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Industry Experts in Home Extensions, Kitchen Extensions and Loft Conversions - Customised for your Budget and Unique Style

We at Good Design and Build are industry experts in creating beautifully elegant spaces that you will love. From adding an extra room for your growing family or converting your loft to extending your kitchen, we have you covered!

With a great eye for detail and spaces built to the highest specification, we offer designs with a clear understanding of your taste as well as your budget – whether it’s managing the cost of your loft conversion, planning for the cost of a house extension or ensuring the kitchen extension costs stays within your means, our team will ensure that the project is delivered based on your needs without compromising on quality or style.

Loft Conversions

Velux Loft Conversion

Velux loft conversion includes installing Velux windows in the loft space without making any structural changes. This allows the natural light to flood in and make the space bright and fresh, perfect for a modest bedroom, reading nook or even a home office.

Estimated Cost
Starting from £35K

Dormer Loft Conversion

A Dormer loft conversion involves constructing a box-shaped extension on a slanted roof, resulting in walls that form a right angle with the floor. This clever addition not only increases the available headspace but also expands the overall floor area.

Estimated Cost
Starting from £50K

Double Mansard Loft Conversion

A double Mansard loft conversion is the most spacious and extensive option available. This type of conversion involves constructing both a front and rear Mansard, adding an entire new storey to the property.

Estimated Cost
Starting from £65K

L-Shaped Mansard Loft Conversion

Create a truly unique living space with an L-shaped mansard loft conversion. This innovative design combines the elegance of a mansard roof with the versatility of an L-shaped layout, offering abundant floor space and a distinctive architectural feature for your home.

Estimated Cost
Starting from £70K

Hip to gable Loft Conversion

A hip to gable loft conversion is well-suited for end of terrace and detached houses. This type of conversion involves altering the inwardly slanted end roof of the house to create a vertical wall. By doing so, the original hip roof is transformed into a gable roof.

Estimated Cost
Starting from £65K

L-Shaped Loft Conversion with full back addition

An L-shaped Mansard conversion involves the construction of two mansard builds that are interconnected. Typically, one Mansard is built on the rear outrigger roof, while the other is constructed on the main roof, resulting in the distinctive L-shape of this type of conversion.

Estimated Cost
Starting from £75K

Half L-Shaped Loft Conversion

In an L-shaped loft conversion, two dormers are constructed and joined together. One dormer is built as a flat roof extension over the main portion of the roof, while the other dormer is positioned at the rear, covering half of the roof area. This creates a unique half L-shape when observed from above.

Estimated Cost
Starting from £65K

L-Shaped Loft Conversion With Balcony

An L-shaped loft conversion involves the construction and connection of two dormers. One dormer is built over the main part of the roof, while the other dormer is positioned at the rear, covering one half of the roof area. Additionally, the other half of the roof is transformed into a balcony, adding an outdoor space to the conversion.

Estimated Cost
Starting from £70K

Kitchen Extensions

Small Rear Flat Roof

This conversion builds a terrace kitchen extension with a flat roof. They are ideal for terraced or semi-detached homes. Flat roofs are more cost-effective. These usually extend the ground floor space of the outrigger.

Estimated Cost
Starting from £45K

Large Rear Pitched Roof

This rear extension has a sloping roof for better aesthetics. Skylights bring in more natural light, and bi-fold doors open onto the garden. The larger floor space offers more living space options.

Estimated Cost
Starting from £60K

Large Rear Flat Roof

It is a rear extension with a flat roof, which is economical in design. Using skylights will bring plenty of natural light to the new addition. Bi-fold doors seamlessly connect the addition to the garden.

Estimated Cost
Starting from £60K

Large Rear Single Pitched Roof

Double the visual impact with the roof design for your rear extension. It is both modern and suitable for period architecture. Entertain your guests in an open-plan kitchen or a perfect orangery with oversized skylights.

Estimated Cost
Starting from £70K

Large Rear Double Pitched Roof

This extension offers a more polished roof design, which blends seamlessly with existing period architecture. With extensive glazing, you can create a quiet sunlit sitting room for your kitchen well-connected to the outdoors.

Estimated Cost
Starting from £70K

Small Side Infill Flat Roof

Harmonise your Victorian floor plan with this easy extension. This infill can extend your kitchen or even become a utility room. Perfect for smaller properties, a flat roof ensures less build work.

Estimated Cost
Starting from £50K

Medium side infill flat roof

Utilise the awkward space of the side return of your Victorian home to add extra space to the rear of the property. A flat roof with skylights offers natural light and even head height.

Estimated Cost
Starting from £60K

Large Side Infill Flat Roof

It offers plenty more space for a larger kitchen, a bathroom, a home office, or a garden room. Increase your Victorian home's square footage by unifying the old configuration for a practical, livable space.

Estimated Cost
Starting from £75K

Small Side Infill Pitched Roof

Incorporate a sloping roof into your infill to complement your home's period architecture. Skylights offer natural light and extend your kitchen without using any main garden space. Ideal for small side returns.

Estimated Cost
Starting from £50K

Medium Side Infill Pitched Roof

Extend your kitchen in style or create a small dining area. It offers a versatile space by seamlessly integrating redundant space at the back of your Victorian home. A pitched roof enhances the aesthetics.

