Architect fee calculator
What should an architect cost for your extension, loft or renovation? Choose your rough build budget and how much of the job you want them to run, and see the typical fee range.
Architect fee calculator
Typical fee: design to planning permission
£2,250 - £3,750
Indicative range for guidance, not a quote. Fees vary with practice, project complexity and how much structural engineering input is needed - ask each architect exactly which work stages their fee includes.
How this estimate works
Architect fees follow the scope more than anything else. A fixed-fee package for measured survey and planning drawings suits simple, well-defined projects. Fuller involvement is normally priced as a percentage of build cost: typically 3% to 5% to take a design through planning, and 8% to 12% for full service from first sketches to site visits during the build.
The percentages fall as budgets rise - designing a £300,000 project isn't four times the work of a £75,000 one - which the calculator reflects by working from your budget band.
Fees are only comparable when scopes are: two quotes £2,000 apart often differ in whether building regulations drawings, structural engineer coordination or site-stage involvement are included. Always compare against the work stages listed, not the bottom line alone.
What affects architect fees
- Scope - drawings only, through planning, or full service to completion
- Project complexity: structural gymnastics, awkward sites and listed buildings take more design time
- Whether building regulations packages and structural coordination are included or priced separately
- Planning difficulty - conservation areas and non-standard designs mean more iterations
- The practice itself: sole practitioners typically charge less than established studios
Frequently asked questions
Do I need a full architect, or will a technologist do?
For most domestic extensions, an architectural technologist or experienced designer can produce excellent drawings at lower fees. Architects (an ARB-protected title) earn their premium on design-led projects, tricky sites and planning battles. Credentials appear on every Homeply profile, so you can choose deliberately.
What are the RIBA work stages people mention?
A standard map of a project from brief to completion, used to define what an architect's fee covers. You don't need to know the numbering - just ask any quote to say which stages it includes, and compare like for like.
Is a percentage fee a conflict of interest?
It can feel that way - a bigger build cost means a bigger fee. In practice reputable practices agree the budget early and design to it, and you can ask to convert the percentage to a fixed fee once the scope is settled, which many practices accept.
When in my project should I engage an architect?
Before you're committed to anything structural - ideally at the 'we think we want to extend' stage. Early design advice is cheap compared with redesigning around a decision that shouldn't have been made, and it strengthens your planning application.
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