Bromley · Greater London
Bay window subsidence repairs in Bromley
Front gardens across Bromley and Greater London often put hedges, trees and gullies close to the bay. Each can affect the ground under a shallow bay footing, so they are checked before deciding between a tie-in repair and underpinning.
Guide price from£750per bay inc VAT
- Postcodes
- BR1, BR2, BR4, BR5, BR6
- Population
- about 330,000
- Area
- Greater London
- Pricing region
- London
What should you know about the ground under Bromley?
Bromley is one of the 32 London boroughs, with around 330,000 residents in districts such as BR1, BR2, BR4, BR5, BR6. We also take enquiries from nearby Swanley (5 miles), Lewisham (5 miles) and Croydon (6 miles).
Much of Greater London 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. Housing stock in Greater London: Victorian and Edwardian terraces with shallow footings, inter-war semis in the outer boroughs, and converted flats and mansion blocks.
What happens when we carry out bay window subsidence repairs in Bromley?
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 roof or lead flashing pulling away from the main wall
- A step or slope in the bay floor towards the window
- A vertical crack where the bay meets the front wall
How much will bay window subsidence repairs cost in Bromley?
These are guide prices for Bromley, using London 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. | £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 |
Which repair method suits a home in Bromley?
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
Traditional underpinning of the bay
The bay footing is excavated in short sections and new mass concrete is placed down to firmer ground below the zone affected by roots and seasons. Because a bay is a short length of wall, the work is compact, but it needs building control approval.
Best for: Active bay movement on firm ground at moderate depth
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 Bromley: questions and answers
How much should I budget for bay window subsidence repairs in Bromley?
Guide prices for bay window subsidence repairs in Bromley 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.
Can you survey a property in Bromley?
We do. Bromley and the surrounding area are covered, including nearby Swanley and Lewisham. A free initial assessment from your photos is the first step.
Why do houses in Greater London crack?
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.
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.
Will the bay window need replacing?
Usually not. Most windows can be eased, packed or resealed once the bay is stable. If the frame has twisted badly or the glass has cracked, replacement may be worth considering. Under a claim, upgrades beyond like-for-like are normally priced separately.
Related work in Bromley
- Structural surveys and crack monitoring
- Chimney stack repairs
- Underpinning
- Bowing wall repairs
- Floor joist repairs
Bay window subsidence repairs near Bromley
If your insurer is handling a bay claim at your Bromley property, share the schedule and we will price the repair to it in writing.