How to Price Sash Window Restoration in the UK (2026 Guide)
Sash window restoration is a specialist, high-margin trade with strong demand from Victorian, Edwardian, and Georgian homeowners who want to preserve original features. The work ranges from simple draught-proofing and cord replacement through to full refurbishment with secondary glazing — and pricing varies enormously between these levels. This guide covers every scope of restoration work, pricing per window, labour hours, materials, conservation area considerations, and profit margins.
The range of sash window restoration work
Sash window restoration covers a wide spectrum of work, from minor repairs through to comprehensive refurbishment. At the lighter end, draught-proofing involves fitting a specialist brush or pile seal system into the window frame to eliminate cold air infiltration — a job that significantly improves thermal performance without altering the window appearance. Cord and weight replacement addresses broken or frayed sash cords that cause sashes to drop or become difficult to operate. Full refurbishment combines draught-proofing, cord and weight replacement, timber repairs (rotting sills, broken glazing bars, failed putty), repainting, and often the fitting of new hardware. Secondary glazing — an independent inner frame fitted behind the existing sash — provides near-double-glazing thermal performance without altering the external appearance, which is critical in conservation areas and listed buildings.
Pricing per window by type of work
Draught-proofing a single sash window using a quality pile seal system typically runs £200–400 per window supply and install, with the cost varying by window size and the accessibility of the parting bead and staff bead. Cord and weight replacement is typically £150–300 per window — both sashes, both sides. Combining draught-proofing and cord replacement in one visit is more efficient and should be priced at £300–550 per window rather than adding the two separate prices. A full refurbishment — including timber repairs, putty renewal, draught-proofing, cord and weight replacement, and priming ready for decoration — typically runs £500–1,200 per window depending on condition and size. Secondary glazing adds £400–900 per window depending on the system specified. On a typical Victorian terrace with 8–10 sash windows, a full restoration programme including secondary glazing can comfortably reach £8,000–14,000.
Labour hours per window
Labour estimation for sash restoration is more variable than most joinery work because window condition is hard to assess accurately before the job starts. As a baseline: draught-proofing alone takes 2–4 hours per window for a competent sash specialist. Cord replacement takes 1.5–3 hours per window depending on access to the weight pocket and the condition of the existing hardware. A full refurbishment including timber repairs takes 4–8 hours per window — more if the sashes need to be re-weighted, repaired sections need to cure, or if the window has been painted shut and requires significant preparation before the sash can be removed. Price labour at your current day rate (£180–280 per day for an experienced joiner or sash specialist) divided by the realistic hour count per window. Always include a contingency for windows that prove more difficult than they appear on survey — rot concealed by paint is the most common cause of scope overruns on restoration work.
Materials: cords, weights, putty, and draught-proofing systems
Sash restoration materials are relatively low-cost compared to labour, but specifying quality materials is important for client satisfaction and the longevity of your work. Sash cords should be waxed cotton or polypropylene — not the cheap cotton cord sold in hardware stores, which fails within 2–3 years. Draught-proofing systems from specialist suppliers (Ventrolla, The Sash Window Workshop systems, or independent equivalents) run £50–120 per window in materials for a quality pile or brush seal system. Weights may need replacing or supplementing if the existing cast iron weights are missing or insufficient for the sash. Linseed oil putty is the correct material for re-puttying traditional single-glazed sashes — modern acrylic frame sealants are not appropriate and will crack. Timber repair products (Repair Care, Ronseal High Performance Wood Filler, or similar) are used for localised rot repairs before priming. Materials on a typical full refurbishment run £80–200 per window at trade prices.
Property types: Victorian, Edwardian, Georgian
Sash window restoration demand concentrates in Victorian terraces (1837–1901), Edwardian semis and terraces (1901–1910), and Georgian townhouses and country houses (1714–1830). These periods account for a very large proportion of UK housing stock, particularly in cities like London, Bristol, Edinburgh, Manchester, and Leeds. Victorian and Edwardian properties typically have standard double-hung sliding sashes in softwood, while Georgian properties more often feature larger sashes in hardwood or heavier softwood with more complex mouldings and larger pane arrangements. Georgian windows require more care to restore and command higher per-window pricing. Clients in these properties are typically owner-occupiers who value original features and are willing to pay a specialist premium — they are not shopping on price in the same way as customers seeking replacement windows.
Planning consent and listed building considerations
In conservation areas, replacing original sash windows with uPVC or aluminium alternatives typically requires planning permission — which is why restoration is the default solution and why demand for restoration specialists is strong in these areas. Like-for-like repair and restoration of existing windows does not usually require planning consent in a conservation area, but fitting secondary glazing may require notification to the local authority in some designations. For listed buildings, any works to windows — including repair and restoration — may require listed building consent if they materially affect the character of the building. Advise clients in listed buildings to check with their local planning authority before specifying secondary glazing or any work beyond like-for-like repair. Being the specialist who understands these rules builds significant trust with conservation-area clients and differentiates you from generalist joiners and window companies.
Profit margins on specialist restoration work
Sash window restoration commands significantly higher margins than general joinery or window fitting because it is specialist work with limited competition and clients who are motivated by preserving their property rather than minimising cost. A well-run sash restoration business targets 40–60% gross margin on each project. Labour is the dominant cost; materials are a relatively small proportion of the total. Margins at the lower end of this range typically indicate under-pricing on draught-proofing or cord replacement jobs where the work appears simple — but the specialist knowledge, tools, and experience required justify a premium price. Clients who have had a poor experience with a generalist attempting sash restoration will pay significantly more for a proven specialist. Build your reputation on quality, back it with good photography and Google reviews, and charge accordingly.
Deposit structure for restoration projects
Sash restoration projects of three or more windows typically warrant a deposit of 30–40% before work begins to cover materials and secure the booking. For whole-house restoration programmes, a staged payment structure works well: 40% deposit on acceptance, 30% at the halfway point, and 30% on completion. For smaller jobs of one or two windows, payment in full on completion is standard practice. Always confirm the scope in writing before starting — a clear written quote specifying exactly which windows are included, what work will be done to each, and what is excluded (decoration, making good of paint around frames, for example) prevents the scope disputes that most commonly arise on multi-window restoration programmes.
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