If you’re pricing up work on a period property, it’s normal to feel a little stuck at the starting line. One company quotes £1,200, another says £3,000, and suddenly you’re wondering if you’ve missed something obvious.
So, how much do timber sash windows cost in real life, for real homes, and what’s actually sitting behind the numbers?
This guide breaks down typical UK cost ranges, the choices that shift the price up or down, and the practical steps that help you budget confidently (without defaulting to “cheap and cheerful” alternatives that don’t suit a period property).
How much do timber sash windows cost today?
For most homeowners, the honest answer is: it depends on whether you’re replacing the full window (including the box frame), or replacing just the moving sashes while keeping the original frame.
At Wandsworth Sash Windows, we offer two routes – both built around authentic timber joinery, fully painted finishes, and double glazing.
1) Complete replacement (box frame + sashes)
This is the most comprehensive option. We remove and replace the entire box frame as well as the sashes. Everything is supplied fully painted and fitted with double-glazed glass.
- Starting price: around £2,000 + VAT per window, including installation.
This is typically the right fit when the existing frames are beyond economical repair, heavily distorted, rotten, or previously altered in a way that compromises performance.
2) Sash replacement (new sashes into the existing box frame)
This option retains the original box frame and replaces the moving parts only. New, fully painted, double-glazed sashes are fitted into the existing frame.
- Starting price: from £1,250 + VAT per window, including installation.
For many period homes, this can be the sweet spot – you keep the original frame (and the character that comes with it), while upgrading comfort, operation, and security.
Real-world cost ranges and what drives higher prices
When people ask “how much do timber sash windows cost”, they’re usually trying to understand two things at once: the base price, and the variables.
Here are some of the common factors that influence your final quote:
- Scope of replacement: full box replacement is more labour-intensive and involves more making good.
- Window size and configuration: bays, combinations, and larger openings take longer to manufacture and install.
- Glazing bar layout: a simple one-over-one design (no glazing bars) is typically more straightforward than multi-pane layouts.
- Access and logistics: upper floors, tight parking, or shared access can add time.
- Making good and redecorating: some work is to a pre-decorative standard (ready for painting/wallpaper by others), while other projects include more finishing.
A good quote shouldn’t just be a number; it should explain what you’re getting, what assumptions were made, and what happens if issues are discovered once the window is opened up.
Timber choices: understanding long-term value (not just the upfront cost)
Timber selection is one of the clearest “price levers” on sash windows and it’s also one of the biggest long-term performance decisions.
Regardless of which timber you choose, all our work comes with a 10-year guarantee for peace of mind.
Redwood (softwood)
Redwood is our starting option. It’s a quality softwood choice that suits many projects where you want traditional joinery and a sensible budget.
Utile hardwood (our typical hardwood)
Utile is the typical hardwood we offer. We often advise Utile because our workshop manager finds it takes paint particularly well compared to other hardwoods.
- Typical uplift: around +10%.
Accoya
Accoya is a branded timber that’s chemically treated for added longevity. The manufacturer provides a 50-year guarantee on the wood itself.
- Typical uplift: around +20%.
A quick note on what we don’t offer
We don’t offer pine or oak. If you’re comparing quotes and a competitor is pricing those timbers, it’s worth considering how that aligns with durability, maintenance expectations, and your property’s needs.
Supply-only vs supply-and-installation
Some companies offer supply only. That can look cheaper on paper because the customer arranges installation separately (often through a main contractor or builder).
At Wandsworth Sash Windows, we don’t offer a supply-only option as we do the full service: supply and installation.
There are practical reasons for that:
- We take pride in our joinery, and we want the finished result in your home to reflect that.
- General tradespeople may not fit sash windows correctly, which can lead to sticking sashes, draughts, poor sealing, and a frustrating overall experience.
- Our sash window fitters are full-time employees. If we took on lots of supply-only work, we’d have nothing for them to do.
In short: with sash windows, the install is part of the product.
Glass upgrade options (when standard double glazing isn’t enough)
Double glazing is included in both replacement routes, but some homes need a little more.
Acoustic glass
If you’re on a busy road, near a school, or simply want quieter rooms, acoustic glass can help. It typically uses a laminated outer pane to increase the barrier against noise.
