WhatsApp us
Sash window specialists covering Kent, London & the South East · We’ll beat any written quote ★ 5.0 on Google · 84 reviews Mon–Fri 9am–5pm
Advanced Sash Windows logoADVANCED SASH
WINDOWS
Sash window specialists · Maidstone
01622 470019

Replacement sash windows, made to match

Made-to-measure timber box sashes for the windows that genuinely cannot be saved — and an honest repair quote for the ones that can.

Get a free quote Call 01622 470019
★★★★★ 5.0 from 84 Google reviews We’ll beat any like-for-like written quote Insured to £5m · 10-year draught-proofing guarantee · free survey
New timber spliced into a sash window where the original was beyond saving
Repairs spliced in and primed

We only replace a sash window when it cannot be repaired. When it genuinely cannot, we make a new one to match the original — same sightlines, same horns, same glazing bars — rather than fitting a stock window that gives the elevation away. Free survey, written quote, 10-year draught-proofing guarantee.

Repair first, replace last

Most of the windows we are called out to look at have been quoted for replacement by someone else. A rotten sill, a split rail, a dropped sash or seventy years of paint are all repairs, and a repaired original outlasts most modern replacements because the timber in it is slow-grown. We will say so at the survey, even though the repair is the smaller job.

  • Rotten sill, rail, stile or horn — spliced, from £80 + VAT per section
  • Sash dropped or stuck — new cords and re-balancing, £250 + VAT per window
  • Painted shut — freed off and made to work, £100 + VAT
  • Everything tired at once — full restoration, £1,280 + VAT per window
  • Box frame gone, or the window is not the original — then a new sash is the honest answer

How a made-to-measure sash is built

Measured and templated

We measure the opening and record the profiles off the window coming out — horn shape, bar width, meeting rail, putty line.

Made in timber to suit

Engineered or accoya-grade timber for exposed elevations, softwood where it is sheltered and painted. Specified in the quote, not left vague.

Cords and weights, not springs

New box sashes are hung on cords, pulleys and weights the way the original was, so they behave the same and can be serviced in twenty years.

Glazed as agreed

Single glass to match a conservation condition, or slim double glazed units where they are permitted.

Fitted and made good

Old window out, new one in, plaster and brickwork made good, and the sash demonstrated working before we leave.

Guaranteed in writing

Draught-proofing is guaranteed for 10 years and all other workmanship for 1 year, and we are insured to £5m.

Listed buildings and conservation areas

Most of Kent’s period streets sit in a conservation area, and a lot of what we work on is listed. Replacing a window in either case is a planning matter, not just a joinery one — like-for-like replacement is treated very differently from a change of material or glazing. We tell you where you stand before any work is agreed, and we can supply the detail drawings and specification your application needs.

Replacement questions

When is a sash window beyond repair?

When the box frame itself has gone — not the sill or a rail, but the pulley stiles and head rotted through — or when a previous owner has replaced the original with something that was never a sash. Rot in a sill, a bottom rail, a stile or a cill horn is a repair, and repairs start at £80 + VAT per section.

Will a new window look like the original?

That is the point of a made-to-measure sash. We copy the sightlines, the horn profile, the glazing bar widths and the meeting rail from the window coming out, so from the street the elevation reads the same.

Can replacements be double glazed?

Yes. New sashes can be made for slim double glazed units, which is the sensible choice when the window is new anyway. We will tell you what the conservation position is for your address before you commit.

Do you replace one window or the whole house?

Either. Most jobs are a mix: two windows past saving, the rest repaired and draught-proofed. We quote each window separately so you can see exactly what you are paying for.

How much do replacement sash windows cost?

It is priced per window after a free survey, because the size, the glazing, the timber and the number of panes all change the figure. Repairs are published: £280 + VAT draught-proofing, £250 + VAT sash cords, £1,280 + VAT full restoration. Replacement is quoted in writing and we will beat any genuine like-for-like written quote.

Warmer, quieter windows that open properly. Free survey, fixed quote — and we’ll beat any like-for-like written quote.
Get a free quote Call 01622 470019 WhatsApp us