Yeovil · Somerset
Bay window subsidence repairs in Yeovil
If your Yeovil 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£620per bay inc VAT

- Postcodes
- BA20, BA21
- Population
- about 50,000
- Area
- Somerset
- Pricing region
- South West
What should you know about the ground under Yeovil?
Yeovil is in Somerset and takes in postcode districts BA20, BA21. About 50,000 people live there. Nearby, we also cover Dorchester (18 miles), Bridgwater (21 miles) and Taunton (21 miles).
Clay soils are found in parts of Somerset. Parts of Somerset lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. Housing stock in Somerset: Bath stone Georgian terraces, Victorian houses in Taunton and Weston-super-Mare, and post-war estates.
Guide prices for bay window subsidence repairs in Yeovil
These are guide prices for Yeovil, using South West 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. | £620 – £1,850 | per bay |
| Traditional underpinning of a bay | £3,100 – £7,200 | per bay |
| Mini-piled bay underpinning | £5,150 – £12,400 | per bay |
Methods for bay window subsidence repairs
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
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
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.
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.
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.
Symptoms that point to bay window subsidence repairs
- Cracks above the bay window head or below the sill
- A vertical crack where the bay meets the front wall
- 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.
Frequently asked questions
How much will bay window subsidence repairs cost in Yeovil?
Guide prices for bay window subsidence repairs in Yeovil start from about £620 per bay, including VAT, on South West rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Yeovil?
Yes, Yeovil is covered, along with postcode districts BA20, BA21. We also cover nearby Dorchester and Bridgwater.
Is the ground in Somerset prone to subsidence?
Somerset mixes Lias clays, Mercia Mudstone, limestone hills and the peat and alluvium of the Levels around Bridgwater, which can settle. The former Somerset coalfield around Radstock and Midsomer Norton left recorded workings. Only an investigation can say why a particular building has moved.
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.
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 Yeovil
- Structural crack repairs
- Crack stitching
- Concrete repairs
- Subsidence insurance claim repairs
- Roof structure repairs
Bay window subsidence repairs near Yeovil
Not sure whether your Yeovil bay is still moving? Send dated photos, and we will suggest whether monitoring or a repair comes next.