Building Foundations
Foundations spread the building's load into the ground. For UK houses and extensions, the engineer will choose from:
- Strip foundations — continuous concrete strips under walls
- Trench-fill — deeper concrete-filled trenches, common on clay
- Raft — a slab under the whole footprint where ground is weak
- Piled — where good ground is deep or trees and drains complicate matters
Depth is influenced by soil type, nearby trees, drains and the existing foundations.
Structural Framing
Structural framing is the system that carries loads from roof and floors to the foundations:
| Frame type | Typical use |
|---|---|
| Masonry (loadbearing walls) | Most existing UK houses |
| Timber joists and rafters | Floors and roofs |
| Steel beams and columns | Openings, extensions, lofts |
| Concrete | Foundations, slabs, basements |
What a Structural Plan Shows
- Foundation layout, size and depth
- Steel beam and column positions and sizes
- Floor joist spans and direction
- Roof framing
- Padstones, bearings and connections
- Notes for Building Control and the builder
See our structural drawings and calculations service.
Sustainable Structural Improvements
Good structural design can lower embodied carbon:
- Keep and reuse existing walls and foundations where safe
- Avoid over-sizing steel through accurate calculations
- Use timber framing where appropriate
- Reduce concrete volumes through efficient foundation design
Next Steps
- Extensions →
- Loft Conversions →
- House extension structural guide →
- Planning permission and Building Control →
📞 Call 07401 650600 or email us — covering Ilford, Redbridge, Newham, East London, Tilbury, Grays and Thurrock.
