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 Letchworth Garden City?
In Letchworth Garden City, a structural alteration typically costs £4,750–£10,000 for a typical knock-through with steel beam, including VAT at 20% (standard rate). The guide for Letchworth Garden City reflects typical costs in the East of England, roughly 6% above the UK-wide figure. 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 |
Your quote will depend mainly on:
- Party wall involvement
- Moving radiators, sockets and pipes
- Span of the opening
- Floor and ceiling repairs
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 Letchworth Garden City?
Whether you need planning permission depends on your house and its location 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
What we take care of:
- Fire protection to the steel
- Building control application
- Party wall notices where needed
- Making good, plastering and flooring repairs
- Structural engineer’s calculations and drawings
- Temporary propping
How long does it take?
Expect 1 to 2 weeks on site for a typical knock-through. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Letchworth Garden City
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
Projects in Letchworth Garden City (SG6 and SG7) are surveyed in person before we quote, so the price reflects your actual property.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about structural alterations in Letchworth Garden City
How much does a structural alteration cost in Letchworth Garden City?
In Letchworth Garden City, 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.
Who approves a structural alteration in Letchworth Garden City?
Planning matters in Letchworth Garden City go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
Can the beam be hidden?
Often, by setting it within the ceiling depth. It depends on the joists and span.
Do I need a party wall notice?
In England and Wales, if the beam sits in a party wall, yes.
