A structural engineer works out how a building carries its weight and designs the beams, foundations and supports needed when that changes. If your project touches the structure, building control will normally want their calculations before approving the work.
When you usually need one
- Removing or opening up a load-bearing wall, or making a new opening in one.
- Fitting steel beams, for example across a side-return or rear extension opening.
- A loft conversion, because the existing ceiling joists were not built to carry a floor.
- Extending, where new foundations or an altered roof structure are involved.
- Working on a building with signs of movement such as cracks, or on an unusual structure.
What an engineer produces
- Calculations that show the beams, foundations or supports are adequate.
- Drawings with the sizes and positions of the steelwork or structure.
- Details for building control, and sometimes a site visit to check the work as it goes.
Architect, engineer and builder: who does what
An architect or designer deals with layout, appearance and planning drawings. The engineer deals with the structure. The builder carries out the work to the drawings and calculations. Ask for the engineer’s design before steel is ordered, because the beam sizes affect cost and the build order.
See how this fits the wider picture in removing a wall: structural alterations, Building Regulations for a loft conversion and what affects the cost of an extension.
This guide is general information for homes in England and is not legal or planning advice. Rules can change and differ between properties and local authorities, so always confirm the position with your council or a qualified professional.
Request a quote and tell us what you would like to change; we will say what structural input is likely to be needed.