Bespoke Design & Planning

Over 12 Years of Experience

Free Consultation & Itemised Quotes

Full Cost Transparency & Project Management

Insurance Backed Warranty

This thriving, vibrant southeast London suburb is complete with a bustling high street lined with an array of independent stores. The lovely Danson Park is at its doorstep, where boating lake, picnics, and playground activities sort your weekend out. Excellent schools are nearby, and easy road links connect you to Central London and the surrounding areas. It is a family-friendly town, but isn’t your home? Loft Conversions Welling is your answer. Good Design & Build offers bespoke solutions that create exceptional spaces.

A loft conversion is one of Britain’s most popular home improvement methods to increase the usable living space without altering the building’s footprint. It is the most cost-effective way to upsize in urban and suburban areas, where space is often limited and expensive. Period homes are ideal contenders for loft conversions as their lofts are generous in proportion.

The unused or underused loft space is either uninsulated or poorly insulated, leaking heat and giving rise to higher energy bills. A loft conversion also makes your home more energy-efficient by insulating it well for a functional living space.

A professionally carried-out loft conversion with clever space-saving solutions and modern comforts can enhance property value. The converted loft can accommodate various usable spaces like bedrooms, bathrooms, en suites, home offices, playrooms, studios, or other areas. There are different types of loft conversions to choose from.

Rooflight Conversion – also known as Velux conversion, involves the installation of roof windows or skylights onto the existing roof slope. These windows allow natural light and ventilation into the loft area, making it habitable. It is only suitable for lofts with sufficient head height.

Dormer Conversion – this type of loft conversion extends the existing roof vertically, creating additional head height and functional floor space. Dormers typically feature either flat or pitched roofs and include windows. These conversions are a common sight in London neighbourhoods.

Mansard Conversion – entails changing an entire roof plane to create a spacious loft area. It features a nearly flat roof with the back wall sloping at an angle of 72 degrees. Due to the significant alterations to the roof structure, Mansard conversions often require planning permission. They are suitable for terraced, semi-detached, and detached homes.

Hip-to-Gable Conversion – the design is ideal for properties with hipped roofs that inhibit usable space. It involves replacing the sloping sides of the roof with vertical walls (gables). The extension of the roofline creates additional head height.

L-shaped Conversion – achieved with two dormers joined together to double up space, with one dormer positioned on the main roof and the other on the rear outrigger. This type of loft conversion is suitable for Victorian properties with rear outriggers.

Loft conversion cost depends on the type of conversion chosen, the size of the area getting converted, the structural changes involved, and design features. Our pricing is fully transparent, and there are no hidden fees. We offer free itemised quotes and consultation to help you decide the best loft conversion type for your home and needs.

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

Loft conversions don’t just create extra space in your home; they also serve as significant upgrades that can substantially increase your property’s value. With elegant designs, space-maximising techniques, and superior construction, you can increase the resale value of your home. A well-conceived, stylish design with smart space utilisation is critical for your loft conversion to meet desired expectations and to make the most of your money.

Employing a conversion specialist ensures seamless integration of modern living spaces into your home’s layout, elevating aesthetic appeal and functionality. Home remodellers are fluent in local building and planning regulations, ensuring your loft conversion is lawful and built to recommended standards. Instead of opting for a DIY project, entrust your loft conversion to the right team that can deliver exceptional results and go above and beyond your aspirations.

We are specialist Victorian and 1930s home remodellers with years of experience transforming loft spaces throughout London, including the wonderful Welling. Design-dominant in our creative process, we seek to achieve architectural superiority with naturally illuminated and versatile contemporary spaces. All our designs adhere to local laws and building regulations. We have a loft conversion team consisting of architects, structural engineers, project managers, and trained builders who work together to build stylish spaces that seamlessly integrate into your home.

To offer you a more immersive experience, we employ the latest technology to generate 3D designs. We undertake planning permission and building control applications, prepare method statements, and assist with Party Wall Agreements. A diligent project manager is at your service to ensure build work is completed efficiently and up to standard.

We work with reputable third-party suppliers to source the best materials and products your money can buy. Our completed projects across London are a testimony to the high standards we uphold in both quality and innovation.

The cost of your loft conversion depends primarily on two key factors: the type of conversion you opt for and the size of your loft space. We work with bespoke designs tailored to your property and your needs, which can effectively slash unnecessary costs.

We provide complete solutions from design to construction. With architect-drawn bespoke plans, we deliver high-quality designs that create elegant spaces. Our planning specialists collaborate closely with local authorities to acquire the necessary planning permission. We also assist with Party Wall Agreements and Thames Water build-over Agreements. Our team prepares method statements and assists with other pre-construction requirements and legal obligations. We work with external suppliers to ensure you receive the best deals for high-end products.

You can build a loft conversion without planning permission, as it is a permitted development. However, some loft conversion types and design components need planning permission. Living in a conservation area or a listed building alters your permitted development rights. We draw up plans per planning requirements, and when planning permission is necessary, we fulfil the requirements to secure it.

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

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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.

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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