ARB registered · RIBA Chartered Practice Call 07720 813035
Call now
Residential architecture service

House Extension Architect

A successful extension should improve more than floor area. We design around daylight, circulation, privacy, garden connection, planning policy and the long-term value of the home.

House Extension Architect example by Hepburn Architects
Suitable for

Projects we can support.

  • Single-storey rear extensions
  • Two-storey side and rear extensions
  • Wrap-around extensions
  • Kitchen and family-room extensions
  • Period-property additions
Our process

A structured route through the project.

01

Feasibility and survey

We review the property, brief, planning history, neighbouring relationships and likely approval route.

02

Design development

Options are tested against space, light, external appearance, buildability and budget priorities.

03

Planning submission

We prepare the drawings and supporting information needed for permitted development, lawful development or full planning.

04

Technical design

Where appointed, the approved concept is developed into a coordinated Building Regulations package.

Relevant project experience

Architecture demonstrated through real work.

A selection of extension and whole-home transformation projects showing how planning, space and material decisions are developed together.

Typical deliverables

What the appointment may include.

The final scope is confirmed in a written fee proposal tailored to the property and approval route.

Existing and proposed plans
Elevations and sections
Planning strategy advice
Design and Access Statement where required
Building Regulations drawings
Consultant coordination
RIBA-aligned scope

Clear stages and responsibilities.

The appointment is aligned to the RIBA Plan of Work stages that are proportionate to a residential project.

Stage 0–1: project appraisal and brief
Stage 2: concept design and options
Stage 3: planning and spatial coordination
Stage 4: Building Regulations and technical design
Typical programme

Indicative timescales.

  • Survey and appraisal: usually 1–2 weeks
  • Concept and planning design: usually 3–5 weeks
  • Planning decision: commonly 8 weeks after validation, but delays occur
  • Technical design: commonly 3–5 weeks after the design is fixed
Fees

Proportionate fixed scopes.

Most extension appointments are offered as a fixed fee after the property, brief, planning route and required stages have been reviewed. The online calculator provides an early guide only.

Use the fee calculator
Usually excluded

Separate appointments and costs.

  • Structural engineer calculations
  • Planning and Building Control fees
  • Party Wall surveying
  • Specialist ecology, tree, drainage or flood reports
  • Contract administration or site project management unless separately agreed
Independent client feedback

Clear advice and dependable communication.

Great service! David was on time with the plans, and his advice has been invaluable throughout the process.
Avtar, BirminghamView on MyBuilder
David was a pleasure to deal with throughout. He was easy to talk to and nothing was too much.
Verified homeownerView on Checkatrade
Frequently asked questions

Common questions about this service.

Do all extensions need planning permission?

No. Some extensions may fall within permitted development, but the limits depend on property type, previous alterations, location and design.

Can you help after a refusal?

Yes. We can review the decision notice and officer report, then advise whether redesign, resubmission or appeal is the strongest route.

Do you provide construction drawings?

Yes. Our Building Regulations packages can include plans, sections, specifications and coordinated technical details.

Will you manage the builder on site?

Our core service focuses on design, planning and technical information. Any construction-stage support must be defined and agreed separately.

Discuss your project

Speak directly with a residential architect.

Call now or book a free 30-minute consultation to discuss the property, approval route and likely next steps.