

We offer an eight-year paintwork guarantee and 20 years on repaired timber window parts. The vacuum double glazing we use has 15 years manufacturer warranty covering failed double-glazed units. 

What Customers Say

We pride ourselves on delivering a high-quality job that our customers will be delighted with. Don’t just take our word for it, have a look at what our clients and customers have said about our services.

Really pleased with our windows! Prompt and helpful communication, extremely hard working team and a great looking (and hopefully better functioning) end result. Thank you!

Vanessa Nash

Alex and the team have restored our 20 year old sash windows so they look brand new. The team worked non-stop to complete it and made sure everything was to an excellent standard. Thank you.


We’re very happy with the work we recently had completed on the windows. It was also done in great time, with the guys coming nearly every day, including weekends – absolute grafters. Thank you, our windows look great!

Sarah Mayne

We had an excellent experience with Chameleon Decorators. The work was completed on time and to a very high standard throughout, all at a fair price. Would have no hesitation in providing a recommendation. Please note that the team work on the exterior only so you will need to factor in an internal job also!

Oliver Taylor


Very pleased with the results, very professional service. Would recommend.

Stephen Mcmullen

Excellent communication, service and professionalism. We spoke with Chameleon to restore some rotting wood french doors and wooden windows, as well as redecorate. We’d use them again without hesitation and would thoroughly recommend them.

Jamie Newman

Alex and his team are superb. We have used them before, and always been impressed – as we were this time – by their work ethic, their expertise and knowledge, the quality of their work, and their efficiency. I recommend them very highly indeed.

Emma Goddard


Our completed projects

    Windows refurbishment in Care home – Old Vicarage Care Home, St Neots

    Windows refurbishment in Care home – Old Vicarage Care Home, St Neots

    Sash windows restoration in Suffolk

    Sash windows restoration in Suffolk

    Sash windows restoration in Cambridge

    Sash windows restoration in Cambridge

    Sash Window Refurbishment in Hertfordshire

    Sash Window Refurbishment in Hertfordshire

    Retrofitting original sash windows with double glazing in Suffolk

    Retrofitting original sash windows with double glazing in Suffolk

    Double glazing retrofitting in Wing

    Double glazing retrofitting in Wing

Contact us for a free quote

If you are looking for reliable and professional sash windows specialists with executive customer service in your area, look no further than Chameleon Windows! Contact our friendly team today, and we will be happy to restore your windows.