How much do timber sash windows cost in London?

A smaller timber sash window can be a more affordable starting point than many homeowners expect. In one recent London quotation, an 800 × 1200 mm double glazed sash window was priced at £714 excluding VAT, supply only. That gives a useful reference for planning a project, although every bespoke window needs a quotation based on its own dimensions and specification.

Larger windows, decorative glazing bars and more detailed joinery increase the price. The important point is to compare windows of a similar size and construction, and to check whether the figure includes VAT, delivery and fitting. A supply only price and a fully installed sash window price cover different amounts of work. Timber sash window prices in London The following examples come from a recent quotation for bespoke timber sash windows. They show how the price changes between different sizes and specifications, rather than suggesting that every window of a particular size will cost the same. Example window size Price per window, excluding VAT 800 × 1200 mm £714.00 900 × 1700 mm £1,053.01 900 × 1800 mm £1,109.82 1200 × 1700 mm, with decorative details £1,666.89

These are supply only prices. VAT, delivery and installation are additional. The larger decorative example included glazing bars and an allowance for shaped joinery, so its price reflects more than the increase in width alone.

For the smaller example, £714 excluding VAT becomes £856.80 including VAT at 20%, before delivery or fitting. Showing both figures helps homeowners understand the starting cost without confusing the window price with the complete replacement budget.

If you are researching wooden sash window prices in London, use examples like these as a starting point for a discussion. Your own quotation should identify the actual window dimensions, opening arrangement, glass specification and finish. What changes the cost of a wooden sash window Size is one of the main factors, but it does not explain every difference between quotations. A larger sash needs more timber and glass, while the weight of the moving sections affects the balancing arrangement and hardware.

The design also matters. A straightforward rectangular sash window is different to a window with an arched head, decorative horns or glazing bars arranged to match an existing elevation. Reproducing the proportions of traditional windows requires attention to the frame, meeting rails and visible glass areas.

The timber specification influences the price too. Different timbers offer different characteristics, and the choice should suit the exposure, appearance and maintenance expectations of the property. Ask for the timber to be named in the quotation so you can compare offers accurately.

Paint finish is another detail to confirm. A quotation should state the colour and whether the same finish applies inside and outside. A photograph of a finished window is useful, but it does not replace a written specification.

When comparing bespoke sash windows in London, check:

• The overall frame dimensions.
• The timber and paint specification.
• The glazing and any safety glass.
• The balancing system and ironmongery.
• The glazing bar design.
• The cill and any ventilation.
• Whether the price covers a complete window or replacement sashes only. These details make a much more useful comparison than the headline price alone. Double glazed sash windows and everyday comfort Double glazing is an important part of the specification for many replacement timber sash windows. The examples above were quoted with a 4/16Ar/4 glass build up: two panes of glass separated by an argon filled cavity.

However, glass is only part of how a window performs. The frame construction, fit of the moving sashes, draught seals and installation all contribute to the finished result. A new double glazed sash window should be considered as a complete assembly.

For homeowners replacing old wooden sash windows, everyday improvements can include smoother operation, better fitting meeting rails and fewer draughts around the opening sections. The actual result depends on the window specification and how it is fitted.

If reducing traffic noise is a priority, discuss that before accepting a quotation. Standard double glazing and acoustic glazing are different specifications. A price for one should not be treated as a price for the other.

The same applies to thermal performance. Ask for the performance of the complete window where available, rather than relying only on a figure for the glass. This is particularly useful when comparing double glazed timber sash windows from different suppliers. Supply only and installed sash window costs A supply only quotation covers the manufacture and supply of the specified windows. It should not be read as the total cost of removing existing windows and fitting new ones.

Installation involves additional work that needs to be assessed at the property. The condition of the existing opening, access to the rooms and the amount of internal and external finishing can all affect the scope.

One important distinction is whether you are replacing the complete box frame or fitting new sashes into an existing frame. Retaining a sound frame may reduce the work involved, but it also means keeping part of the original construction. A complete replacement allows the frame and sashes to be specified together.

Neither approach should be assumed from the phrase “sash window replacement”. The quotation needs to say which one is included.

For a clear installed price, confirm whether the work covers:

• Removal and disposal of the existing windows.
• Fitting and securing the new frames.
• Insulation and sealing around the openings.
• Internal trims and external finishing.
• Making good to disturbed surfaces.
• Decoration after installation.
• Delivery and any special access arrangements. A clear scope helps you plan the full cost of replacing sash windows in London. It also reduces the chance of accepting a low initial figure and discovering that important work has been left out. Choosing where to spend your budget The most useful starting specification is one that meets the needs of the property without adding details you do not need. A simple rectangular timber sash window can still provide the traditional sliding operation and appearance that suit a period home.

Spend time on the proportions first. Frame widths, meeting rail positions and the arrangement of glazing bars affect how the window looks from both the street and the room. These choices are difficult to change once the window has been manufactured.

Then consider how each room is used. A bedroom overlooking a busy road may need a different glazing discussion from a room facing a quiet garden. An exposed elevation may also need particular attention to the finish and installation details.

If you are replacing several windows, ask for each opening to be priced separately. This makes it easier to see which windows account for the largest part of the budget and whether decorative features are increasing individual prices.

Avoid removing necessary details simply to reach a lower headline figure. Appropriate safety glass, suitable hardware and proper perimeter sealing are part of a usable window specification. Getting an accurate sash window quotation You can usually begin with photographs and approximate measurements. Include a photograph of the whole window from inside, a view from outside where practical, and close ups of any details you want to reproduce.

State whether you want a similar appearance or a change to the design. Mention glazing bars, paint colours, difficult access and any concerns about draughts, noise or operation.

If the property has planning or heritage restrictions, identify those at the quotation stage. Do not assume that every replacement detail will be acceptable simply because the new window is timber.

Windows Store Ltd can use this information to prepare an initial quotation and identify the details that need checking during a survey. Before an order goes into manufacture, the final dimensions and specification should be confirmed.

A useful quotation gives you more than a starting price. It tells you what is being made, what work is included and what the finished windows will provide for your home.