Architect Fees in London: How They Work

The short answer

Architect fees for a London house extension are charged in one of three ways: a fixed fee for a defined stage (such as a planning drawing package), a percentage of construction cost for a full-service appointment, or an hourly rate for early feasibility and advice. Appointing stage by stage keeps cost proportionate to progress.

Fixed-price drawing and planning packages are the most predictable starting point. Our own fixed fees for the common routes are shown below, and the separate council fees are set by government — or work through both for your project with our cost estimator.

Why fees vary

There is no single price for architectural services because projects differ enormously in scope, complexity and risk. A set of planning drawings for a modest rear extension is a very different undertaking from a full-service appointment on a whole-house refurbishment with a basement, planning, listed building consent and contract administration. Fees reflect the work involved, the consultants required, and how far through the project you want support.

Common fee structures

Architectural fees are usually structured in one of three ways, sometimes in combination. A fixed fee or lump sum is common for well-defined stages such as a planning drawing package. A percentage of construction cost is often used for full-service appointments, where the scope grows with the project. Time-based or hourly fees suit early feasibility, advice and open-ended work where the scope is not yet clear.

Project stages

It helps to think of a project as a series of stages: feasibility, concept design, planning, technical and building regulations design, tender, and construction support. Many clients appoint stage by stage, which keeps cost and commitment proportionate to progress and lets you pause to make decisions between stages.

• Feasibility — testing what is achievable
• Concept design — developing the design
• Planning — drawings and submission
• Technical / building regulations — construction information
• Tender — obtaining and comparing builder prices
• Construction support — answering queries and, optionally, contract administration

Planning-only packages

A planning-only package covers feasibility and the drawings and documents needed to make a planning application. It is a defined scope, often quoted as a fixed fee, and is a sensible way to test whether a project can be approved before investing in full technical design. It does not, however, give you the drawings needed to build.

Building-regulation packages

A building-regulations package adds the technical drawings and coordination needed to satisfy building control and to build, usually including structural engineer coordination. It typically follows planning approval (or runs alongside it for permitted-development projects) and is what a contractor prices and builds from.

Full-service appointments

A full-service appointment runs from early feasibility through to completion, including design, approvals, technical design, tender and construction-stage support such as contract administration. It offers the most continuity and oversight and is common on larger or higher-value projects where coordination matters most.

Additional consultant costs

Architectural fees usually do not include other consultants a project needs, such as a structural engineer, party wall surveyor, measured survey, heritage consultant or approved inspector/building control fees. These are appointed and paid separately, and we will flag the ones a project is likely to require so you can budget for them.

How to compare quotes

Cheaper is not always better value if it buys a narrower scope. When comparing quotes, check what stages each fee covers, whether building regulations and structural coordination are included, what is excluded, and how additional work or revisions are charged. A clear scope makes quotes comparable; a vague one usually hides gaps that surface later.