Single Storey Extension Pricing
Through a unique combination of engineering, construction and design disciplines and expertise.
SINGLE STOREY REAR & SIDE EXTENSION PRICES
Free site survey worth of £350 don't miss the opportunity.
Single storey extension pricing varies across London find out how architects plan, price, and deliver cost-effective solutions. 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.
SINGLE STOREY REAR & SIDE EXTENSION PRICES
Free site survey worth of £350 don't miss the opportunity.
Single storey extension pricing varies across London find out how architects plan, price, and deliver cost-effective solutions. 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)
- We provide a full measured site survey with photography
- Free site survey worth of £350 ( Discount end date 21.10.2025)
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)
Structure Calculations
From £950
- Structural elements drawings (walls, beams, columns, foundation,roof etc.), including their size and design
- Structural calculation report
- Providing a design options to the client with full expert support and advice
Planning Application Drawings
From £800
- 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)
- 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
Building Regulation Drawings
From £950
- 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
Planning Application Drawings
From £800
- 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
- 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 £950
- Structural elements drawings (walls, beams, columns, foundation,roof etc.), including their size and design
- Structural calculation report
- Providing a design options to the client with full expert support and advice
- Structural elements drawings (walls, beams, columns, foundation,roof etc.), including their size and design
- Structural calculation report
- Providing a design options to the client with full expert support and advice
Building Regulation Drawings
From £950
- 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
- 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
Here’s what our clients have to say.
This was my first project and I was nervous at the beginning as every thing was new to us. Nadir was very helpful in guiding us through the entire project from planning stages to choosing materials to assigning builders; giving us assurances that the project would be finished on time and on budget. He also provided us with ideas for interior design. The build was of high quality with great care taken throughout. Geroge and his team were excellent builders and really gave us a peace of mind. There were issues with some of the materials (not their faults but due to Covid restrictions and the subcontractors), all of which were sorted out by Nadir and George between themselves. I’m hugely impressed by the after build care (nagging jobs and other issues). They were all addressed without fuzz.
A true test of a beautiful house is whether you are proud of showing it to guests. I’d say this project has passed this test with the highest score. We are still in love with the extension 3 years after it has finished. We’ve also received a lot of compliments from our guests.
I highly recommend both Nadir and George for their service.
Frequently Asked Questions – Single Storey Extension Costs & Pricing
What are typical single storey extension costs?
The single storey extension costs vary depending on size, design complexity, materials, site conditions, and finishes. In general, prices are influenced by construction scope, structural requirements, foundations, drainage, and landscaping. A reputable architect will provide a detailed breakdow,n so you understand where the money is allocated.
What is the average cost of an extension in the UK?
The average cost of an extension in the UK can vary widely based on region and specification, but many residential extensions fall into a broad range per square metre. Factors include existing structure, planning conditions, quality of finishes, and whether specialist structural work is needed.
How do architects help with the cost of single storey extension planning?
Architects help control the cost of single storey extension by developing efficient layouts, advising on materials and phasing, and coordinating tendering, so you receive competitive construction quotations. Good architectural design can reduce build risk and prevent costly changes later.
What influences the Single Storey Extension Price?
The Single Storey Extension Price is influenced by: overall footprint, roof design, structural works (e.g., support beams), site access, drainage, and local planning requirements. Higher specification finishes, complex geometry, and heritage/party-wall requirements can also increase costs.
What should I budget for single storey extension cost in my project?
While every project is different, homeowners often budget with a range per square metre based on typical build costs in their area. A preliminary architectural feasibility will give you a clearer picture of likely single storey extension cost specific to your property and design brief.
Why is it important to understand single storey extension price early?
Understanding single storey extension price early helps you set realistic expectations, make informed design decisions, and avoid scope changes mid-build. Early cost advice allows architects to shape the design around your budget rather than trying to retrofit cost savings later.
Can I get a quote for the average cost of single storey extension before design starts?
Yes, many practices, including architectural firms, can provide an average cost of single storey extension estimate based on your brief, size preferences, and site conditions. This helps you decide whether to proceed to detailed design and planning.
What role does design and planning have on single storey extension costs?
Good design can reduce single storey extension costs by optimising structure, avoiding unnecessary complexity, and ensuring compliance with local planning rules. An architect can also help minimise unexpected costs by factoring in drainage, insulation, and Building Regulations from the start.