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Double Storey Extension Pricing

Through a unique combination of engineering, construction and design disciplines and expertise.

Double Storey Extension Pricing

Through a unique combination of engineering, construction and design disciplines and expertise.

DOUBLE STOREY REAR & SIDE EXTENSION PRICES

Double storey extension pricing broken down with expert London architects and real design options tailored to different needs and budgets. We prepare detailed Planning Applications,

Building Regulation Drawings and Structural Calculations to achieve consent for your double storey extension project with our extensive knowledge and experience. Please see our double storey extension prices.

Architects Near Me

DOUBLE STOREY REAR & SIDE EXTENSION PRICES

Double storey extension pricing broken down with expert London architects and real design options tailored to different needs and budgets. We prepare detailed Planning Applications, Building Regulation Drawings and Structural Calculations to achieve consent for your double storey extension project with our extensive knowledge and experience. Please see our double storey extension prices.

Spatial Planning and Layout
Site Survey
From £350
£0
Planning Application Drawings
Planning Application Drawings
From £1,100
Restrospective Planning
Structure Calculations
From £1,300
Building Regulation Drawings for Building Control
Building Regulation Drawings
From £1,300

Studio20 architects

YEARS IN BUSINESS
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PROJECTS COMPLETED
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Here’s what our clients have to say.

Studio20 Architects place picture
4.8
Based on 31 reviews
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Bill profile pictureBill
20:34 16 Nov 25
Hi Nadir and Georghe. We would all like to thank you both. Nadir, for project managing the task so efficiently. We really appreciated your guidance and friendly advice. Georghe, we would like to thank you for your hard work and expertise and especially to thank you and your workers for enabling Andrew to live onsite throughout the build. The house has been transformed. It was a pleasure to work with you all. Paula Bill and Andrew. 🙏
Morespace Design Info profile pictureMorespace Design Info
12:21 09 Sep 25
Swapnil Dhoke profile pictureSwapnil Dhoke
19:25 21 Jul 25
Nadir created Building drawings for our single storey rear and side extension. Drawings have all required details with clear and detailed specifications for structure, foundations, insulation, and drainage that even I can understand. Some of the builders who gave us quote for the build were very impressed with the drawings that they ask for his contact details. I would highly recommend Nadir for his work on building drawings.
Mayuri Parmar Amin profile pictureMayuri Parmar Amin
14:00 06 Jul 25
We used Studio20 architects to support both planning and building control for our existing house renovation and a new build. They were professional, reliable, friendly and strategic and helped us overcome a planning issue that we were facing with Sutton council. Nadir is really knowledgeable and can provide services to support into the build stage of a project- I would highly recommend them!
Selena S profile pictureSelena S
15:10 18 Jun 25
Nadir has been helping us with the BR designs. Lovely person and clear communication. We are at early stages of building work. We have recommended him already and would be working with him in the future too.
Gavinder Pawar profile pictureGavinder Pawar
10:21 18 Mar 25
Nadir has done a fantastic work for us-on first visit he gave us clear advice, was proactive with ideas and really helped us after a previous planning failure. He was confident in the right approach to take in both design and planning. We were also impressed at how prompt he was to communicate and complete each stage of the design. Highly recommended!
Duc Trung Phan profile pictureDuc Trung Phan
13:40 04 Dec 24
We renovated our house in 2021. The project was a wrap-around, L-shaped, kitchen & back extension. Studio20 (Nadir) was the architect & project manager while George was the builder. The project lasted 7 months from April to December 2021. I write this review now (December 2024) 3 years after completion as you can only truly assess the quality after the build a few years.

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.

Popular Questions, you may be interested in

If you are looking to newly build,change the use of your land or building, or for a house extension this means you will need planning permission. A Planning Application includes details of your proposal which is then sent to the Local Planning Authority. LPAs will need to check you application and grant it so that you may start works. Quite simply, it is a way that your local council can check that the proposed development is designed with sensitivity to local guidelines and is suited to the relevant site, street, and area. If we did not have this system in place, we could find buildings that have no uniformity in their designs, form or function. This way, the United Kingdom which is rich in heritage can keep your home as part of it’s identity whilst allowing you to make exciting and necessary changes.

Local Planning Authorities are generally the local council borough and these LPAs will have guidelines and links to explain what are within your rights to make changes to your property. They are usually receptive to pre-applications, but since three years ago, most of the London Boroughs have adopted a fee for their pre-application advise. A good thing to know, no matter if you are doing a small single storey rear extension, a loft converson or a large new build – most LPAs take approximately 6 to 8 weeks to make a decision on your project.

