Structural Calculations Online,
Delivered Across the UK.

Yes — if you are building an extension, you are adding load. A new extension sits on the ground, contains heavy construction materials and needs a sound foundation. Without proper calculations, poorly supported structures develop settlement cracks, separation and long-term structural problems. Everything you build — floor, walls and roof — transfers load down to the foundations, and that load needs to be calculated correctly before work begins.

Extension means load, and load means calculations — full stop. If your project has a roof, walls and a floor sitting on the ground, structural calculations are required. There is no size threshold below which you can skip them. Homeowners who try to cut this corner often end up spending significantly more fixing problems further down the line.

For a typical house extension we calculate: the roof joists and beams carrying the roof load; load-bearing wall assessments; lintel sizing for any door or window openings; the steel beam required where the original house wall is opened up to connect the extension to the existing space; column and pad foundation design where required. Every element that carries load needs to be checked.

In most cases, yes. If your architect or designer has produced clear existing and proposed drawings — with dimensions, scale bars and clean PDF files (DWG files speed things up further) — we can carry out the full structural calculations remotely without visiting site. Where anything is unclear, our team will contact you or the builder directly to clarify before producing the report. Site visits are arranged where genuinely needed.

Our extension structural calculations start from £700 for a single-storey rear extension. The final price depends on the complexity of the project — additional storeys, multiple steel beams, complex roof structures or large openings will increase the fee. We provide a fixed-price quote within 24 hours of reviewing your drawings, with no hidden costs.

For a standard extension with clear architectural drawings, we typically deliver within 2–3 working days. If the drawings require clarification or there are several rounds of communication needed, it can take up to one week. Express delivery is available at an additional fee for urgent projects.

Yes. All our structural calculation reports are stamped and signed by a UK-qualified structural engineer and are accepted by Building Control across England and Wales. We have 17 years of experience working on UK projects and our reports meet current British Standards and Eurocodes.