Industry Experts in Home 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 suited to your taste and budget.
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
Bespoke Design & Planning
Over 16 Years of Experience
Free Consultation & Itemised Quotes
Full Cost Transparency & Project Management
Insurance Backed Warranty
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.
A standard loft conversion is a brilliant way to add functional space to your home, and is ideal for a bedroom, office space or a reading room. This type of conversion will generally cost between 45-49K based on factors such as the size of your property, roof height or elements such as types of stairs you wish to include.
Apart from a standard loft conversion, you also have the option of opting for other types of loft conversions to suit your needs.
A double mansard loft conversion which adds more space to both the front and rear end of your property will cost around 48-53K.
We also design and build L shaped extensions that can even be converted into another master bedroom. The price will depend on whether you prefer the extension with a half back addition or a full back addition which ranges from 55-60K and 60-65K respectively.
Alternatively, you can also opt for other designs such as Hip to gable loft conversions, Veluxe loft conversions and more.
You can also add a side return extension or rear extension to your home that will both expand your living space as well as add value to your home and property.
The cost of a rear extension which you may open out into the backyard or use as a spare room will range from 52-55K while a Side infil extension and Side return extension may cost around 60-65K and 70-75K respectively.
Our team of experts are also well experienced in creating functional and also luxurious kitchens that are perfect to accommodate your entire family, entertain friends or for family dinners.
The cost of a kitchen extension may depend on the size, style and extent of remodelling that you may wish to carry out. Roughly a 4m Kitchen extension may cost around 60-65K while a 6m Kitchen extension may vary from 75-80K.
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.
Featured Projects
Fulham
Orbain Road SW6 7JZ
This project was completed in 2023 and the approximate budget was £101,000.
Learn more
Lambeth
Hetherington Road SW4
We completed this stunning project for our client Angus in Lambeth.
Learn more
Teddington
Station Road SW4 7PA
We completed this exciting project for our clients on Station Road, a quaint residential area in the heart of Teddington.
Learn more
Leyton
Windsor Road E10
We completed this kitchen extension on Windsor Road, a charming residential street nestled in the heart of Leyton.
Learn more
Clapham
Hydethorpe Road SW12 0JF
We did this kitchen extension project for our clients in Hydethorpe Road SW12.
Learn more
Fulham
Orbain Road SW6 7JZ
This project was completed in 2023 and the approximate budget was £101,000.
Learn more
Lambeth
Hetherington Road SW4
We completed this stunning project for our client Angus in Lambeth.
Learn more
Teddington
Station Road SW4 7PA
We completed this exciting project for our clients on Station Road, a quaint residential area in the heart of Teddington.
Learn more
Leyton
Windsor Road E10
We completed this kitchen extension on Windsor Road, a charming residential street nestled in the heart of Leyton.
Learn more
Clapham
Hydethorpe Road SW12 0JF
We did this kitchen extension project for our clients in Hydethorpe Road SW12.
Learn more
What Our Clients Say
Thank you to Amol and his entire team
“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”
Lisa
Twickenham TW2
Thank you Good Design & Build…
“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.”
George Banks
Richmond TW10
I would like to thank GDB…
“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”
Debra
Mortlake SW14
My wife and I would like to say a huge thank you
“My wife and I would like to say a huge thank you to all the team at Good Design & Build. From the planning stage all the way through to completion they were meticulous with their design and helping us achieve our vision of our dream family home. We were supported all the way through, even when we wanted to make significant structural changes during the build. We are over the moon with the results achieved and quality of the building work and finishing is excellent. THANK YOU GOOD DESIGN & BUILD!!”
Xerxes Dalal
Potters Bar EN6
Good Design provided the architectural services
“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.”
Louise Murray
Twickenham TW1
We thoroughly enjoyed working with Amol
“We thoroughly enjoyed working with Amol and the Good Design & Build team on our recent house extension. We've been so happy with how the team helped design, plan and deliver the extension. Always very patient and informative of how the process will run, the team did a fantastic job and we're delighted with the results. The biggest compliment I can give them is that I'd happily work with Amol and the team again :).”
Benjamin Hammond
Twickenham TW11
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 StartedBuild 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