Product
Sash Windows
Bespoke Timber Windows is a specialist sash windows manufacturer making timber sash windows to measure for homes across London and the Home Counties. A sash window has one or two glazed panels, called sashes, that slide vertically within the frame. We design, make and install wooden sash windows for period homes, conservation areas and new builds.
From £895
6–10 week lead time
Overview
Wooden Sash Windows Built for Your Home
Our wooden sash windows are made to measure in responsibly sourced softwood or hardwood, built around your opening, the age of your property and how you want the window to work. As a specialist sash windows manufacturer, Bespoke Timber Windows controls every stage, from the survey measurements to the final adjustment of the sashes.
Key Benefits
A timber sash window from Bespoke Timber Windows pairs the proportions of a period window with the glazing, seals and security a London home needs today. Each one is made to order in our Harrow workshop and factory-finished before it reaches you, so there is no painting or glazing to do on site.
Authentic Detailing
Mouldings, horns, meeting rails, glazing bars and cills made to suit the age and style of your property.
Quality Timber
Responsibly sourced softwood or hardwood, chosen to suit your property, budget and finish.
Double Glazing
Slimline or standard A-rated double glazing, or triple glazing, with draught-proofing built in and Part L compliance.
Secure Locking
Sash fasteners and locks suited to your property, internal beading as standard and PAS 24 security as an option.
Durable Finish
Factory-applied microporous paint or stain in a wide choice of colours, including heritage shades.
Made to Measure
Every timber sash window is built to fit your opening, never cut down from a stock size.
Get a price for your timber sash windows
Send us the size and number of windows for a free instant estimate. When you are ready, book a survey with a 10% deposit and we will measure every opening and confirm your price. The survey is free when you order, as the deposit comes straight off your total.
Specification
- Timber Options
- Softwood or Hardwood
- Glazing
- Double or Triple Glazed, 4mm–12mm cavities
- Finish Options
- Factory spray, brush paint, natural oil, stain
- Hardware
- Sash lift, fitch catch, locking sash lift
- Max Width
- 1,800mm
- Max Height
- 2,400mm
- Lead Time
- 6–10 weeks from survey
- Guarantee
- 10 years structural, 5 years finish
Colours & Finishes
Any RAL colour available. Internal and external colours can be different at no additional cost. Factory spray finish standard. All colours matched on site survey.
Glass Options for Timber Sash Windows
| # | Glass | Feature | U-Value |
|---|---|---|---|
| 1 | Double Glazed Standard high-performance double glazing with low-e coating and argon fill. | A-Rated | 1.2 W/m²K |
| 2 | Triple Glazed Maximum thermal performance. Ideal for exposed locations or eco-builds. | Best Thermal | 0.7 W/m²K |
| 3 | Acoustic Glass 44dB acoustic reduction with laminated inner pane. Perfect for urban streets. | 44dB Reduction | 1.2 W/m²K |
Timber vs uPVC Sash Windows
| Feature | Sash Windows (Timber) | uPVC Windows |
|---|---|---|
| Cost | Higher upfront investment, from £895 per window | Budget-friendly |
| Appearance | Authentic period look with true mouldings, horns and glazing bars | Modern; sash-style options available, usually with wider frames |
| Maintenance | Periodic repainting or re-staining of the factory finish | Wipe-clean, minimal upkeep |
| Energy Efficiency | U-values down to 0.7 W/m²K with triple glazing and draught-proofing | Good thermal performance; A-rated units widely available |
| Lifespan | 60+ years with proper care | 25–35 years |
| Repairs | Damaged sections can be cut out and replaced | Usually replaced as a whole unit |
| Property Value | Adds value, especially in period homes | Moderate boost |
| Best For | Listed, conservation-area and period properties | Modern homes and cost-conscious buyers |
Sash Windows Installation Across London and the Home Counties
Sash windows installation at Bespoke Timber Windows is carried out by our own fitters, never subcontractors, so the people who measure your home are the people who fit your windows. Installation follows 6–10 weeks after order confirmation, and as a FENSA registered installer we register the work with building control for you.
