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 St Albans?
In St Albans, a structural alteration typically costs £4,750–£10,000 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 East of England, where labour and materials are typically about 6% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical knock-through with steel beam | £4,750–£10,000 |
| Higher specification | £10,000–£12,500 |
What moves the price most:
- Span of the opening
- Floor and ceiling repairs
- Moving radiators, sockets and pipes
- Party wall involvement
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a structural alteration in St Albans?
Before anything is built in St Albans, we confirm which approvals apply 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.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
Handled as part of most structural alterations:
- Party wall notices where needed
- Steel beam supply and installation on padstones
- Making good, plastering and flooring repairs
- Fire protection to the steel
- Building control sign-off
- Temporary propping
How long does it take?
The build itself usually takes 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 St Albans
Many towns in the East of England have estates built since the 1970s, where garage conversions and rear extensions are popular.
From AL1 outwards, we take on projects throughout St Albans and the surrounding parts of Hertfordshire.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about structural alterations in St Albans
How long does a knock-through take?
Usually 1 to 2 weeks on site, plus a few days for plastering to dry.
Do you build structural alterations in St Albans?
Yes. We build structural alterations across St Albans, including postcodes AL1 and AL3. Every project starts with a free home visit.
Do I need a party wall notice?
In England and Wales, if the beam sits in a party wall, yes.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
How much does a structural alteration cost in St Albans?
In St Albans, a structural alteration typically costs £4,750–£10,000 for a typical knock-through with steel beam, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
