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Nestled in West London, Hillingdon is home to the infamous Brunel University and Thorpe Park Resort, Bushy Park, The Savill Garden and Cassiobury Park sets a breathtaking landscape to Hillingdon. The historic towns of Hayes, Ruislip, Northwood Hills, West Drayton and Uxbridge form the borough of Hillingdon offering you a glimpse of ancestry and heritage in a now modernised suburb. Hillingdon is also recommended as one of the safest places to live in London. Building your abode in a culturally rich suburb such as Hillingdon requires mastery and finesse  which Good Design & Build house extensions Hillingdon can offer you with our best-in-the-trade architects and builders. 

Side Return – A feature of Victorian and Edwardian properties is the side alleyway which is left out from the real extension that can be converted to a Side Return. Despite its ordinary use as a kitchen extension, once the interior walls are knocked through, the space can also be utilised as a diner, reading nook, workspace or a shower room.

Rear Extension – Extending the rear end of your home offers you the benefit of a back garden with extra space and good natural lighting along with fresh air. With garden views, it creates the ideal dining area, and if you can spare some floor space, a guest bedroom that doubles as a sitting room too.

Wraparound – if you want the best of both worlds, opt for a Wraparound Extension that connects a Side Return with a Rear Extension to form an L-shaped space that adds more functionality and elegance.

Double-storey Extension – How do you multiply floor space with the same roof and foundation? Choose a two-storey addition that offers space for upstairs rooms, terraces, and pod installations.

Loft Conversion – when you extend your home, incorporate a loft conversion that can help you save garden space and make use of a high attic. From a double-mansard to a dormer, loft designs allow for double bedrooms, en suites, bathrooms, home offices, playrooms, and more.

House extensions have permitted development rights, which means they do not require planning permission. However, if your extension is not within the following guidelines, you will need to seek approval for your plans.

  • Only 50% of the land around the original house contains extensions.
  • A conservatory cannot exceed 3m and 4m respectively from the original rear wall of terraced/semi-detached and detached property.
  • Extensions are no higher than the highest part of the original roof or higher at the existing eaves.
  • The height of a single-storey extension is limited to 4m.
  • The width of a Side storey extension cannot exceed 50% of the full width of the original property.
  • Single-storey Rear extensions should not extend beyond the property’s rear wall by more than 6m if semi-detached or terraced or by 8m if detached.
  • Two-storey side-facing windows must be obscure-glazed and any opening 1.7m above the floor.
  • There can be no alterations to the roof of the original house.
  • Roof pitch must match the existing as far as possible.
  • House extension ideas for homes around Hillingdon.
  • Glamour up your home space with innovative and simple techniques which can invigorate your perspective and offer you relaxation. 
  • A glazed Side Return roof with glass beams affords more daylight than skylights if you want to brighten up the room even more. A melding of toughened glass layers provides load-bearing capability, and glass beams contribute to a frameless look.
  • Loft conversions are the next best thing if adding an extra storey to your single-storey extension doesn’t get planning approval. When it comes to creating children’s bedrooms, these can be more fun and keep the noisy playtimes away from the main living areas.

We, at Good Design and Build offer our superior-quality services in the Hillingdon area, where we have gained expert insights into planning requirements and the properties that benefit the most from extensions. A team of expert architects, engineers and builders tailor and create designs that are unique to you. Only the best materials, fittings and fixtures are utilised and a strict schedule is maintained to finish work on time. All extension projects we undertake have project managers appointed by us, and they ensure the highest standards prevail from start to finish. There are easy payment plans for all our services, and we offer complete cost transparency. We assist with Party Wall Agreements and apply for planning permission on your behalf. A two-stage contract gives you the flexibility to choose to stay with us for the journey or not.

Side Return Extension costs around £35,000

The cost of a Rear Extension starts from £40,000 up.

Wraparound Extension can cost £55,000 and upwards

Double Storey Extension costs £75,000 and above

Please feel free to use our free initial design consultation for a wide range of home improvement services, including conversions, renovations, and extension projects in Hillingdon.

