Sash Replacement in Existing Box Frames, Prince of Wales Drive, Battersea, SW11
Job Value: £30,000 – £32,000 ex. VAT. Completed in October 2026
Survey
Our client was looking for advice on sash window replacement and other ways to improve the function, aesthetics and thermal efficiency of her windows.
Our client initially contacted us in April 2026 to arrange a visit for our surveyor Sean to attend her property to look at 15 sash windows and a set of French doors. The property is an apartment within the beautiful mansion blocks on Prince of Wales Drive in Battersea, which overlook Battersea Park. Construction of these large, Victorian red brick mansion blocks that form a near-mile-long row directly south of the park began in 1893. Most of the blocks were built by property developer Cyril Flower (1st Baron Battersea).
Why Sash Window Replacement
During Sean’s visit a couple of factors suggested that a sash replacement service would be best for the sash windows. Firstly, Sean noted that the existing box frames were in a good condition. This is generally the first aspect that we will inspect when carrying out a site survey on sash windows. The existing frames of box sash windows are usually in a good condition, because around 85% of the frame is tucked behind brickwork, which means that they are protected from the elements.
The other factor that was noted by Sean was that various windows had surrounds that could make a complete replacement a less favourable option. On most windows, there were deep square linings and window boards. These can be replaced, but it does add considerable time (and therefore cost) to the on-site installation. The kitchen worktop was butted right up to the cill of the kitchen window, which meant that completely replacing this window would have required the removal and reinstallation of the worktop, by others. This would again increase cost and complexity. A similar situation was the case with the bathroom windows, with large marble tiles butting right up to the window cill, and these would likely be damaged during the installation process.
The combination of these factors meant that we recommended the sash replacement service. Our client also requested that the existing plantation shutters were removed and disposed of by us as part of the works, and that the existing box frames were decorated by us during the works. Our guide to repairing or replacing sash windows explains how we make this decision.
For the French doors, it was deemed that a complete replacement of the doors and frame would be the best option. French door frames are different to sash windows, in that in most circumstances the frames are completely exposed beyond the brickwork and, without regular maintenance, can deteriorate more quickly.
Specification
The sash windows and doors were all glazed with 24mm toughened double glazed units, which were made up with two sheets of 4mm glass, either side of a 16mm Argon gas filled spacer.
Our client chose polished brass ironmongery supplied by Hardwick, and our standard clean white paint finish. We use Teknos Aquatop paint, which is spray applied to the joinery to give an immaculate finish. For the French doors, she also opted for Hardwick handles for the doors and fanlight, with a Winkhaus multipoint locking mechanism.
After visiting our showroom in Fulham our client also decided to add on the replacement of all existing pulley wheels.
As there were a number of additional services included, like the removal of the shutters, decoration of the existing frames and replacement of the pulley wheels, the price per window for the sash replacement service increased to around £1,700 to £1,800 per window exclusive of VAT. The French doors were priced around £5,000 exclusive of VAT.
Our client placed an order in mid-May and the final measurements were taken on site in late May.
Manufacture
The sash windows were manufactured at our workshop in East Sussex, overseen by our workshop manager Trevor.
The French doors were manufactured in our Warwickshire workshop, overseen by our workshop manager Craig.
Production was scheduled to finish on 14th August, but the client asked us to hold delivery until the end of September while other building work was carried out.
Installation
Nishan and Nitin, our installation team, began installing the new sashes and French doors on site on 1st October. Working alongside and around multiple other trades on site requires careful planning and organisation, so the trades don’t get in each other’s way. Nishan did a fantastic job of liaising with the main contractor and project manager on site to ensure this.
In total, the installation took 12 working days, with the works being completed on 16th October.
Result
The sash windows are now fully draught sealed, operating much more smoothly and freely. The new, double glazed sashes and French doors will make a real difference to the warmth of the apartment, and we are looking forward to the other building work being completed at the property, so our client can move in and make the most of the warmth that double glazing brings!
Following installation, the project manager stated that “Nish and his junior are a lovely pair of guys, and have done a fantastic job on site”. Our client said “Thank you, the windows look great”.
If you would like an on-site consultation with one of our expert surveyors to see what service is right for you, please contact us.
