A Victorian terrace is the house type where the headline cost guide can mislead you most. On window count it is an ordinary mid-terrace, 8 to 10 openings, which on our cost by house size guide sits at around £6,500 fully fitted in uPVC. The catch is that most Victorian terraces have vertical sliding sash windows, not flat casements, and many fall inside a conservation area. Both push the real figure higher. This page sets out the 2026 numbers for each route, so you can find the one that matches your terrace before you take a single quote. To price your own sashes, use the sash window calculator.
What a Victorian terrace actually costs
The table below prices the three realistic routes per window, fully fitted. Which row applies to you depends on your windows and whether your street carries conservation restrictions. A terrace that already has casements, or is free to change style, can take the cheapest row. A terrace with original sashes on a protected front elevation is pushed up to the sash and timber rows.
| Route | Per window (fitted) | Best for |
|---|---|---|
| uPVC casement | £400 to £1,000 | Rear or unrestricted elevations |
| uPVC sash | £600 to £1,500 | Sash look without timber upkeep |
| Timber sash (slimline DG) | £1,330 to £2,850 | Conservation and front elevations |
Source: DGCC 2026 dataset, cross-checked against sashwindows.london, sashwindowsuk.com and scottjameswindows.co.uk.
Why a Victorian terrace costs more than the average terrace
Two things lift the bill. First, the sash mechanism. A vertical sliding sash has deep box frames, cords or spring balances and far more joinery than a flat casement, so even in uPVC it runs roughly double the casement rate. Second, conservation. A large share of Victorian terraces sit in conservation areas, and where an Article 4 direction is in force the council can refuse uPVC and obvious double glazing on the front elevation. That forces like-for-like timber or slimline heritage units, which carry a timber premium of 60 to 110% over uPVC. The cost rules and the planning rules pull in the same direction, which is why a Victorian terrace so often lands well above the plain mid-terrace figure.
Worked example: a four-window front, restored in timber sash
Take a common Hackney or Islington scenario: a two-bay terrace with four original sashes on a conservation front elevation and six plainer windows at the back. The four front sashes go in like-for-like timber with slimline double glazing at around £2,500 each, which is £10,000. The six rear windows, unrestricted, go in uPVC casement at around £650 each, which is £3,900. The total lands near £14,000, against roughly £6,500 if the whole house could take plain uPVC. The gap is the heritage premium, not overcharging, and it is worth knowing about before the surveyor arrives.
The mistake on a Victorian terrace is pricing the front and the back the same. Spend the timber money on the front where the street sees it and the conservation officer cares, and put sensible uPVC casements on the rear elevation nobody photographs. Done that way, a terrace costs a lot less than the all-timber quote some firms push.
Tom Bradley, FENSA-registered installer
Best Buy for a Victorian terrace
Where you have a free choice, uPVC sash Best Buy gives the period look at roughly half the timber price and with no repainting. Reserve timber sash It depends for the front elevation or wherever conservation rules demand it. Plain uPVC casement Worth it is the value pick anywhere the original style is not a casement and nobody is forcing the issue. If you are weighing the sash question, our sash windows guide walks through the styles and mechanisms in full.
Frequently asked questions
If plain casement windows are allowed, a Victorian mid-terrace with 8 to 10 windows costs around £6,500 fully fitted in uPVC, within a £4,000 to £10,000 range. Most Victorian terraces have vertical sliding sashes, which cost more: roughly £600 to £1,500 per window in uPVC sash and £1,330 to £2,850 in timber sash, so a full house can run £18,000 to £30,000 in like-for-like timber.
Usually yes, unless the house is listed or sits in a conservation area with an Article 4 direction. Where Article 4 applies, uPVC and obvious double glazing are often refused on the front elevation, and like-for-like timber or slimline heritage units are required instead.
A sash window has a sliding mechanism, deeper box frames, cords or spring balances and far more joinery than a flat casement. That extra complexity, plus the heritage detailing many Victorian terraces need, is what lifts the per-window price well above the uPVC casement floor.
It can be the only way to get double glazing approved on a restricted front elevation, because the slim sightline matches the original glazing bars. A full sash refurbishment with slimline units, factory finish and new ironmongery runs around £3,900 to £5,400 plus VAT for a part-house package.
Yes. A FENSA-registered installer self-certifies the work against Building Regulations without separate council sign-off. On a conservation or sash job, also confirm the installer has done period work before, because the heritage detailing is where inexperienced fitters get it wrong.