Portsmouth · Hampshire
Bay window subsidence repairs in Portsmouth
Bay windows are a feature of many older streets in Portsmouth, and so is the crack where a bay meets the front wall. Often it reflects a shallower bay footing reacting to the ground, rather than a problem with the whole house.
Guide price from£670per bay inc VAT
- Postcodes
- PO1, PO2, PO5
- Population
- about 210,000
- Area
- Hampshire
- Pricing region
- South East
Is Hampshire prone to ground movement?
We cover Portsmouth and its postcode districts PO1, PO2, PO5, part of Hampshire, with a population of roughly 210,000. Nearby places we cover include Fareham (5 miles), Hayling Island (5 miles) and Havant (6 miles).
Much of Hampshire sits on clay that shrinks in dry summers and swells in wet winters. Ground movement here is more often linked to soils, drains and trees than to mining. Across Hampshire, most homes are Victorian terraces in Portsmouth and Southampton, 1930s semis, and large post-war and new-build estates.
How much will bay window subsidence repairs cost in Portsmouth?
These are guide prices for Portsmouth, using South East rates and including VAT. Your written quote follows photos or a survey, and is fixed once the repair is specified.
| 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 |
Which repair method suits a home in Portsmouth?
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 when we carry out bay window subsidence repairs in Portsmouth?
Photos and first view
Send photos of the outside junction, the inside corners and the window, with a scale. We give a free initial assessment and tell you whether the crack looks old and stable or whether an engineer should inspect first.
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.
Signs you may need bay window subsidence repairs
- Bay window sash or casement sticking or binding
- Gaps opening around the internal bay window board
- A step or slope in the bay floor towards the window
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.
Bay window subsidence repairs in Portsmouth: questions and answers
How much will bay window subsidence repairs cost in Portsmouth?
Guide prices for bay window subsidence repairs in Portsmouth 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.
Do you cover Portsmouth?
Yes. We take enquiries from across Portsmouth, including PO1, PO2, PO5, and from nearby places such as Fareham and Hayling Island. Send photos for a free initial view and we will tell you what happens next.
Is the ground in Hampshire prone to subsidence?
Central Hampshire is chalk, while the south around Portsmouth, Southampton and the New Forest fringe and the north-east around Farnborough sit on London Clay, Reading Beds and other clays and sands. The clay areas see seasonal 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.
How long does bay underpinning take?
Traditional underpinning of a bay usually takes about a week on site, and mini-piling a little longer depending on depth. A junction tie-in without underpinning normally takes one to two days. Approvals and any monitoring beforehand add to the overall timeline.
Other structural repairs in Portsmouth
- Extension pulling away repairs
- Subsidence repairs
- Brick arch repairs
- Retaining wall repairs
- Boundary and garden wall repairs
Bay window subsidence repairs near Portsmouth
If your insurer is handling a bay claim at your Portsmouth property, share the schedule and we will price the repair to it in writing.