My windows have had it. Timber sash vs uPVC?

Discussion in 'Other Trades Talk' started by Zidecke, May 9, 2024.


What do with these windows?

Poll closed Yesterday at 3:05 PM.
  1. Refurb

  2. Replace it all (and surrounding) with TIMBER SASH

    0 vote(s)
  3. Replace it all (and surrounding) with uPVC

    0 vote(s)
  1. Zidecke

    Zidecke Member


    Do you think the attached windows are refurbish(able)? If so, does that mean keeping the existing (single-glazes) panes and refurbing the box and wood? Any idea how much this might set us back?

    If not refubish(able), I will look to replace with either a double-glazed timber sash or uPVC.

    If opting for uPVC, I heard a rumour that there are some uncanny imitation-wood options out there (and some with sash too, if I remember correctly).

    What does the forum think?

    Attached Files:

  2. Mark DM

    Mark DM Screwfix Select

    What's the external condition like. Post more pictures for a better assessment. Internally doesn't look too bad
  3. Astramax

    Astramax Super Member

    Are you located in a conservation area?
  4. rogerk110

    rogerk110 Member

    I've just been through the same decision process as you're going through. It's for my son's house in London, and I know he won't repaint wooden windows every 5 years like you're supposed to, so we opted for Timberlook windows. His house is in a conservation area, so he needed something that wasn't going to get him in trouble with the council, so these seemed to be the best option.
    They are now in and look really good and work extremely well.
    FWIW, I have just been through the extremely tedious experience of repainting all my wooden windows in my own home, and would love never to have to repeat it. Hours and hours up a ladder was not fun!
    Zidecke likes this.
  5. Mr Rusty

    Mr Rusty Screwfix Select

    IMHO a house that has sash windows should keep sash windows, which gives you several choices:-

    1) Have the sliding sash rebuilt single glazed as original and have the box (parting and staff beads) fitted with draft proofing.
    2) Same, but have the sliding parts modified to take a DGU and increase the weights by adding lead - (there should be enough space in the original box to add enough lead on top of the existing iron weight, if not convert to all lead)
    3) Have new timber sash windows made up, preferably in Accoya which should last for ever and often will have a 10-12 year paint guarantee - very expensive
    4) As @rogerk110 use a uPVC window - some look pretty good. However, if it is in a conservation area or even worse, listed, then it is worth checking what is acceptable.
    Zidecke likes this.
  6. Zidecke

    Zidecke Member

    Thanks for the replies so far!

    As requested, here are some photos from the outside.

    Regarding these options from @Mr Rusty , is anyone able to ascribe estimate ranges to these 3 options?

    Thanks in advance,


    PS. I'm sooo happy that we've received 4 votes for refurbishing and none of a complete re-fit. I assume it will save £££s.

    Attached Files:

    Last edited: May 14, 2024
  7. Cris 11

    Cris 11 Active Member

    Plastic every time for me if allowed, double or triple glazed just a wipe over occasionally they don't swell and get stuck better insulated and less noise.

    I cant actually think of a good reason for using wooden windows and doors over upvc.

    Not sure they even work out cheaper mine have been in 20 years and still look like new.

    If they were wood I would have had to pay someone to paint them 4 or 5 times over the last 20 years.
    BuildingMad and koolpc like this.
  8. BuildingMad

    BuildingMad Screwfix Select

  9. Mr Rusty

    Mr Rusty Screwfix Select

    For my own house, I made my own sash windows in Accoya to match the original timber windows - there is something about timber that uPVC just doesn't quite replicate. However, the windows in @BuildingMad 's link above to me look very smart, and seem really good value; I would be very tempted to replace using these IF, and it is a huge "if", you can get someone to measure very accurately to minimise the amount of plastic frame showing, (if they measure just in to the visible rebate for the narrow sides of the bay, there will be a lot of plastic showing and much reduced glass) and is able to make up the space where the original boxes are, and deal with all the detailed redecoration required.

    Box sashes are a relatively simple construction, and well within the capability of a joiner. The photo's of the OP's property to me seem to show that the boxes are in reasonable condition and could be refurbed using new parting and staff beads - eliminating the need to destroy the internal decoration, possibly coving etc. Making new sliding parts is a joinery job. It is possible to design a new profile section to slide in the original slots in the stiles, but be a bit thicker to accommodate a DGU - these can also be designed for dry glazing and internally beaded. If this is the chosen route, you need someone knowledgeable about sash windows - typically the single glazing may well be 3mm. a DGU will most likely be 2 x 4mm - you will need to add 3-6kg of lead either side to balance, so the box needs to be big enough to take the extra weights.

    Lots of options. - If there is a bigger refurb going on anyway internally, then replacing with uPVC has a lot of benefits. However, don't underestimate the amount of disruption and making good taking out the complete box frames will entail internally. With box sashes most of the frame and box is hidden behind the facing in an internal rebate and will be covered with various timbers and constructions internally, whereas modern windows are usually fitted inside a flush rebate with the whole of the frame visible externally. As ever, the devil is in the detail, not just the cost of the base window. Ideally the new frame wants to be hidden behind the stonework as much as possible, minimising the amount of visible plastic and replicating the original appearance, but that may well mean stripping out to take accurate measurements - the width of the frames may be governed by the internal angle (unlikely because uPVC frames are much slimmer than the original boxes) - but they can't be closer together than with the frames touching on the internal corners, so new frames need some very accurate measuring for the best traditional appearance. The original box rebates may/will need making up to support the new frames. It'll take someone to take good measurements and make accurate drawings of what is already there, and then use the manufacturers CAD frame drawings superimposed to work out how the bay is going to be converted. If someone just turns up with a tape measure, and spends 10 minutes measuring up ready for fabrication, run away!

    Worst case, someone rips out the old, bricks up the rebates flush, makes up new frames to fit flush in the visible opening, and just foams them in with some cover strips internally - it'll look like a dogs dinner!

    Full timber replacement will require deep pockets (because it isn't worth putting in cheap timber) and probably is only an option even to consider if a conservation area or listing prohibits PVC.
    Zidecke likes this.
  10. Zidecke

    Zidecke Member

    Thanks @Mr Rusty - I've got a local "sash repairer" coming to provide a quote in the next couple of days and your pointers will prove invaluable.
    I will report back ASAP!

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