A structural engineer is required to give structural calculations and drawings for numerous reasons. Among these include, but are not limited to, building regulation approval in the UK.
A structural engineer is often required when planning permission is needed for a new build or an extension. They will assess the project and calculate the loads that the proposed structure will be subject to. They will also produce drawings which show how the proposed structure will be supported.
In some cases, a structural engineer may also be required to provide a report which outlines any potential problems with the proposed structure. This report can then be used to make any necessary changes before construction begins.