How much does an architect cost in London? 2026 fees guide

What does Horizon Architecture charge?

Our published starting fees include planning drawings from £1,400 and a combined rear-extension planning and Building Regulations drawing package from £1,750. These are Horizon’s starting prices, not London-wide averages or a quotation for every property.

The combined extension and loft packages cover planning and Building Regulations drawings, subject to the agreed scope. Do not add standalone drawing fees to a combined package unless the quotation specifies extra work. VAT where applicable, statutory charges and third-party costs are additional. See our architectural fee table and exclusions.

Fixed fees, percentages and hourly rates

Architects may agree a fixed fee for defined deliverables, a percentage of construction cost, or time charges. A fixed drawing package can make an early stage easier to budget. A percentage appointment needs a clear definition of the construction cost used. Hourly work needs an agreed rate and a way to monitor time.

There is no single fee that describes every London home project. A planning-only appointment and a service continuing through tender and construction involve different responsibilities. RIBA explains the main fee structures.

What should your quotation include?

• Survey: whether a measured survey is included, commissioned separately or supplied by you.
• Design: the agreed options, meetings and number of revisions.
• Planning: drawings, supporting documents, submission and responses to council queries.
• Technical work: Building Regulations drawings, engineering coordination and any detailed specifications.
• Later stages: tender comparisons, construction information, site visits and contract administration, if required.

Ask for the exclusions, payment stages and charges for changed instructions in writing. Planning drawings alone are not a complete construction package.

Why fees vary between London homes

An occupied terrace with a tight side return needs different investigation from a straightforward detached extension. Existing alterations, uneven levels, conservation constraints and neighbouring windows can increase the work. Listed buildings, difficult access and uncertain drainage may require additional specialist advice.

A lower initial price is useful only when it includes the information your project needs. Compare the scope first, then the fee.

Keep design fees separate from the building budget

Allow separately for the builder, VAT, structural engineering, council application charges, Building Control, specialist reports and any Party Wall services. Confirm who pays each item and when. A construction contingency is also separate from the architect’s fee.

Use the London construction cost calculator for an initial building-cost range. It is not an architect-fee calculator or a contractor quotation. Check its assumptions and included allowances before adding other budget items.

Get a fee for your own property

Send the address, photographs, any existing plans and a short description of the work. Tell us whether you need help through planning, technical design or later construction stages. We can then define a scope rather than quote against an incomplete brief.

For an extension, read our rear-extension fees, timeline and process guide. If you are still choosing the consent route, start with permitted development in 2026.