Single-Storey Rear Extensions: The good news is, if you live in a terrced or semi-detached house in 2020, Local Planning Authorities have relaxed the rules and allow for extensions to go to 6 meters . If you live in a detahced house, single storey rear extensions can be up to 8 meters in depth. Just be aware that if your property type is a flat, maisonette or in a conservation area, then you will need full planning permission.

Side Extensions: Side extensions fall under permitted developent if they do not extend more than half the width of the original house. You can extend a maximum of 3 meters as long as it is a single storey extension and does not extend pas the front elevation.

Double-Storey Extension: As of October 2019, new rules are being phased in which will allow homeowners to build extensions onto detached homes without requiring planning permission, under the usual rules of permitted development. This will make adding a two-storey extension to your home no more complicated than having a loft conversion. This doesn’t mean that there is no paperwork involved in undertaking a two-storey extension, but it will make obtaining permission for the extension much simpler.

Loft Extensions: Roof extensions/should be set back, as far as reasonably feasible by at least 20cm from the eaves, unless it is a hip or gable roof (measure the 20cm along the plane of the roof). The roof extension should not hang over the wall of the house.To be a Permitted Development any additional roof space created must not exceed these volume allowances: 40m3 on terraced or emi-detached houses, 50m3 on detached houses.

If you believe that your property falls under permitted development, the best way to ensure a positive result is to consult the advice of an Architect to ensure that your extension follows these rules which are applicable to all extensions:

  • Materials should match the existing house
  • No raised platforms, balconies, or terraces
  • Single storey extensions should not be more than 3 meters high
  • Must not be taller than the existing building
  • The extension should not take more than 50% of garden space

Permitted Development Rights are a set of policies which allow homeowners greater freedom to add value to their home whether it’s increasing your property price or simply to add floor space. By acting upon these rights you can extend your property to a certain degree, without the need for Full Planning Permission, which can be a more expensive and time-consuming process, as long as you comply with relevant rules.

This generally applies to the single-storey side or rear extensions, loft conversions, front porches, double storey extensions, outbuildings, solar panels, skylights of dormer windows and new windows or doors. However, even Permitted Development has its restrictions and does not cover double-storey extensions, larger loft conversions, flats or properties in conservation areas. Regardless, even if you meet all the requirements for Permitted Development, you will still need to submit your plans to council which they will need to check, and approve.

For a full planning application, you will need good knowledge of the local guidlines, an appropriate design and a full set of accurate architectural drawings. Many London Architects will do drawings but not offer extensive planning advice and submit your application on your behalf. On the other hand, Planning Counsultants have expert knowledge of regulations and can therefore play a vital role in obtaining permission for projects with complex needs, but where do both options leave you after your application has been granted…or refused? At Extension Architecture we understand that planning and building involves a lot of head-scratching, that’s why we guide you through the whole process, every step of the way. Extension Architecture specialises in design AND planning consulting and do not charge for submission and liaison with the council. We design, submit planning applications, building regulations with our in-house engineer, construct with trusted buiilders and offer creative interiors with our very own kitchen range. Why bother with the hassle if we can do it all for you?

Building Regulation drawings and control are very important because they insure the safety of people in buildings. Building approval means that your building complies with the national set of standards to protect people’s health and safety in and around buildings. Some examples of what building regulations include are structural calculations, fire-safety, insulation, damp-proofing, foundations, heating, ventilation and accessibilty. Once you have received planning permission, building regulation drawings will have to then be submitted and approved before you can start construction. Just remember, cow-boy builders are always risky business and Local authorities have power under the Building Act 1984 to enforce non-compliant building work altered or removed.

Whether you are considering an extension, a plot development or a conversion, we are here to assist you in gaining LPA approval, maximising the potential of your project which in turn increases the value of your home. At Extension Architecture we offer bespoke packages to suit your budget, ensuring you get the perfect solution for you.

We always provide 2D architectural drawings which detail the design in question. In more complex cases, we can provide 3D visualisations to bring your concepts to life and accurately display the proposed works.

A site assessment will be carried out, either in person or remotely, which will gather information on the existing site. After this, initial drawings are produced and options are discussed with our consultants which leads to amended drawings being made until both parties are happy. At this stage, the application is submitted to the local authority.

All you need to do is fill out our online form which provides us with more information about your project, this way we can get back to you with a more accurate quote. If you would prefer to speak to one of our planning consultants directly, you can call us on 0203 409 4215.

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