AH Architecture
Chartered Architecture · London & Nationwide

Frequently asked

Long answers to the six questions every client asks.

  1. 01

    How much will the architect fee cost?

    We work to fixed fees for residential projects. The figure depends on the project type, the planning route, and the construction value.

    For a typical loft conversion in West London the architect fee sits between 7 and 10 percent of the build cost. For a single-storey rear extension under permitted development, the fee is often lower. For a complex listed-building scheme it can be higher because the heritage statement, conservation consent, and constraints all add design time.

    Three productized engagement tiers cover most residential work: the £2,500 Feasibility Sprint, the £6,500 to £12,000 Planning Package, and the £18,000-plus Design and Tender. We quote in writing after the first conversation. The £2,500 paid on a feasibility credits against the next tier if you proceed.

  2. 02

    How long does planning take in West London?

    For householder applications, the statutory determination period is 8 weeks. For full planning it is 13 weeks. Major applications run to 16 weeks.

    Real-world timelines depend on whether your case officer requests amendments. A well-prepared application that aligns with the local plan typically lands within statutory timelines without amendments. An application that fights the local plan, or that triggers consultee responses from highways, conservation, or environmental health, often runs over.

    We design with the case officer in mind, which materially reduces round-trips. Our recent loft and extension work in Ealing, Hounslow, and Hillingdon has determined within the statutory window in most cases.

  3. 03

    What happens in the free initial consultation?

    Thirty minutes. No obligation.

    We will look at the property (in person if it is local, or via shared screen for further afield), review what you would like to do, and tell you honestly three things: whether the idea is buildable, what the planning likelihood looks like, and what the realistic build cost would be.

    You leave with a clear next step. That step is sometimes "engage us for a Feasibility Sprint." Sometimes it is "this is a permitted-development job, you can engage a builder directly and we are not the right firm." Sometimes it is "this needs a different specialist." We will tell you which.

  4. 04

    Do you provide structural calculations and engineering?

    Yes. We carry out civil and structural engineering for the projects we design, including steel-beam sizing, foundation design, and basement engineering.

    For projects with larger frames, deep basements, or unusual structural conditions, we coordinate with a named structural engineer with the relevant specialism. The cost of any external engineering input is itemised in the fee proposal so there are no surprises.

  5. 05

    Can I start work without planning permission?

    For some projects, yes, under permitted development. For most extensions, loft conversions, and any work to a listed building or in a conservation area, the answer is no.

    Permitted development rules cover certain rear extensions, certain loft conversions, certain side extensions, and certain ancillary buildings. The rules are tighter in conservation areas and Article 4 zones, both of which apply in parts of West London.

    The fastest way to find out which category your project falls into is the free initial consultation. We tell you on the first call whether you can proceed without an application, whether you should obtain a Lawful Development Certificate to protect yourself, or whether full planning is required.

  6. 06

    Do I even need a chartered architect for my project?

    If the project involves a planning application, a listed building, a conservation area, structural change, or any meaningful design decision, you benefit from a chartered architect.

    If the project is internal redecoration, a kitchen refit with no structural work, or a like-for-like replacement, you do not. In those cases a competent contractor or designer is enough, and we will tell you so.

    The advantage of a chartered architect with ARB registration is the regulatory standing: insurance backed up by professional indemnity, compliance with the ARB Code, adherence to RIBA professional standards, and the ability to act as contract administrator. For projects over roughly £50,000 in build cost, that standing usually pays for itself in avoided risk.