Average Labour Cost/Price to Replace/Refurbish Sash Windows

To clarify the following prices it is recommended that you read the article in the INFORMATION box below the PRICES…

(These prices are based on a tradesman’s rate of £150.00 per day and a labourer if required at £100.00 per day. This includes the cost of buying and collecting any materials, dumping any waste if necessary and any incidental materials they will need. The minimum price will usually be for a half day)

How Much Does It Cost To Refurbish Sash Windows?

sash windows

Job 1
To do the work outlined in our article below to one 5’ x 3’6” ground floor Victorian sliding sash window will take 1 man 5 days plus about £110 in materials

Price: £860.00

You can more or less say it will be the same for every window, some will be a bit smaller of course but the labour is the same and maybe he will want
scaffolding to reach the first floor.

Just possibly, this is why people get new double glazed ones made, with 10 year guarantees.

Job 2
all the casements fixed and opening, out of a 1930’s semi, which has a full bay at the front (about 24 of them). Remove all the glass, remove all the catches, burn off all the paint, enlarge the rebates, fit double glazing, re hang them all, fit new trendy catches.

This took
me (never mind some fictitious Charlie), an actual builder, about 5 hours per casement in labour and about £60 in materials.

Price: £3690.00

Then every one of them needed painting including all the frames, which I still had to prepare. They looked OK, when they were finished but the whole exercise didn’t cost any less than new double glazing and everything needed painting again in 4 years or so!

Job 3
To replace a 5' x 3'6" sash window with a NEW softwood sash window (making good plasterwork)

Price: £1100.00

For your must-see guide to Tradesmen's Rates please click on the map…


A Price Guide and Information Sheet on Refurbishing Sash Windows

Some windows are just too splendid to rip out and replace with modern double glazing, even if its wooden framed double glazing. I’m talking old ones of course, Georgian or large Victorian ones or possibly even a curved bay window with metal “Crittal” windows fitted.

No matter what the reason, don’t expect to get away with a vastly reduced bill as a result of not having to buy new ones. Refurbishing existing windows is very labour intensive and the builder’s brand new van needs paying for.

If the windows are Victorian or older, you will run into glazing problems. Glass comes in different thicknesses and very often, Victorian ones are
glazed with 2mm thick panes. It’s illegal to refit with 2mm glass today as it’s just a bit too dangerous for us soft millennium folk. Obviously the Victorians didn’t mind if young Ebenezer lost the odd thumb now and again playing with his new fangled rubber ball in the front room but we will spend far more time looking for someone to sue, than we do bandaging up young Ollie’s dripping digits.

The reason why the glass will need refitting is because it is very likely to break during the process. Each casement (that’s the moving bit with the glass in) will have to come out and be stripped of all it’s paint. There are three ways to remove paint. Scrape it off (the best edge to use is a piece of glass), dissolve it with a preparatory acid (“Nitromors” is one brand but there are others), or burn it off. The first two are very slow and will cost an absolute fortune, burning off by someone who knows what he’s doing is nice and quick.

If the window is being left unpainted and let’s face it, they do look good unpainted, provided they are waxed, he will have to know what he’s doing, or there will be an awful lot of burn marks to sand away.

Burning will crack the glass, which will then need replacing. The minimum allowable thickness is 3mm today (other than in a greenhouse I believe). This is ok, you won’t notice the difference but if the windows are sliding sashes the balance will be affected. Sliding sash windows don’t stay at the point where you leave them by magic, they have lead weights hidden in the frames at the other end of the sash cord. These move up and down and always counterbalance the sash because as near as dammit they are the same weight as the sash. If you fit 3mm (heavier) glass this balance is affected.

However this can be countered by adding additional small weights to the existing ones until it all comes right again!

There is another problem, some windows are fitted quite low to the floor. If these were to be fitted today and any glass in them were to be 800mm (31.5”) or less from the floor then that glass would have to be safety glass. This means either fitting much thicker panes (possibly 6mm or ¼” thick) or having the 3mm glass “tempered” at extra cost. If you replace the glass then the new stuff will have to comply with
today’s regulations. You don’t however have to fit double glazing if you are just replacing the glass. You do if it’s the whole window though. (Unless it’s a listed building).

Don’t attempt to fit double glazing into existing Victorian sliding sash windows. We’re talking two panes of glass each 50% thicker than the original. You will never be able to counterbalance them, there won’t be enough space inside the frames to fit the heavier counterweights.

You can fit double glazed panels in “normal” wooden casements though. Normal casements are the ones which are hinged at the sides and just open outwards with a little “stay” at the bottom to stop the wind annihilating them. These will have to have their glazing rebates enlarged with a machine called a router. It can all be done on site but the shavings will go everywhere.

