Sash, casement, bifold and French doors. Timber, aluminium and uPVC. Free site visits, written quote.
Windows and doors are where a London home loses most of its heat and most of its character. Get them right and the house is warmer, quieter and worth more — get them wrong and you've thrown good money at a problem you'll still have. TrustBuilt Projects installs the full range: traditional timber sash windows for period properties, slim aluminium casements and bifolds for contemporary extensions, uPVC for budget-conscious replacement schemes, and solid timber or composite entrance doors. We handle the survey, the removal of the existing units, the make-good of brick reveals and plaster, the new install, the trickle vents, the weather-sealing, and the internal and external finishing. Windows are installed to current Building Regulations Part L (thermal performance) and Part Q (security for ground-floor and accessible units), with double or triple glazing as specified. On conservation-area and listed properties we work with timber specialists to match existing profiles — slim sightlines, traditional putty lines, single-pane heritage glazing where required — rather than dropping in something that ruins the elevation.
We cover all of London within 20 miles of centre — Victorian sash work in Islington, Camden and Wandsworth, aluminium bifold sets onto garden extensions in Clapham and Dulwich, and full house replacements in the suburbs. The first step is always a free site visit so we can measure properly, check the reveals and lintels, and talk you through the realistic options. You get a written quote after — never a number before we've seen the openings.
We visit your property, assess the work needed, and listen to your priorities.
Itemised quote in writing within 48 hours of the visit.
Our team carries out the work. Daily progress updates if you want them.
Final walkthrough, snagging, full clean. We leave your home spotless.
It depends on the window type — uPVC casements cost less than timber sash windows, which vary with size and profile, and aluminium bifold doors are priced per linear metre. We provide a written quote after the free site visit.
Most windows go in at a rate of 2 to 4 per day per fitter. A whole-house replacement on a 3-bed terrace usually takes 4 to 7 working days. A single bifold door set is normally 1 to 2 days including make-good. We seal openings at the end of each day so the house stays watertight and secure overnight.
Like-for-like window replacement is normally permitted development. Planning permission is required for listed buildings, properties in conservation areas where there are Article 4 directions, and any change that alters the external appearance — for example switching from timber sash to uPVC casement, or enlarging an opening. We'll advise at the site visit and can submit applications where needed.
Yes — bespoke timber sash windows can be made to match existing profiles, horn shapes, glazing-bar patterns and meeting rail details. Slim double-glazing units (around 11mm overall) keep the heritage look while delivering modern thermal performance. On listed properties we specify the appropriate glazing and finish to match conservation officer requirements.
Timber for period properties and where appearance matters — needs repainting every 8 to 12 years but lasts decades. Aluminium for modern extensions, slim sightlines and large openings (bifolds, sliders) — low maintenance, premium price. uPVC for budget-conscious whole-house replacements on non-period homes — cheapest option, around 25 to 30 year lifespan. We'll talk through what makes sense for your home at the site visit.
Replacement glazing is a Building Regulations matter and certified self-installers can self-notify. Where the work falls under a competent-person scheme, we use specialist installers who are registered under the relevant scheme so the certificate is issued direct to you on completion. We'll confirm the route for your specific job at the quoting stage.
Yes — that's a structural job, not just a window job. We design the steel (engineer-calculated RSJ or pair of beams) to take the load, knock through, install the bifold set, and make good inside and out. Most rear-garden bifold openings on a London terrace take 2 to 3 weeks all in. Building Regs sign-off comes with it.
Bespoke timber sash windows and traditional joinery to match original profiles.
Learn more →Bifold and slider sets onto garden extensions, designed and installed as one job.
Learn more →Roof repairs, re-roofs and lead work to keep the rest of the house weathertight.
Learn more →Free site visit, no obligation, all London areas.
Book Your Free Visit →Every project is priced individually — we give you a fixed written quote after a free site visit.
uPVC is the most affordable; aluminium and especially timber (softwood, hardwood, Accoya) cost considerably more per window for the same opening.
Sliding sash units typically run around 50% more than an equivalent casement because of the more complex mechanism, weights and tighter machining.
Double versus triple glazing, acoustic glass, low-E coatings, toughened or laminated panes and Georgian bars all add to the per-unit price.
Many London boroughs require timber sashes or slimline heritage glazing to match the original, pushing material and approval costs up significantly.
New lintels, widening openings for bi-folds, upper-floor scaffolding and making good plaster or brickwork are extra and can be the largest line item.
Replacing a full house of windows at once lowers the per-unit rate; one-off replacements carry higher relative survey, delivery and labour costs.
Want an exact figure for your project? Book a free site visit → and we’ll send a written quote.