Box sash window repair, draught-proofing and restoration sit alongside internal doors, staircases and period joinery on this page, standard non-fire-rated work for London's Victorian and Edwardian terraces, distinct from the certificated fire doors covered on our dedicated fire doors page.
Brent overview
Sash Windows & Joinery in Brent
Home to the Wembley regeneration zone, with steady demand for property refurbishment and repairs across a mixed housing stock. Brent falls well within the West London ground Lian Construction covers on a regular basis. For sash window repair and restoration plus internal doors, staircases and period joinery in Brent, that local knowledge means fewer surprises once work is on site and a team that already understands the borough's typical property stock.
Brent's housing stock reflects its position as an outer West London borough that grew rapidly through the interwar period. Much of the borough is characterised by 1920s and 1930s semi-detached and terraced housing, built as London's suburbs expanded along the underground and mainline rail routes. Alongside this are pockets of earlier Victorian and Edwardian terraces closer to the borough's older centres, purpose-built mansion blocks and low-rise flats from the mid-20th century, and post-war council estates of varying scale and condition. More recently, the Wembley regeneration zone has brought a wave of new-build apartment blocks and mixed-use developments into the borough, sitting alongside the older housing rather than replacing it wholesale. This mix means Brent's properties span a wide range of construction methods and ages, from solid brick interwar semis needing damp, roofing or extension work, to newer flats where refurbishment tends to focus on interior fit-out and maintenance. For a contractor, this variety means jobs in Brent rarely follow a single template, and each property's age and construction type shapes the approach needed.
The Wembley regeneration zone has kept construction activity in Brent fairly constant, and that wider building boom tends to spill over into steady demand for refurbishment and repair work on existing homes nearby. Owners of older properties often want to bring their homes up to a similar standard as the new developments going in locally, whether that's a kitchen or bathroom refurbishment, re-roofing, or general repair work following years of deferred maintenance. Landlords in particular face pressure to keep older flats and houses competitive as newer rental stock comes onto the market through regeneration, which pushes many towards refurbishing rather than leaving units untouched between tenancies. Because Brent's housing stock is so mixed, demand isn't concentrated in one type of job: some homeowners need small repair work, others need larger structural or extension projects. This variety, combined with steady background demand from regeneration-driven activity, means there's consistent but not overwhelming work across the borough, without any single dominant type of renovation project standing out.
Typical sash window & joinery prices in London
Item
Typical range
Sash window draught-proofing, per window
£250–£450
Sash window restoration, per window
£400–£900
Bespoke like-for-like sash replacement, per window
£900–£1,600+
Internal door supply and fit, incl. lining
£250–£650
Staircase repair
£500–£2,500
General London market guidance, not a fixed quote — actual pricing depends on a site survey. Full breakdown: cost guide.
Building Regulations, Planning and Conservation Rules
Like-for-like sash window repair, and draught-proofing, don't generally trigger planning permission or Building Regulations, because you're not creating a new opening or materially altering the external appearance of the house. Full replacement of a sash window is a different matter on a freehold house not in a conservation area, permitted development rights usually allow like-for-like replacement without planning permission, provided the size and character of the opening doesn't change, but a flat has no permitted development rights of its own, so replacing windows in a converted Victorian house split into flats generally needs planning permission regardless of what the material is. Conservation areas add another layer: many London boroughs apply Article 4 directions specifically removing permitted development rights for windows on street-facing elevations, meaning even a straightforward timber-for-timber replacement can need planning permission, and a like-for-like timber sash with standard double glazing is often refused where it would visibly alter the glazing bar pattern or sightlines from the street. Slimline double glazing units, thin enough to fit the original timber rebate without altering the frame's profile, have a better track record of approval in conservation areas than standard double glazing, but every borough's conservation officer assesses this case by case, so it's worth checking with the local planning authority, or asking us to check on your behalf, before committing to a replacement sash rather than assuming a timber unit will automatically be approved. A staircase replacement that alters the pitch, going or rise of the stair, or changes the escape route from an upper floor, does fall under Building Regulations Approved Document K, and Building Control sign-off is needed; a like-for-like repair or refurbishment of an existing staircase generally doesn't.
Common Mistakes We Find in Previous Repairs
The single most common thing we find on a sash window that's been 'repaired' before is a synthetic cord or, worse, a length of nylon rope substituted for proper waxed sash cord, which stretches under the weight of the counterweight within a year or two and leaves the sash dropping again. Surface-mounted foam or brush strips stuck to the face of the staff bead rather than routed into a proper channel are another repeat finding, they look like draught-proofing but get painted over or peel off within a season and stop sealing properly. We also regularly find a sash simply painted shut rather than eased, which isn't a repair at all, and sills that have been patched with exterior filler rather than spliced with new timber, which looks fine for a year or two before the filler cracks and lets water straight back into the same spot. On the joinery side, the most common issue on staircases is a previous repair that's screwed straight down through the top of a tread into the riser below to stop a squeak, which usually doesn't address the actual cause, a loose wedge or glue block underneath, and just adds another failure point without fixing the movement that caused the squeak in the first place.
