Bespoke Design & Planning

Over 12 Years of Experience

Free Consultation & Itemised Quotes

Full Cost Transparency & Project Management

Insurance Backed Warranty

Europe’s longest high street is getting its buzz back with a trendy cafe scene, bars, and independent shops. The oncoming surge of developments put Streatham at the top of revival areas in South London. Served by three railway stations, you can be at Victoria in less than 20 minutes. And, on a sunny day, head to Streatham Common for a lovely picnic to commune with nature. But, it’s no picnic upsizing when you need an extra bedroom or two. Loft Conversions Streatham can find that space for you in your attic. Good Design & Build brings creative space maximisation to your home improvements with innovative designs and sound craftsmanship. 

A loft conversion is a cost-effective solution for extending a property’s livable floor space, particularly in urban areas, where the prospect of upsizing often comes with a staggering price tag. Instead of expanding the property’s footprint, it builds upwards. The process involves transforming the neglected attics into habitable spaces. These include bedrooms, bathrooms, home offices, playrooms, gyms, and even art studios. Typically, a loft conversion alters the roof structure and adds flooring, roofing, ceilings, windows, doors, and staircases. Adding insulation to the loft can also make your home more energy-efficient. A high-quality loft conversion adds value to your property, boosting the resale price of your home.

Rooflight Conversion – Also called a Velux Conversion, this simple design installs roof windows or skylights onto the existing roof slope without changing the roof structure. These windows make the room habitable, bright, and airy. 

Dormer Loft Conversion – Extends the current roof vertically, creating additional floor space and headroom within the loft. Dormers typically have a flat or pitched roof and can include windows, offering more usable space. 

Mansard Loft Conversion – This usually involves transforming an entire roof plane, resulting in a generous living space. It alters the roof slope to build a near-vertical wall, sloping at 72 degrees, with a central flat roof. A double mansard can give a property the appearance of a separate floor. 

Hip-to-Gable Loft Conversion – Ideal for semi-detached, end-of-terrace and detached properties with hipped roofs, especially those built in the 1930s. It replaces the hip section of the roof with a gable. Hipped roofs can limit the usable floor area within a loft space. The extension of the roofline generates extra space for functional living areas.

L-shaped Loft Conversion – Combines two dormers to maximise space. Typically, a larger dormer is placed on the main roof, while a smaller one gets built on the rear outrigger, a prominent feature in Victorian or Edwardian homes. This loft conversion type optimises space, particularly for terraced or semi-detached properties.

The cost of loft conversions in Streatham varies based on the type of conversion and its size. While more straightforward designs cost less, complex features can increase your budget. Committed to complete cost transparency, we offer you a free itemised quote to get started.

Room in the roof conversion (basic) –  £35,000

Dormer loft extension – £50,000

Mansard extension – £60,000 – £65,000

Hip-to-gable extension – £65,000

L-shaped extension – £65,000 – £75,000

Converting your loft isn’t just about creating additional space. It is an opportunity for you to increase the value of your property with an elegant design, modern comforts, and space maximisation. Balancing each aspect by yourself can give way to errors and pitfalls. 

It requires a loft conversion specialist with expertise, able to craft pleasing spaces that seamlessly integrate with your property, all within the law and your budget. 

Proficiency in local building and planning regulations ensures the project is compliant, and there’s no risk of potential lawsuits that may undo your hard work. Entrust your project to the right people for the right effect.

We have years of experience in high-quality loft conversions for Victorian and 1930s properties throughout London. Our design-centric approach is bespoke and value-adding. We have a team of architects, structural engineers, project managers, and skilled builders who combine their expertise to seamlessly integrate modern living areas into your home’s layout, enhancing its visual appeal and functionality.

Our contemporary designs prioritise natural light and modern layouts. For an immersive visualisation of your space, we bring our designs to life with the latest 3D technology. 

We ensure our designs comply with local regulations and handle planning permission and building control applications on your behalf. At Good Design & Build, we provide comprehensive project management services from conception to completion. Additionally, we maintain partnerships with trusted third-party suppliers to source the finest products that your budget can afford. Our products come with an insurance-backed warranty.

The loft conversion cost depends on two key factors: the type of loft conversion and its size. Different property types and conversion designs require varying degrees of build work and material. More extensive structural alterations and intricate designs add to the cost. 

However, opting for tailored, bespoke solutions can help manage costs effectively. Our design team is readily available to provide expertise in crafting cost-efficient loft conversions that are custom-designed to align with the unique characteristics of your property and your specific requirements.

We provide complete loft extension solutions, from architect-drawn bespoke designs to ironing out snags at completion. As part of our full service, we offer assistance with party wall agreements and Thames Water build-over agreements. We prepare method statements and submit planning permission and building control applications. Additionally, we leverage partnerships with third-party suppliers to guarantee that you receive top-quality products at the most competitive prices.

Loft conversions fall under permitted development rights and usually do not require planning permission. However, there are limitations to these rights. Living in a conservation area or a listed building may require planning permission for your project. Rest assured, our team is well-versed in planning regulations and local ordinances to ensure full compliance with the law.

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.

What Our Clients Say

Featured Projects

GET YOUR FREE EXTENSION
QUOTE

    Loft ExtensionKitchen ExtensionBothFull Refurbishment
    ASAP3 - 6 months1 - 2 years
    £50 - £75K£75 - £150K£150 - £250K£250K plus

    GET YOUR FREE EXTENSION QUOTE

      Loft ExtensionKitchen ExtensionBothFull Refurbishment
      ASAP3 - 6 months1 - 2 years
      £50 - £75K£75 - £150K£150 - £250K£250K plus