Structural engineering businesses assess how buildings and other structures carry and resist loads, and design solutions to make them safe, stable and fit for purpose. Their work may cover houses, commercial buildings, industrial sites, bridges and other infrastructure. Engineers consider factors such as materials, ground conditions, wind, use of the building and relevant design standards when preparing structural calculations and drawings. Customers may use structural engineers for new-build designs, extensions, loft conversions, alterations to load-bearing walls, basement works and repairs to damaged structures. Services can include surveys and inspections, advice on cracking or movement, assessments of existing structures, design of foundations and beams, and specifications for steel, concrete, timber or masonry elements.