Design & Build London

House Extension Design and Build services in North London and Hertfordshire

Design & Build house extension service is an innovative concept for home-owners in London and Hertfordshire who want to add extra space to their existing home. It has many benefits, including easier communication with architects and building specialists, as well as saving you time.

Our award-winning architects and qualified structural engineers have years of experience designing all types of single and double-storey home extensions for both newer and period properties. Our Design services include planning, architectural and structural drawings and obtaining planning permission.

If you then decide to go ahead with our London building company to complete the build, our builders extensions specialist will take care of the construction from start to finish. Our dedicated project manager will keep you updated throughout the whole building process and will answer any questions you might have. Our Design and Build team works hard to turn your vision into reality with minimal disruption to your daily life.  

Our Design and Build process step by step

  1. Discussing your plans with the architect
  2. Site visit
  3. Extension design
  4. Planning the build
  5. Construction
  6. Completion
House extension design and build - 3d drawings


Discussing your plans with the architect

After you submit an enquiry for your design and build project, one of our architects will give you a call to discuss your plans. They will then send you a price quote for preparing a complete set of architectural and structural drawings.

Site visit

If you are happy with the quote, the architect will arrange a visit to your property so that he can have a good picture of what you want to achieve.

During this no-obligation meeting, our qualified architect will respond to any queries you may have regarding your extension plans or the design process.

Extension design

After you have approved the initial design concepts, our architect will work closely with you to prepare detailed extension drawings and floorplans, ensuring that the final design meets your requirements.

Our architects can also generate a 3d Auto Cad model of your extension. This step cost a little extra, but it helps you get the best idea of how your complete extension will look. 

House extension design and build - completed wrap around extension


Planning the build

Before the construction begins, we will arrange another site visit and will then provide you with a detailed cost breakdown for the build. If you decide to go ahead with our building team, we will prepare a work schedule showing the starting and completion dates for each aspect of the build.


The construction will be carried out by a team of skilled builders. An experienced on-site Project Manager will oversee the work and will keep you updated on every step of the building process. During the construction, a building inspector will make regular visits to see that our building team adheres to all the latest Building Regulations.


After we complete the construction of your new home extension, our talented London interior designer can help you choose the right colours, textures and materials for your new room. Our team of skilled painters and decorators will then turn your vision into reality by finishing the interiors to the highest quality.

We will then provide you with a ten-year structural warranty, the completion certificate issued by the building inspector, and other vital documents.

Why choose our Design and Build Company

Our skilled team has years of experience designing and constructing luxurious house extensions in London and Hertfordshire. We have built lasting relationships with our clients, who often recommend us to their friends and family and are happy to provide references. 

We have extensive experience in with house refurbishment in London and Hertfordshire. Over the years, we have built excellent relationships with suppliers and can assist you with getting kitchen units, fittings and finishes at a discounted price.

Because we work closely with the architect, you will be able to make small changes to the design, such as changing the type of flooring and minor layout alternations, even after the construction has commenced. 

Our design services come with no obligation. If for any reason you decide not to have your extension built by our building company after our architect completes your extension drawings, all you have to pay is the architect's fees as per their original quotation. 

Enquire now
  • 183 Edgware Road
  • London
  • NW9 6LP


0208 205 8173  
Mon to Fri 09:00 - 17:00

We operate across North London, North West London and Hertfordshire including BarnetBorehamwood, Bushey, Camden, Edgware, Finchley, Hampstead, Hendon, Islington, KensingtonMill Hill, Potters Bar, St AlbansStoke Newington, Swiss Cottage, and Watford