How we fit your sash windows:
-
Estimate: Send us your sizes for a free instant estimate, so you know the likely cost before you book anything.
-
Survey: We take a 10% deposit to book your survey, then measure each opening, check the reveals, cills and brickwork, and confirm your price. The deposit comes off your total when you order.
-
Manufacture: Your windows are made, glazed and factory-finished in our workshop.
-
Protect: We cover floors and furniture and protect the work area inside and out.
-
Remove and fit: We take out the old windows, fit the new frames square and level, and seal them to the masonry.
-
Make good and check: We make good the reveals, adjust each sash so it slides and locks smoothly, and leave the site tidy.
Architects and trade buyers can also order our timber sash windows on a supply-only basis.
Where we work
London and the Home Counties
London areas
Harrow · Pinner · Stanmore · Wembley · Northwood · Ealing · Barnet
Counties
Hertfordshire · Surrey · Essex · Kent · Buckinghamshire
Why Choose Bespoke Timber Windows for Your Sash Windows?
Bespoke Timber Windows makes wooden sash windows to measure in Harrow and fits them with its own team, so you deal with one company from survey to handover. We have been making windows since 2017, have installed more than 800, and hold a 4.9★ Google rating from more than 340 reviews.
As a specialist sash windows manufacturer, we make every part of your timber sash window ourselves, so we can advise on everything from the sliding sash window mechanism to the glazing and finish. Our own team carries out each sash windows installation, leaving your home tidy and your windows working smoothly. We are FENSA Registered and CERTASS Members.
-
Made for your home. Every sash window is made to order, with horns, glazing bars and mouldings matched to your property rather than adapted from a standard size.
-
Honest advice from the makers. We build the windows, so you get clear guidance on timber, glazing and finish from the people who make them, including when another window style would suit you better.
-
One team, start to finish. Survey, manufacture and installation are all handled by us, with no subcontractors.
Sash Windows FAQs
A sash window is a window with one or two glazed panels, called sashes, that slide vertically within the frame. It is a classic feature of Georgian, Victorian and Edwardian homes. Bespoke Timber Windows makes each sliding sash window to measure in timber, using either weights and cords or concealed balances.
A box sash uses weights and cords hidden in a boxed frame, while a spring sash uses concealed spring balances and typically has a slimmer frame. Box sashes give the most traditional look and feel, which suits listed buildings and conservation areas. Spring sashes suit most other homes and cost less to make.
Yes. Bespoke Timber Windows can replicate your existing profiles, glazing bar patterns, proportions, cills and ironmongery. We record the original details during the survey, then our own team handles the sash windows installation. If your home is listed, you will still need listed building consent from your council first.
Yes. Our wooden sash windows come with A-rated double glazing as standard, including slimline units that keep glazing bars slim on period homes. Triple glazing is also available, with U-values down to 0.7 W/m²K, and every window we supply meets Part L of the Building Regulations.
Well-made timber sash windows can last 60 years or more with proper care. Check the paintwork once a year and recoat when the factory finish starts to wear. Unlike uPVC, timber can be repaired in sections, so a rotten cill or damaged sash does not mean replacing the whole window.
If the frames are mostly sound, repair is often the better choice: rotten sections, cills and sash cords can be replaced and the windows draught-proofed. Replacement makes more sense when the timber is decayed throughout, or when you want double glazing and better security. We will look at your windows during the survey and tell you honestly which route suits them.
Ready for New Timber Sash Windows?
Speak to your local Harrow sash windows manufacturer for a clear quote on timber sash windows, made and fitted by one team. Call us on 020 8050 4987, Monday to Friday 8am–6pm and Saturday 9am–2pm, or request a quote online.
Related Products
You Might Also Like
Secure
Entrance Doors
Mortice-locked solid timber doors with multipoint hardware.
From £1,295
VIEW →
Best Value
Casement Windows
Side-hung, top-hung, and tilt-and-turn. Versatile designs for any elevation.
From £595
VIEW →
Light & Air
French Doors
Full-height glazed pairs opening inward or outward.
From £1,395
VIEW →
