We carry out all listed building and conservation area sash work across London. Every job is different, so we treat each one case by case, because no two buildings share the same rules. We repair original timber wherever we can, match what we cannot save, and back our labour with a five-year guarantee.
Why listed sash windows need a different approach
However, on a listed building, the windows are part of what makes the building special. The glazing bars, the glass and the proportions all matter. So the aim is to keep as much original fabric as possible.
That is why we start with repair. Since our approach to sash window repairs already favours the original joinery, we only replace sections that have rotted or perished, and we shape new timber to match.
The law also pushes in this direction. The Planning (Listed Buildings and Conservation Areas) Act 1990 bars anyone from altering a listed building in a way that affects its character without authorisation. Breaking that rule is a criminal offence. As a result, it pays to check before you order any work.
Check consent before work starts
Rules differ from one building to the next. However, replacing windows or changing the glazing is more likely to need consent than careful repair, but the council decides each case. Your local council makes that decision, not us.
First, find out whether your home is listed and which grade it holds. Then speak to the conservation officer at your borough council. They can tell you which work needs consent.
We are happy to describe the work in plain terms, so your application reads clearly. For example, our guide to sash windows in London conservation areas covers the wider rules for homes that are not listed.
What we do on listed and conservation homes
We offer the same services as on any home, adapted to suit the building. For example, we repair sashes, frames and defective timber, and we reuse existing joinery wherever possible. We fit new sections only where the old timber has perished.
We also fit new sash cords and parting beads as part of an overhaul. In addition, we can draught proof without changing the look of the window. Nylon brush pile seals sit within the frame, so you can hardly see them from the street.
However, where the sill has failed, we splice first. Our sill repairs page explains when a full sill replacement becomes necessary.
Double glazing on a listed building
Double glazing is the hardest question on a listed home. Councils differ on it, and some allow it only in certain forms. Therefore we never assume the council will agree.
Our article on double glazing listed sash windows explains the options and the questions to ask your council. While that decision rests with the council, if it says yes, double glazing your existing sashes keeps the original timber. That is usually kinder to the building than a full replacement.
Instead, draught proofing is often the better first step. It stops rattles and draughts without touching the glass. As a result, many owners of listed homes start there.
Glass, finish and detail
Original glass has a character that modern glass cannot copy. Because of that, we avoid replacing old panes unless they crack or turn unsafe. When glass must change, we can supply any glass in the Pilkington range. Our glass replacement page lists the standard options.
We also match the finish to the building, because a bright new finish can stand out. We can supply timber primed, undercoated or with a full gloss finish on request. Then the new work blends in with the old.
Costs on listed work
Because every building differs, we do not publish a fixed price for listed jobs. The figure depends on the building, the access and the consent route. However, our standard rates on the costs page give a starting point.
For example, an overhaul and draught proof is £188 per window, and a sill replacement is £120 per window. Listed constraints can change those figures, so we confirm everything in a free written quote.
How a listed job runs
First, we visit and look at every window. We note the condition of the timber, the glass and the ironmongery, and we photograph anything unusual. Then we write up a repair plan that keeps as much original material as possible.
Next, you can share that plan with your conservation officer if you need consent. Once you have an answer, we agree dates and start work. However, we keep you informed if we find hidden damage, so there are no surprises.
Talk to us first
So tell us early if your home is listed or in a conservation area. We visit, look at the windows and explain what we can do. Although the visit and written quote are free, there is no obligation to go ahead.
To start, contact us with your postcode and a few photos. We cover all Greater London postcodes. We are open Monday to Friday, 08:00 to 18:00.