Greenwich · Greater London
Bay window subsidence repairs in Greenwich
If your Greenwich bay window has started sticking and a gap has opened at the junction, it is worth finding out whether the bay is still moving. A stable crack needs a straightforward tie-in, whereas an active one may need a new foundation.
Guide price from£750per bay inc VAT
- Postcodes
- SE3, SE7, SE9, SE10, SE18
- Population
- about 290,000
- Area
- Greater London
- Pricing region
- London
Why does the ground in Greater London matter for bay window subsidence repairs?
Greenwich takes in postcode districts including SE3, SE7, SE9, SE10, SE18, with about 290,000 residents. Nearby places we cover include Lewisham (4 miles), Newham (4 miles) and Bexley (4 miles).
Shrinkable clay is widespread in Greater London. Ground movement here is more often linked to soils, drains and trees than to mining. Typical buildings in Greater London: Victorian and Edwardian terraces with shallow footings, inter-war semis in the outer boroughs, and converted flats and mansion blocks.
Symptoms that point to bay window subsidence repairs
- Gaps opening around the internal bay window board
- Cracks above the bay window head or below the sill
- A vertical crack where the bay meets the front wall
Guide prices for bay window subsidence repairs in Greenwich
The ranges below reflect typical London costs for bay window subsidence repairs, including VAT. Scaffold, access and making good can push a job to the top of the range.
| Item | Guide price | Per |
|---|---|---|
| Bay junction crack repair and tie-inest. | £750 – £2,250 | per bay |
| Traditional underpinning of a bay | £3,750 – £8,750 | per bay |
| Mini-piled bay underpinning | £6,250 – £15,000 | per bay |
Methods for 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
From first photo to finished repair
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.
Make good inside
Plaster around the bay and along the junction is renewed, the window board is refixed and the room is ready for decoration. Building control paperwork, where it applies, is passed to you for your records.
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.
Frequently asked questions
How much will bay window subsidence repairs cost in Greenwich?
Guide prices for bay window subsidence repairs in Greenwich start from about £750 per bay, including VAT, on London rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Greenwich?
Yes, Greenwich is covered, along with postcode districts SE3, SE7, SE9, SE10. We also cover nearby Lewisham and Newham.
Is the ground in Greater London prone to subsidence?
Most of Greater London sits on London Clay, among the most shrinkage-prone ground in the UK, with river gravels along the Thames. Subsidence claims here are among the most frequent in the country, especially after dry summers and near street and garden 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.
Why do bay windows crack away from the house?
Bays often stand on shallower footings than the main walls, so they react to drying clay, roots and drain leaks that the deeper house foundations escape. Many bays were also never properly tied in, so any movement opens a clean vertical crack at the junction.
Other structural repairs in Greenwich
Bay window subsidence repairs near Greenwich
For a no-obligation written quote on bay window subsidence in Greenwich, call or send a few photos with a tape measure in shot.