Replacing sash windows – what you need to consider

Thinking of replacing your sash windows? It’s not as complicated as you may have thought, but there are a few things that you need to consider and keep in mind as you decide what to replace them with. To help, we have compiled a list of what those are and why they are important.

Should I replace?

Sash windows are typical of Georgian, Victorian, and Edwardian architecture, although they are widely used across modern designs as well. Original sash windows are made of timber although there are a number of uPVC options currently on the market. There will come a time when the timber frames of your original sash windows will start to show significant wear and tear. It may still be feasible to repair them and it is recommended that you do wherever possible in order to retain the character and look of your home. If you do opt for repair this will involve removing any rotten timber, draught-proofing, re-balancing the sashes, and servicing the pulleys to keep you windows going for a good few more years.

When you definitely need to replace your sash windows

If the damage is beyond repair then it’s time to replace them. A few things to keep in mind as you decide what the next steps are:

  1. Conservation areas. If you live in a conservation area the chances are that there will be some restrictions on what you can do when you replace your sash windows. This is so that the character of the area is retained. For example, it may not be possible to replace timber frames with uPVC ones, or that the replacement must be a like-for-like design. Check with your local authority’s planning team for advice if you are unsure.
  2. Planning permission. If your home is listed or in a conservation area you may need to apply for planning permission before making any changes to your home. There are a number of factors that may determine this so it is best to seek advice early – check the Government Planning Portal for details on what may be required. Again, this is done to preserve the character of a building and the local area.
  3. Choosing between timber and uPVC. While there are some excellent uPVC options on the market, there are pros and cons to both types of material. While timber will last longer it requires more maintenance than uPVC which in turn will require less maintenance but will have to be replaced in whole when the time comes – unlike timber. While uPVC offers greater security and energy efficiency, this can also be achieved by opting for a secondary glazing option if you choose to stay with timber frames.

 While there is plenty to think about when you are considering whether or not to replace your sash windows, rest assured that it is not as complicated as you may initially think. With more and more designs on the market, as well as bespoke solutions, it is possible to replace you sash windows with something that is similar to what you have so that you do not lose the character of your home – from the inside as well as the outside.

If you are thinking of replacing your sash windows and would like some advice and to talk through the options, Wandsworth Sash Windows is here to help. Give us a call on 02079247303 and one of our team will be happy to assist.

Contact the Wandsworth Sash Windows team

Talk to us – we can help with your bespoke window, door and joinery requirements. Call 02079247303 or email