The short answer
An architect designs changes to a building — extensions, conversions, new builds — and produces the drawings for planning and Building Regulations. A surveyor inspects and reports on an existing building: a building surveyor assesses condition and defects (the survey you get before buying), while other surveyors handle valuation, boundaries, party walls or measured surveys. They're different professions for different stages of a project. "Architect" is an ARB-protected title; chartered surveyors are typically members of RICS. You might use a surveyor to understand a property before you commit and an architect to design what you do with it — and on some projects you'll need both, plus a party wall surveyor if your work affects a shared wall.
"Architect" and "surveyor" are often lumped together as "the building professionals", but they do quite different things at different points. Here's a clear breakdown of who does what and when you'd use each.
Architect vs surveyor
- ArchitectDesigns changes
- Building surveyorInspects condition/defects
- Architect bodyARB / RIBA
- Surveyor bodyRICS
- Party wall surveyorShared-wall disputes
What an architect does
An architect's work is forward-looking and design-focused. They take a brief and turn it into a building or alteration:
- Design and layout for extensions, conversions and new builds — space, light, proportion and appearance.
- Planning drawings and the case for permission.
- Building Regulations drawings (often with a technologist or engineer).
- Frequently, running the project through the RIBA Plan of Work to completion.
"Architect" is a protected title — only ARB-registered professionals can use it, and most are RIBA chartered. What an architect doesn't typically do is produce a condition or defects report on an existing house you're thinking of buying — that's a surveyor's job.
What a surveyor does
"Surveyor" covers several roles, which is part of the confusion. The common ones for homeowners are:
- Building surveyor: inspects an existing property and reports on its condition and defects — the building survey or homebuyer report you commission before purchase. They advise on the state of the structure, damp, roof, and so on.
- Valuation surveyor: assesses what a property is worth, often for a mortgage lender.
- Party wall surveyor: a specialist who handles the formal process under the Party Wall Act when work affects a shared wall or boundary.
- Measured / land surveyor: produces accurate measured drawings of an existing building or site, which can feed a design.
Chartered surveyors are usually members of the Royal Institution of Chartered Surveyors (RICS). Their work is mostly about assessing what already exists, rather than designing what's new.
| Aspect | Architect | Surveyor |
|---|---|---|
| Main focus | Designing changes | Inspecting / reporting |
| Typical output | Drawings, design | Survey reports, valuations |
| Before buying a house | Not usually | Yes (building survey) |
| Professional body | ARB / RIBA | RICS |
| Party Wall Act work | No | Yes (party wall surveyor) |
Indicative comparison for guidance only. Sources: RICS and RIBA guidance.
When you need each (and when both)
Because they cover different stages, you may use them at different times — and a single project can involve both:
- Use a surveyor before you buy, to understand a property's condition and avoid expensive surprises; or for a valuation; or for a measured survey to base a design on.
- Use an architect once you own (or are committing to) the property and want to design an extension, conversion or new build.
- Use a party wall surveyor if your works affect a wall shared with a neighbour — a separate, specific role under the Party Wall Act, often needed alongside an architect-designed project.
The honest summary: an architect and a surveyor aren't really alternatives — they're specialists for different jobs. If your question is "is this property sound and what's wrong with it?", that's a surveyor. If it's "how do I design and build the changes I want?", that's an architect (or a technologist/designer). Many homeowners use a surveyor at purchase and an architect afterwards, and bring in a party wall surveyor if the works trigger that Act.
Frequently asked questions
Do I need a surveyor or an architect for an extension?
Mainly an architect (or designer/technologist) to design the extension and produce drawings. You might also need a measured survey of the existing house, and a party wall surveyor if the work affects a shared wall. A condition survey is usually for buying, not extending.
What's a party wall surveyor and do I need one?
A party wall surveyor handles the formal process under the Party Wall Act when your work affects a wall or boundary shared with a neighbour — common with loft steels, basements and boundary extensions. It's a separate role from your architect, often needed alongside one.
Is a surveyor cheaper than an architect?
It depends on the service — a homebuyer survey and an architect's full design service aren't comparable, as they do different things. They're not really substitutes: a surveyor reports on an existing property, while an architect designs changes to it.
Sources & further reading
- RICS — find a surveyor and survey types
- GOV.UK — Party Wall Act explained
- RIBA — working with an architect
Figures on this page are typical UK ranges drawn from published sources and depend on your specific project. They are guidance, not a quotation.