Bespoke Design & Planning

Over 12 Years of Experience

Free Consultation & Itemised Quotes

Full Cost Transparency & Project Management

Insurance Backed Warranty

Price Match for
Like-For-Likes Quotes

Loft conversion

Loft conversion costs in London are £40,000 to £70,000 on average excluding VAT and fees. The costs will vary depending on the size and complexities of the conversion.

Good Design & Build loft conversion costs are as follows:

Room in the roof conversion (basic) – £1,150 – £1,350 per square metre

Dormer loft extension – £1,250 – £1,450 per square metre

Mansard extension – £1,500 – £2,500 per square metre

Hip-to-gable extension – £1,500 – £2,500 per square metre

Change of roof structure – £1,350 – £1,550 per square metre

Generally loft conversions fall under permitted development and you do not need planning permission. Although this may not apply to certain properties that are in conservation area or the loft conversion needing to raise the ridge height. You can find more information here.

Not at all. The old water tank can be decommissioned by our qualified plumbers. Chimney can either be boarded out or totally removed to create more floor space depending on your requirement.

You can easily check this if you have loft access hatch and ladder. Try and measure the distance from top of your first floor ceiling joists to the underside of loft ridge timber. You need minimum 2.5M to achieve the floor to ceiling height of 2M which is minimum requirement. If your loft height falls short of 2.5M, you my need to drop the first floor ceilings to achieve minimum height.

It normally takes approx. 8-10 weeks to complete a loft conversion depending on the type and size.

If your property is suitable for a dormer loft conversion and you are in the need of extra space in the house, you should definitely consider the loft conversion. It is the most economical way to maximise the potential of your property and create more space without having to move.

Loft conversion is the best way to add value to your property. Recent research carried out by the Nationwide Building Society has stated that a loft conversion could add up to 20% to the value of your home. If your property is valued at £500,000, that’s a whopping increase of up to £100,000!

Simply put – YES. Lot conversion is cheaper and less disruptive as compared to an extension which involves foundation, brickwork, etc. Loft project usually requires a steel and timber construction which is quick and economical.

Yes, they certainly do. Research carried out by Nationwide UK confirms that the property price increases as a result of converting your loft. Loft conversions create extra usable space. It makes your property more appealing to buyers. Extensions, which comprise a double bedroom and bathroom can add 20% to the value. One extra bedroom can raise the value by 10%, while an additional bathroom can increase property value by 5%.

Yes, it’s possible. While Victorian and 1930s properties are much easier to convert, new build homes can get the same treatment with extra help. The W-trussed roof of a new build should have the recommended ceiling height of 2.4m to 2.6 m for a loft conversion. By strengthening roof support, sometimes with steel beams, conversions can be accomplished.

There are building regulations on insulation, and they must meet minimum energy efficiency values. If your loft conversion is creating livable space, then, you need warm loft insulation. Insulating over the rafters with tiles, cover cap, and tile battens will create a warm loft. A cold loft, used for storage only, will have insulation between the rafters, often with slab foam.

A minimum of 2.0m roof height is required. If not, raising the roof or lowering the ceiling below will provide the necessary height.

Yes, design-led plans are the most successful, and you can create bespoke designs that fit your home and requirements with an architect’s help. Architects at Good Design & Build provide advanced CAD design drawings for each client.

Kitchen extension

A kitchen extension can be completed as quickly as 8 weeks but can also take approx. 12 weeks. It depends on the complexity of designs, how much internal structural remodelling is required, lead times on glazing, kitchen, etc.

The increased size limits for single-storey rear extensions that were previously time limited and due to expire on 30 May 2019 have now been made permanent by government. So a single storey extension can be done under permitted development or prior notification and does not need a planning application. This is subject to the type of property, whether it’s in conservation area and few other factors. More information can be found here.

You can build upto 3m for terraced property and upto 6-8m for semi detached or detached properties subject to how your property complies with planning regulations under permitted development. See link above.

Kitchen extension prices start at approx. £45K and can go upto £70K depending on size, type and amount of work involved. Things like aluminium bifold or sliding doors, underfloor heating, larger rooflights are common factors that can influence the price of your extension.

Yes, it does. Adding square footage to your home guarantees an increase in property value. A 10% increase in floor space adds 5% to the value. Buyers also find a newer well-proportioned kitchen an incentive. If you have a lovely home but a dated and narrow kitchen, extending it outwards with upgrades certainly make your property more valuable and attractive.

A new open plan kitchen can add 6% to property value. A Single-storey extension with a kitchen and dining area can add 11%. A Wrap Around kitchen can even increase the value by 15%. A double extension with a kitchen and en suite can make your property worth 20% more.

Suitability is the best place to start. Finding out whether you need planning permission is the first requirement. Property inspection by experienced professionals helps identify your choices to extend and suitability to build. Learning about the total cost of each extension early on will help you decide on a budget.

Yes, it is the only way to make sure your plans are well within the recommended guidelines. When you want a bespoke design to fit your requirements, an architect is the best person to draw up that design. Our Design phase is there just for that; to enable a smoother transition to the Build phase with practical and technical designs that complement your house and your needs. These are essential to secure planning consent and for building control and construction.

General design and build

Being an architect led company, our approach is more ‘wholistic’ towards the project. We consider design, space planning, budget, programme and your lifestyle to create bespoke solutions that work for YOU.

As we are a design and build studio, all architectural design services come INCLUDED in our prices. We also offer stand alone all inclusive drawing packages at reasonable rates and we have qualified and friendly team of architects, technicians and structural engineers. Please get in touch to know more.

When you use a design and build company, you eliminate the hassle of dealing with several consultants and sub contractors. You also don’t have to worry about coordinating with all different parties. We take care of all the design, build and management so you can be involved only in the fun decisions! Such as choosing your kitchen, selecting your bathroom suite, flooring, lamps, etc.

Always start by making a ‘wishlist’ and divide it into your ‘priorities’ for your project. We will help you by providing an itemised quote so you can see how it fits with your budget. We offer a transparent specification so there are no hidden costs. This way you always know how to manage your budget.

No. We will make the application and manage it as your agent.

It normally takes 8 weeks for planning to issue a decision.

UK building regulations require every building project to pass inspections and comply with building control requirements in terms of structural integrity, construction quality, electrical and mechanical compliance and certification.

Not at all. We will work with your interior designer. And if you don’t have one, our inhouse interior designer will be at your disposal!

Absolutely. The beauty of our process is that we can jump in at any stage in the project and help you get your dream kitchen extension built. We will work from the drawings you have, even help you to improve them in any way we can.

DIY projects have proven that not everyone gets it right. You can even be facing lawsuits if you don’t follow building regulations and guidelines. It is always safe to leave the tricky parts to an extension company. You can always manage the interiors by yourself. Sometimes, even trying to secure planning permission yourself can fail, and proper assistance is crucial for success.

Usually, no! Home extensions are permitted developments. You need full planning permission if you live in an area of designation or a listed building. Exceeding the limitations and conditions for building needs approval. All Double Storey Side extensions need planning permission. The exterior of the extension should be similar in appearance to the rest of the house.

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

What Our Clients Say

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

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