Is my extension structurally straightforward?
An extension changes how the existing house is loaded: new foundations next to old ones, an opened-up rear wall, and a roof tying into existing structure. Our assessment sets out what your project involves before you commission drawings.
What the assessment covers
- • Extension type: single storey, two storey, wrap-around, side return
- • Connection to the existing structure and the opening formed in the rear wall
- • Likely foundation issues: existing depth, trees, made ground, drainage runs
- • Roof form and how new loads reach the ground
What you send us
- • Photos of the existing rear and side elevations and the garden level
- • Existing plans and any sketch of the proposed extension
- • Approximate footprint dimensions and number of storeys
- • Property age, soil type if known, nearby trees and neighbouring boundaries
What you receive
- • Indicative risk level and confidence rating
- • Budget range for the structural elements
- • Watch points: foundations, party walls, drainage diversion, thermal bridging
- • Which consultants and approvals your project is likely to need
Avertissement légal
Ce document est informatif. Il ne constitue ni une note de calcul, ni un diagnostic réglementaire, ni une validation d'exécution de travaux. Aucun avis produit par la plateforme ne constitue une note de calcul, un diagnostic réglementaire ou une validation d'exécution de travaux. Aucune décision de travaux ne doit être prise sans validation par un professionnel qualifié (architecte, bureau d'études structure, ingénieur).
Frequently asked questions
Is my extension permitted development?
Many single storey rear extensions fall under permitted development for houses, subject to size limits, but flats, conservation areas and listed buildings do not. Always confirm with your local planning authority.
Do I need a party wall agreement?
If you build on or near the boundary, or excavate within three metres of a neighbouring structure, the Party Wall etc. Act 1996 usually applies in England and Wales. Serve notice early — it takes weeks, not days.