What is a structural alteration?
A structural alteration changes how a house carries its loads, most often by removing a load-bearing wall and replacing it with a steel beam. It is how kitchens and dining rooms become open-plan, and how extensions are joined to the original house.
How much does a structural alteration cost in Southsea?
In Southsea, a structural alteration typically costs £5,000–£10,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate). We start from a UK-wide guide and adjust it for the South East, where labour and materials are typically about 12% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical knock-through with steel beam | £5,000–£10,500 |
| Higher specification | £10,500–£13,000 |
What moves the price most:
- What sits above the wall
- Party wall involvement
- Span of the opening
- Flush or downstand beam
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a structural alteration in Southsea?
Here is how the rules work for a structural alteration in England. In England removing a load-bearing wall does not need planning permission but does need building regulations approval with an engineer’s calculations. If the beam bears on a party wall, a party wall notice must be served.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
Handled as part of most structural alterations:
- Making good, plastering and flooring repairs
- Steel beam supply and installation on padstones
- Building control application
- Temporary propping
- Fire protection to the steel
- Building control sign-off
How long does it take?
Build time is typically 1 to 2 weeks on site for a typical knock-through. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.
Building in Southsea
The South East has a broad mix of housing, from Victorian terraces in the towns to post-war semis and newer estates, so extension types vary street by street.
Our Southsea coverage includes postcode districts PO4, and we also work in nearby places such as Portsmouth, Gosport and Ryde.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about structural alterations in Southsea
How long does a knock-through take?
Usually 1 to 2 weeks on site, plus a few days for plastering to dry.
How do I know if a wall is load-bearing?
Only a survey can confirm it. Walls that carry floor joists, roof loads or walls above are load-bearing. We check on site and the engineer confirms.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
Do you build structural alterations in Southsea?
Yes. We build structural alterations across Southsea, including postcodes PO4. Every project starts with a free home visit.
How much does a structural alteration cost in Southsea?
In Southsea, a structural alteration typically costs £5,000–£10,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.