What is the difference between an architect, a surveyor and a structural engineer?
Different professions with different training, different legal protections and different jobs — and engaging the wrong one wastes money and time.
Architect. Designs buildings and spaces, prepares drawings for planning and construction, and may administer the building contract.
"Architect" is a legally protected title in the UK — only those registered with the Architects Registration Board may use it. "Architectural designer" and "architectural technologist" are not protected, and describe people who may be highly competent and are not architects.
When you need one: significant design work, complex or constrained sites, planning applications likely to be contentious, listed buildings, and where the design itself is the point.
Surveyor. A broad profession, and the specialism matters enormously:
Building surveyor — condition, defects, specification and project management. This is who conducts a building survey on a property purchase and who diagnoses damp, movement and building failures.
Valuation surveyor — what a property is worth, which is a different job from assessing its condition.
Quantity surveyor — costs, tendering and contract administration.
Party wall surveyor — a specific statutory role under party wall legislation.
Structural engineer. Calculates loads and structural adequacy — whether a beam will carry what is placed on it, what size it must be, and how loads transfer to the ground.
When you need one specifically: removing or altering a load-bearing wall; forming a large opening; loft conversions; underpinning; investigating cracking and movement; and anything building control will require calculations for. An architect designs the space; the engineer confirms it will stand up, and building control will generally require the engineer's calculations.
How to check credentials: ARB registration and RIBA membership for architects; RICS membership for surveyors, with the specialism confirmed; and IStructE or ICE membership for engineers.
Who to engage first. For a straightforward extension, an architect or architectural designer leads and engages the engineer. For a defect or a movement problem, a building surveyor diagnoses first — engaging a builder to fix something nobody has diagnosed is the most common and expensive error.
Professional indemnity insurance is the practical reason to use qualified professionals, since it means advice carries recourse.