Don't move. Extend in style

We can save you the hassle that comes with moving not to mention the heavy stamp duty! Adding an extra loft bedroom or enlarging the living kitchen dining space on ground floor is an economical way of transforming your home to suit growing needs. The projects can range from £40-100K depending on your requirements and can be completed within 8-16 weeks.

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How we deliver projects

Our process is simple and divided into two distinct phases with separate contracts: Design and Build. As a client you only commit to one phase at a time depending on what stage of the process you are in. Each phase consists of three stages as described below.

1. Design

This is the kick-off point for your project. We carry out a complete architectural measured survey of the property. This allows us to create accurate CAD design drawings. This is followed by a design meeting to start discussing your ideas in more detail.

2. Planning

At this stage we finalise the designs with you and start preparing planning applications as needed. We place a high priority on ensuring that plans, designs and schedules are all based on a thorough and detailed understanding of planning guidelines. We co-ordinate with local authorities until the decision is made, and the planning approval is secured.

3. Technical

Once the planning consent is secured, we translate the design drawings into more detailed technical drawings for the purposes of building control and construction. This also includes specifications and structural calculations. At this stage, we will also submit to you our ‘no obligation’ quote for the build phase.

4. Pre-build

90% of our clients decide to stick with us after the design phase is completed. Once the build contract is signed, we kick off the process by making sure all the pre-build processes are complete. These include assistance with party wall agreements, Thames Water build over agreement, submitting building control application, and preparing method statements etc as needed. This stage ends with a pre-start meeting with your foreman before the actual build begins.

5. Build

One of our foremen will be dedicated to your project and will be on-site to manage everyday works. Our project managers will be overseeing the works to make sure they are completed to high standards, within your budget and on time. Throughout the process we will keep you updated with the progress and coordinate the works with third parties such as kitchen or flooring suppliers. We will also advise and guide you to choose any suppliers if needed.

6. Handover

As the build draws to finish, we will help to iron out any ‘snags’ to make sure everything is completed to your satisfaction. We will put together all necessary certificates such as gas, electricity and building control completion along with warranties for glazing, boiler etc. At the final completion meeting, we will hand you these documents, together with the keys to your house. Needless to say, you can contact us any time after this, if you want us to look at something.


This is the kick-off point for your project. We carry out a complete architectural measured survey of the property. This allows us to create accurate CAD design drawings. This is followed by a design meeting to start discussing your ideas in more detail.

At this stage we finalise the designs with you and start preparing planning applications as needed. We place a high priority on ensuring that plans, designs and schedules are all based on a thorough and detailed understanding of planning guidelines. We co-ordinate with local authorities until the decision is made, and the planning approval is secured.

Once the planning consent is secured, we translate the design drawings into more detailed technical drawings for the purposes of building control and construction. This also includes specifications and structural calculations. At this stage, we will also submit to you our ‘no obligation’ quote for the build phase.

90% of our clients decide to stick with us after the design phase is completed. Once the build contract is signed, we kick off the process by making sure all the pre-build processes are complete. These include assistance with party wall agreements, Thames Water build over agreement, submitting building control application, and preparing method statements etc as needed. This stage ends with a pre-start meeting with your foreman before the actual build begins.

One of our foremen will be dedicated to your project and will be on-site to manage everyday works. Our project managers will be overseeing the works to make sure they are completed to high standards, within your budget and on time. Throughout the process we will keep you updated with the progress and coordinate the works with third parties such as kitchen or flooring suppliers. We will also advise and guide you to choose any suppliers if needed.

As the build draws to finish, we will help to iron out any ‘snags’ to make sure everything is completed to your satisfaction. We will put together all necessary certificates such as gas, electricity and building control completion along with warranties for glazing, boiler etc. At the final completion meeting, we will hand you these documents, together with the keys to your house. Needless to say, you can contact us any time after this, if you want us to look at something.

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Let's get started with building your own bespoke quote for your dream extension. Tell us as much in detail as possible to get most accurate price.

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Build a Quote!

Let's get started with building your own bespoke quote for your dream extension. Tell us as much in detail as possible to get most accurate price.

Get Started