Chichester · West Sussex
Bay window subsidence repairs in Chichester
Many bays in Chichester were butted against the house rather than bonded into it with ties or toothed brickwork. That makes the junction the first place any differential movement shows, even when the bay foundation is reasonably sound.
Guide price from£670per bay inc VAT

- Postcodes
- PO19
- Population
- about 32,000
- Area
- West Sussex
- Pricing region
- South East
Is West Sussex prone to ground movement?
We cover Chichester and its postcode districts PO19, part of West Sussex, with a population of roughly 32,000. We also take enquiries from nearby Bognor Regis (6 miles), Emsworth (7 miles) and Hayling Island (9 miles).
West Sussex is one of the parts of the UK where clay soils are most likely to move with the seasons. Ground movement here is more often linked to soils, drains and trees than to mining. Across West Sussex, most homes are Wealden cottages, 1930s semis and bungalows on the coast, and new-town estates in Crawley.
What to look for before calling about bay window subsidence repairs
- Bay window sash or casement sticking or binding
- A vertical crack where the bay meets the front wall
- A step or slope in the bay floor towards the window
Bay window subsidence repairs prices in Chichester
Prices in Chichester are worked out on South East rates. They include VAT and are a starting point: access, the extent of the damage and whether an engineer or building control is involved all move the figure.
| Item | Guide price | Per |
|---|---|---|
| Bay junction crack repair and tie-inest. | £670 – £2,000 | per bay |
| Traditional underpinning of a bay | £3,350 – £7,850 | per bay |
| Mini-piled bay underpinning | £5,600 – £13,400 | per bay |
How we usually approach bay window subsidence repairs
Junction crack repair and tie-in
Where movement has stopped, the open joint between bay and house is raked out, stainless ties or helical bars are fixed across it, and the joint is repointed to match. Internal plaster along the crack is cut back and renewed before redecoration.
Best for: Old, stable cracks where the bay is no longer moving
Mini-piled bay underpinning
Small piles are installed to depth around or beneath the bay and linked by a reinforced beam or needles that pick up its weight. It suits deeper soft ground and heavy root activity, and the compact rigs fit into a front garden.
Best for: Deep clay, nearby trees, or poor ground below the bay
What happens during bay window subsidence repairs, step by step?
Engineer and checks
Where the cause is unclear, an independent chartered structural engineer inspects, sometimes with a trial pit at the bay and a drain survey. We can arrange the engineer. Monitoring may be suggested if the movement could be seasonal.
Agree the repair
The engineer decides between tie-in repairs and underpinning. We confirm a fixed price in writing once the repair is specified, including scaffolding if needed, the bay window, roof flashing and internal making good.
Carry out the work
Ties are fitted across the junction, or the bay is underpinned in sequence with building control inspecting the dig. The bay window and flashings are checked and eased or resealed where the movement has disturbed them.
Rules for bay window subsidence repairs in England
In England, underpinning and other work that alters or strengthens a wall or foundation is building work under the Building Regulations (Part A, structure), so building control approves and inspects it. Like-for-like repairs often are not, and we tell you which applies before a price is agreed. Work to a party wall, or excavation close to a neighbour’s foundations, can also need a notice under the Party Wall etc. Act 1996.
Questions about bay window subsidence repairs in Chichester
How much should I budget for bay window subsidence repairs in Chichester?
Guide prices for bay window subsidence repairs in Chichester start from about £670 per bay, including VAT, on South East rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Can you survey a property in Chichester?
We do. Chichester and the surrounding area are covered, including nearby Bognor Regis and Emsworth. A free initial assessment from your photos is the first step.
Why do houses in West Sussex crack?
North West Sussex around Crawley and Horsham sits on Weald Clay, the South Downs are chalk, and the coastal plain has brickearth and gravels. The Weald Clay is prone to shrink-swell movement near trees. Only an investigation can say why a particular building has moved.
Is a crack between my bay and the house serious?
It is often not serious, especially if it is old, fine and unchanged for years. A crack that is widening, tapering or matched by sticking windows and a sloping bay floor needs looking at. An engineer’s inspection, sometimes with monitoring, will confirm whether the bay is still moving.
Does a bay window always need underpinning?
No, many bays are fixed by tying the junction and repointing, once any cause such as a leaking gully is put right. Underpinning is for bays still dropping after the cause has been dealt with, or with footings too shallow for the ground they sit on.
Related work in Chichester
Bay window subsidence repairs near Chichester
If your insurer is handling a bay claim at your Chichester property, share the schedule and we will price the repair to it in writing.