Table of Contents
- Architect Cost in London – The Headline Numbers
- Fixed Fee vs Percentage: Which Is Better?
- What Affects Architect Cost in London Specifically
- Planning Complexity
- Project Density and Site Constraints
- Consultant Coordination
- Conservation Area Premium
- What Is, And Is Not, Included in an Architect’s Fee
- What Is Typically Included
- What Is Typically Not Included
- When Is the Fee Worth It?
- Talk to Discover Architecture
Architect cost in London is one of the most-searched questions at the start of any residential or commercial project, and also one of the least helpfully answered.
Most online guides give you a percentage range and a national average. Neither tells you what you will actually pay in London in 2026, how fees are structured across different stages nor what changes if you are working in a conservation area, a sensitive borough or a listed building.
This guide covers all of it.
Architect Cost in London – The Headline Numbers
The most common way for a London architect to charge for full services, from initial design through to construction oversight, is as a percentage of the total build cost. In London, that percentage typically sits between 8% and 15% for residential projects, with smaller or more complex projects sitting at the higher end of the range and larger, more straightforward schemes sitting lower.
What does that look like in practice?
| Project type | Typical build cost | Typical architect fee |
| Single-storey rear extension | £80,000 – £120,000 | £8,000 – £15,000 |
| Double-storey extension | £120,000 – £200,000 | £12,000 – £24,000 |
| Loft conversion | £60,000 – £100,000 | £6,000 – £12,000 |
| Full house refurbishment | £150,000 – £400,000 | £15,000 – £45,000 |
| New build residential | £300,000 – £700,000+ | £25,000 – £70,000+ |
These are ranges, not fixed prices. The actual fee for your project will depend on several factors covered below. Here at Discover Architecture, we offer fixed fees for each service we provide, so our clients can choose what services suit them best.
Fixed Fee vs Percentage: Which Is Better?
Many London architects, particularly for residential extensions and defined-scope projects, offer a fixed fee rather than a percentage. This gives you cost certainty from the outset and removes any structural incentive for the architect to expand the scope of the project.
Fixed fees for planning-only services on a straightforward London extension typically start at around £2,500 to £5,000. Full services from concept through to building regulations and technical drawings can range from £8,000 to £25,000+ depending on the size and complexity of the project.
For larger or more complex schemes, percentage fees are more common. They account for the fact that design time scales with project complexity in ways that can be difficult to predict at the outset.
Hourly rates exist but are relatively uncommon as a primary fee structure for residential projects. When they do apply, usually for consultation, feasibility studies or additional design iterations outside an agreed scope, London architects typically charge between £150 and £250 per hour.
What Affects Architect Cost in London Specifically
London architect fees are consistently higher than the national average for several reasons.
Planning complexity
London’s boroughs each operate their own planning culture, and in boroughs like Richmond upon Thames – which covers Twickenham, Kew and Ham – the planning environment is among the most demanding in the country. Working in a conservation area, with a listed building, or in a borough with active Article 4 directions requires more design development time, more pre-application engagement and a more carefully constructed application narrative. That additional work is reflected in fees.
Project density and site constraints
London plots are typically smaller, more constrained and more likely to involve party wall considerations, overlooking issues or proximity to neighbouring structures. These constraints increase design complexity and, with it, the time required to resolve them properly.
Consultant coordination
Most London projects require additional consultants alongside the architect: a structural engineer, a party wall surveyor and sometimes a planning consultant or heritage consultant. The architect coordinates these consultants as part of the service. Their fees sit separately from the architect’s fee and should be budgeted for in addition.
Conservation area premium
Applications in conservation areas require a more considered design approach, a design and access statement and, often, pre-application advice from the local authority. This adds both professional time and council fees. In Richmond, where 85 conservation areas cover a significant proportion of the borough’s housing stock, this uplift applies to a very large number of projects.
What Is, And Is Not, Included in an Architect’s Fee
This is where confusion is most common. Always ask for a written breakdown before agreeing a fee.
What is typically included:
- Initial feasibility project appraisal
- Concept design and design development
- Planning drawings and application documents (including design and access statement)
- Liaison with planning officers during the application process
- Technical and building regulation drawings
- Tender documentation for contractor selection
- Site visits and on-site construction oversight (where full services are agreed)
What is typically not included, and sits outside the architect’s fee:
- Structural engineer fees
- Party wall surveyor fees
- Planning application fees (paid direct to the council — currently £528 for a householder application in England as of 2025)
- Building control fees
- Pre-application advice fees charged by the local authority
A typical London extension project with a build cost of £100,000 might involve:
- Architect fee: £10,000 – £14,000
- Structural engineer: £1,000 – £2,000
- Party wall surveyor: £800 – £1,500
- Planning application fee: £528
- Building control: £1,000 – £1,500
Total professional and statutory costs: approximately £13,000 – £20,000 on top of the build cost.
When Is the Fee Worth It?
In London, a well-designed and correctly submitted planning application from an experienced architect regularly unlocks value that comfortably exceeds the professional fee. This is particularly true for:
- Projects in conservation areas, where design quality is assessed as part of the planning decision
- Properties with development potential that an experienced architect can identify and maximise
- Projects where a previous application has been refused and the design case needs to be made more persuasively
- Developer clients for whom the speed of planning approval directly affects the viability of the project
Saving money by using a cheaper, less experienced designer on a planning-sensitive London project is a common decision that often costs significantly more in the long run through refusals, redesigns and abortive fees.
Talk to Discover Architecture
At Discover Architecture, we work across London on residential, commercial and developer projects. We are transparent about our fees from the first conversation, and we will tell you clearly what your project needs and what it will cost before you commit to anything.
Get in touch to discuss your project and get a fee indication