We diagnose whether a sticking or draughty sash is a paint build-up problem, a cord problem, or genuine timber rot before quoting a fix, so you're not paying for a full restoration when a service and re-hang would do.Sash cords are replaced with waxed sash cord matched to the original weight-and-pulley system, not cut down to a cheaper synthetic cord that stretches and needs redoing within a couple of years.Draught-proofing uses routed-in brush pile seals in the staff bead and parting bead, not surface-mounted foam strips that get painted over and stop sealing within a season.Regular coverage of Brent and the wider West London area
Signs to look for
Do you need sash windows & joinery in Brent?
Flaking paint or soft, spongy timber at the sill or bottom rail, especially on a south or west-facing elevation that gets more weather.
A rattling noise in wind, which usually means the sashes have shrunk slightly in their box and need easing or draught-proofing rather than replacing.
Condensation forming between the sashes on a cold morning, which is common on original single glazing and doesn't necessarily mean the window has failed.
A staircase tread that visibly flexes or bounces underfoot, not just squeaks, which suggests a structural fixing has failed rather than just a loose wedge.
How the work is handled in Brent
Step 1Survey each window, door or staircase element individually rather than quoting a blanket per-item price.
Step 2Test sash mechanisms, probe timber for rot, and check staircase fixings from underneath where access allows.
Step 3Confirm conservation area status, Article 4 directions and, for flats, whether freeholder consent is needed before agreeing scope.
Step 4Provide a written, itemised quote broken down by window, door or staircase element and repair type.
Step 5Order matched materials, waxed sash cord, brush-pile seals, period door profiles or matched skirting, ahead of the site visit.
Step 6Carry out repairs in the sequence that suits the wider project, windows and staircases before final decoration, doors after flooring.
Step 7Splice in new timber where rot is found rather than filling over it, then prime and undercoat before final paint.
Step 8Test every sash, door and stair fixing on completion before calling the job finished.
Step 9Leave the property clean, with offcuts and old materials removed, and photograph completed work for your records.
Questions
Sash Windows & Joinery questions in Brent
How quickly can Lian start sash window repair and restoration plus internal doors, staircases and period joinery in Brent?
Brent is part of our regular West London coverage, so once we've surveyed the property we can usually confirm a start date quickly. Send the address and scope and we'll arrange the next step.
Do you cover all of Brent?
Yes. Brent falls within the area Lian Construction serves across Greater London.
Do you take on jobs in Brent, including areas close to the Wembley regeneration zone?
Yes, we cover Brent as part of our wider West London coverage. Areas near the Wembley regeneration zone tend to have a mix of established housing and newer developments, so we're used to working alongside ongoing local building activity. If your property is close to an active regeneration site, it's worth flagging early, as access and parking can sometimes be more restricted than usual, and we'll factor that into scheduling and quoting.
How much does sash window draught-proofing cost in London?
Brush-pile draught-proofing to an existing sash in reasonable condition typically costs £250–£450 per window in London, reflecting higher labour and access costs than the £150–£350 seen in much of the rest of the country. It's usually the single fastest-payback measure on this page, since a properly sealed sash noticeably cuts draughts and heat loss for a fraction of the cost of a fuller restoration or replacement.
How much does full sash window restoration cost per window?
A fuller restoration, new sash cords, easing and re-hanging, re-puttying and draught-proofing where the timber itself is sound, typically costs £400–£900 per window. Where rot has to be cut out and spliced with new timber, add roughly £150–£250 per repair on top. A bespoke like-for-like replacement sash, where the existing frame is too far gone to repair, runs £900–£1,600 or more per window.
Can I replace my sash windows with double glazing in a conservation area?
It depends on the borough and the specific elevation. Many London councils accept slimline double-glazed timber sashes that closely match the original glazing bar pattern and sightlines, particularly on rear elevations, but standard double glazing is often refused on a street-facing elevation in a conservation area, and Article 4 directions in many boroughs remove permitted development rights that would otherwise allow a like-for-like swap without planning permission. Check with the local planning authority, or ask us to check on your behalf, before committing to a replacement.
Talk to Lian Construction about Brent
Send the site address in Brent, photos if available, and the sash windows & joinery work you need. We can review the scope and arrange the next step.