Estimated Cost
Starting from £60K

Large Side Infill Pitched Roof

Transform your kitchen area with an open-plan layout. Harness more natural light with skylights and create a bigger kitchen, dining area, bathroom, utility room, home office, home gym, or lounge area.

Estimated Cost
Starting from £75K

Rear & Small Side Infill Pitched Roof

Fill in the side return and build a small rear extension at the same time. Add double the space and save money. A pitched infill roof and flat rear roof prevents a boxed-in design.

Estimated Cost
Starting from £60K

Rear & Medium Side Infill Pitched Roof

Add more square footage to your period home by extending to the side and the rear. Our pitched infill roof enhances visual appeal, and the flat rear roof is practical and modern.

Estimated Cost
Starting from £70K

Rear & Large Side Infill Pitched Roof

A larger Victorian property can boost its value with a more usable floor area. Make use of the underutilised side return for infill and create a rear addition in one project.

Estimated Cost
Starting from £80K

Small Wrap-around Single Pitched Roof

Join your infill and rear extensions for a wrap-around. The single-pitched roof makes the addition visually appealing. Skylights create a light-filled large space perfect for open-plan living.

Estimated Cost
Starting from £65K

Medium Wrap-around Single Pitched Roof

This extension offers two living spaces or one large kitchen area with plenty of room for modern entertaining. The single-pitched roof design saves money while maximising style with natural light from skylights.

Estimated Cost
Starting from £75K

Large Wrap-around Single Pitched Roof

Discover optimal floor space for your ground floor with a roof design that is not too tricky but big on style. Create multiple rooms or living areas that blur into the garden with oversized glazed doors.

Estimated Cost
Starting from £95K

Small Wrap-around Double Pitched Roof

Tiny space? No worries. The double-pitched roof design makes up for the small size with a space-maximising look. Go bold on elegance and create a stunning extension that creates uniform space at your home’s rear.

Estimated Cost
Starting from £65K

Large Wrap-around Double Pitched Roof

Sunlit rooms or one big living area for all your loved ones to gather. Explore all the possibilities with this extension. Reconfigure your floor plan or extend your kitchen for the ultimate open-plan experience.

Estimated Cost
Starting from £80K

Medium Wrap-around Double Pitched Roof

A polished look for your period home extension will only increase its value. The double-pitched roof wrap-around can blend in or stand out as you wish. Plenty of room for entertaining or family entertainment.

Estimated Cost
Starting from £95K

Small Wrap-around Flat Roof

Functional spaces with a practical design. Give your wrap-around a minimalist profile. Join a side infill with a rear extension to create a unified space. Incorporate more glazing for space-enhancing ambience.

Estimated Cost
Starting from £50K

Medium Wrap-around Flat Roof

Cost-effective design with cleaner lines for contemporary spaces. An infill and a rear extension join to form a wrap-around. Extend your kitchen and add a stylish dining room well-connected to the outdoors.

Estimated Cost
Starting from £70K

Large Wrap-around Flat Roof

This addition combines a side return with a rear extension. The flat roof is economical to build, and the skylights bring in plenty of natural light. Maximise your extension capacity for spaces that set you free.

Estimated Cost
Starting from £90K

Loft Conversions

Bespoke Design & Planning

Over 16 Years of Experience

Free Consultation & Itemised Quotes

Full Cost Transparency & Project Management

Insurance Backed Warranty

Frequently Asked Questions

We’re committed to delighting our clients, as much with our approach as with our solutions. Our values run through every aspect of what we do – from the moment you commission us, to the moment we hand over the keys.

There are many different types of loft conversions and home extensions that we offer depending on your property and budget. In terms of loft conversions, you have the choice of selecting a standard loft conversion as well as other additions such as a roof terrace or a skylight. Furthermore, you can also expand your home through Double Mansard loft conversions, dormer loft conversions or even include a pod room.

A home extension will also allow you to expand other areas of your home such as the kitchen or garage. Please note that the overall house extension costs can depend on your specifications, but we will work with you to ensure the project stays within your budget. For instance The cost of pod extensions and utility room extensions may vary based on the size of the area, features, materials and style you opt for.

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.

Featured Projects

Harlesden

Sellons Ave NW10 4HJ The project included creating a master bedroom in the loft with an adjoining .

Fulham

Orbain Road SW6 7JZ This project was completed in 2023 and the approximate budget was £101,000.

Lambeth

Hetherington Road SW4 We completed this stunning project for our client Angus in Lambeth.

Testimonials

Testimonials from Our Trusted Clients

“Thank you to Amol and his entire team for delivering us a fantastic extension to our newly purchased home. The guys were friendly and very professional during all stages”

Sarah M.
Sarah M.

Homeowner

“Originally, we’d planned on this being a property to rent out to others. Since the loft conversion, we’ve fallen back in love with the place – and have now decided to move back here.”

James K
James K

Business Owner

“I would like to thank GDB for all of their hard work, ideas and inspiration and for being so approachable and easy to deal with during the our rear extension. I would happily recommend them to anyone thinking of starting a building project”

Linda T
Linda T

Property Developer

“Good Design provided the architectural services as well as building work. It was great to have both bundled into one. They were very flexible and great to work with - nothing was too much trouble. I would highly recommend them.”

David L
David L

Green Building Advocate