Flat Conversion Pricing
FLAT CONVERSION PRICES
We prepare detailed Planning Applications, Building Regulation Drawings and Structural Calculations to achieve consent for your single-storey extension project with our extensive knowledge and experience. Please see our single-storey extension prices.
Site Survey
From £350
£0
- We provide a full measured site survey with photography
- Free site survey worth of £350 ( Discount end date 21.10.2025)
Planning Application Drawings
From £1,500
- Existing Floor Plans, Elevations and Sections to 1:50 or 1:100 scale @ A3
- Proposed Floor Plans, Elevations and Sections to 1:50 or 1:100 scale @ A3
- Prepare Ordnance Survey map, block plan and site plan
- Providing a design options to the client with full expert support and advice Electronic submission of the planning application, fill in application forms and CIL
- questions.via the Planning Portal ( Planning application Fee to the council not included)
- Management of the planning application including liaison with the Local Planning Authority until your application has been decided
Structure Calculations
From £1,250
- Structural elements drawings (walls, beams, columns, foundation,roof etc.), including their size and design
- Structural elements drawings (walls, beams, columns, foundation,roof etc.), including their size and design
- Providing a design options to the client with full expert support and advice
Building Regulation Drawings
From £1,800
- Building Regulation Drawings with the details
- Structural calculation report
- We will complete building control application forms and act as your agent to your local council or private building control inspectorate
- Providing a design options to the client with full expert support and advice
Studio20 architects
Frequently Asked Questions – Flat Conversion Pricing & Costs
What are typical flat conversion costs?
Flat conversion costs vary depending on property size, existing layout, structural works, fire safety provisions, access upgrades, and finishes. Key contributors include design fees, planning and building regulation submissions, structural alterations, internal fit-out, and any new services (electrics, plumbing, heating) required.
Why are flat conversion costsin London often higher?
Flat conversion costs in London are generally higher than in other regions due to labour rates, material costs, and tighter planning/building control requirements in many boroughs. Site constraints such as restricted access or shared building structures can also increase cost.
How do the house-to-flat conversion costs compare to other conversions?
House to flat conversion costs typically include subdivision of existing space, creation of separate entrances, additional kitchens/bathrooms, fire separation, sound insulation, and compliance with multiple occupancy standards. These added requirements mean house-to-flat conversion costs can be higher than single-family internal alterations.
What influences the flat conversion costs the most?
The biggest influences on flat conversion costs are structural changes (e.g., adding or removing load-bearing walls), compliance with Building Regulations (especially fire safety and means of escape), access and lift requirements, and the specification of internal finishes. Efficient architectural design helps manage these costs.
Can I get an estimate of flat conversion costs in London before detailed design?
Yes, many practices provide a rough budget estimate for flat conversion costs London based on brief project details (approximate size, number of units, level of finish). However, a reliable estimate usually requires a measured survey and concept design from an architect.
How do architectural fees influence the overall flat conversion costs?
Architectural fees cover concept design, planning support, technical drawings, and coordination with engineers and specialists. While this adds to upfront cost, good architectural involvement often reduces overall flat conversion costs by avoiding build errors, minimising revisions, and streamlining permissions.