Vacuum-insulated glass
Vacuum-insulated glazing is a newer technology. The benefit is that it can be ultra-slim while still offering very strong thermal performance, often compared to the efficiency of triple glazing.
Repair or replace: how to tell what your windows need
Not every sash window needs replacing. In many period properties, a good repair can restore operation and extend lifespan.
That said, replacement is often the more sensible route when:
- The box frame timber is extensively rotten or structurally weak.
- Previous alterations mean the sashes no longer sit properly, creating persistent draughts or rattling.
- The windows are difficult to use day-to-day, and repeated repairs have become a cycle.
If you’re unsure, it helps to approach it like a survey: understand what can be retained, what must be replaced, and what the long-term cost looks like either way.
Budgeting steps: a simple way to plan the project
If you’re trying to map out “how much do timber sash windows cost” for your home specifically, these steps keep things realistic:
- List every window and note floor level, access, and any bays.
- Decide the likely route per window: sash replacement vs full replacement.
- Choose your timber baseline (Redwood / Utile / Accoya).
- Decide on glazing upgrades only where they matter (traffic-facing rooms, bedrooms, nurseries).
- Plan for making good and redecorating, especially if full frames are being removed.
Setting expectations: manufacturing lead time and installation
Our manufacturing lead time varies, so it’s best to contact us for the current estimate.
Importantly, production lead time only starts once:
- We’ve received a deposit.
- You’ve confirmed and signed your specification online.
- We’ve completed a joinery survey visit to measure up in full.
Until those steps are complete, the manufacturing clock doesn’t start ticking.
Once the windows are made, we usually aim to install within 1–2 weeks, depending on your availability.
Setting expectations: disruption during installation
Disruption depends on which service you choose.
For both options, we ask that you remove window dressings (curtains/blinds) in advance and prepare a clear space of 1-2 metres in front of the window.
Sash replacement: lower disruption
With sash replacement, we only disturb a small area around the inside of the frame (by removing the staff bead). Follow-on work is usually minimal. Some clients choose to repaint existing frames afterwards if they haven’t opted for us to do this as part of the service.
Complete replacement: more extensive
Full replacement means the entire frames come out, which can be dusty (we protect the surrounding areas carefully). You may need to have radiators removed in advance. Any plasterwork making good is done to a pre-decorative standard, ready for painting or wallpaper by others.
Every property is different, so we recommend speaking to us early with any questions and reading the guidance documents we send.
Setting expectations: aftercare and our 10-year guarantee
Our 10-year guarantee is there for peace of mind. Sometimes an issue crops up months or even years after installation.
We’re here to help. If you have concerns, contact us, and we’ll investigate and resolve where required. We don’t provide an emergency callout service, but we do look into concerns in a timely way.
Example projects: a simple pricing guide
Sometimes it helps to see the numbers in context. Here are a few recent examples.
Bloom Park Road, Fulham, SW6 (May 2025)
A small project fitting 3 pairs of sashes in a basement bay. Simple one-over-one design (no glazing bars). We also completely repainted the existing frames.
- Rough price: £5,000
Cathles Road, Clapham, SW12 (June 2025)
A larger project replacing all sash windows. Five windows had new sashes installed into existing frames (all one-over-one, no glazing bars). Three windows had complete replacement, including one double-combination box frame.
- Rough price: £17,500
Oswyth Road, Denmark Hill, SE5 (June 2024)
Two complete new box sash windows fitted to the first floor front (complete replacement service).
- Rough price: £5,750
How to compare quotes fairly
When you’re comparing prices, try not to compare “window vs window” in name only. Compare:
- What’s being replaced (sashes only vs full box)
- Timber type and finish
- Glazing specification (and any upgrades)
- What making good is included (and to what standard)
- Warranty and aftercare
You can also weigh up your replacement windows options.
Choose the right option for you
So, how much do timber sash windows cost? For typical period home projects, you’re usually looking at around £1,250 + VAT per window (sash replacement into an existing frame) or around £2,000 + VAT per window (complete replacement), before you factor in timber upgrades, access, configurations, and glazing enhancements.
If you’d like a tailored quote with clear options and honest advice on whether you should repair, replace sashes, or go for a full box replacement, get in touch with Wandsworth Sash Windows. We’ll talk you through the best route for your property and help you budget with confidence.