Double glazing becomes more
energy efficient as the gap between the two panes of glass increases (up to a point). As your old wooden casements are quite thin relevant to modern ones, they will only be able to accommodate double glazing with a minimum air gap between the panes, so the energy saving will be less. However the sound deadening ability will not diminish as it’s solid things which stop sound and there will still be two panes of glass.

Before the double glazing is fitted, the rebates will need to be primed. When this is dry the units can be fitted and puttied in with the correct stuff. If ordinary putty is used, the linseed oil in it will leach between the panes of glass in the double glazed unit and this will become very unsightly over time.

If you are considering refurbishing metal “Crittal” windows, which are either rusting or warped, then it is vital to remove all the paint by burning off. This will crack the glass so if you have those curved panes in the
bay window, make sure you can get replacements before you start! Make sure the builder gets right back to the galvanised steel then applies rust inhibitor to the rusty bits before repainting. I suggest they use smooth “Hammerite” paint, it’s designed for metal and comes in quite a lot of colours nowadays.

If the casements are warped and need quite a pull to close them, the process of removing the ten coats of paint that they have on them at the moment, will probably sort the problem out.

Refurbishing Victorian sliding sash windows is horrendously time consuming. The whole thing has to be taken apart leaving only the frame in position. There will be rotten wood at the bottom and the external bit of the cill may need to be completely replaced. All rotten wood has to be cut away. ……….
There is always far more rot than you think and sometimes the hole can be terrifying. However there are brilliant 2 part fillers on the market and with a bit of TLC the window can be returned to its original condition. It takes time though. First the newly exposed good wood needs to be primed, then if the hole is large, lots of anodised screws (they won’t rust) fixed into place to form a key. The 2 part filler comes next, it will set like steel in ten minutes. It may take 5 applications but with care, a sharp chisel and lots of sandpaper, it’s possible to return the area to
exactly its original contour. You have to paint it though!

Besides the wooden bits, there are the pulleys which need to be considered. These are cast iron so soak them in acid and then leave them showing. Have the four sash cords replaced and put some form of security feature in the downstairs windows. One type is set into the frame and allows the sash to be opened about 100mm (4”) so air can get in but not the bad lads.

If you want to go daft, have a
proper brass central opener fitted and even bottom sash “puller uppers”, though with all this work, everything should slip up and down like a dream.

Two types of wooden beads will have to be removed during the process. The “staff” beads are the first to come off. Make sure he takes his time with these and doesn’t snap them. Similarly when he removes the “parting” bead he must use the same care. If you are intending to leave them unpainted, new ones will stick out like a tarantula on a slice of fairy cake. (That was Raymond Chandler not me, I was going to say chapel hat pegs)!

Draught Proofing

There’s not much point in being the envy of the street if the windows rattle like a skeleton in a dustbin and there’s a George Raft howling into the room.

When the sashes are out, have grooves routered all round the edges and fit draught proofing strips. This applies to normal casement windows as well. Don’t mess around with adhesive ones, they work for a while then fall apart. He will have to determine “the fit” firstly though. If a particular casement is a tight fit then unless he shaves some off first, when he fits the insulation, the thing won’t move at all.

Secondary Glazing,

Secondary glazing cuts out noise and stops draughts, so your heating bills should drop. It is effectively a completely separate “window” fitted on the room side of the normal one. If you fit secondary glazing, don’t use Perspex, it deteriorates over time and you’ll think you’ve got cataracts. Decide which windows you open regularly and fit
sliding secondary glazing there. If you never open a particular window just get it permanently fixed, it’s cheaper. Remember to clean fixed secondary glazing thoroughly first though, plus the original window, or you’ll be looking at that smear for the rest of your life!

Do not allow a fire escape route to be blocked by permanent secondary glazing. You won’t be able to smash it, even if you can
find it, in the smoke filled horror of a fire.

Questions to ask the builder during his quotation visit.

How will you get the paint off?
Will his price reflect the acid / scraping methods (more expensive).

Have you burned paint off before?
A lot of builders have never done it, it’s a painter's job and painters don’t renovate windows. It is very easy to burn and ruin mouldings etc.

Have you ever used 2 part filler?
Experience is a definite boon here.

Have you ever increased a window’s glazing rebates with a router?
He won’t have!

Will you paint them afterwards?
Get the whole job done by one firm, it cuts out a lot of hassle.

Has he got the six weeks to spare that the job will take?
This last question is really quite relevant. We aren’t talking just preparing normal casement windows for painting, this happens all the time.

We are describing the complete dismantling of Victorian sash windows, burning all the paint from the casements and frame, sanding everything smooth, probably replacing the glass, rebating in new draught excluder strips, fitting heavier weights, fitting new cords, fitting proper catches and security locks, reassembling the whole thing, making sure it slides perfectly then waxing the whole lot.

That’s a lot of work/your money!

That’s assuming there’s no wood to replace because if there is, either the filler or the new wood will show, so the whole lot will then have to be painted.

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