Single-storey extensions are the perfect solution to many space issues and home improvement projects for modern homeowners. Not only do they create a tailor-made living space for you and your family, they are also extremely cost-effective when compared to the alternative of moving houses.

But even single-storey extensions require a fair degree of planning and detailed designing. It is therefore important to take into consideration the different aspects that are involved in building single-storey extensions to ensure the new extension is a seamless addition to the existing property.

To ensure that the ground floor extension meets all your space and budget requirements, while being elegantly designed and built, it is important to consider some fundamental but crucial questions regarding ground floor extensions. These include:

What is a ground floor extension?

A ground floor extension or single-storey extension is an extension that is built at the same existing level of the house. They are considerably less complex to design and build when compared to multi-storey extensions.

As a result, many of them may fall under permitted developments and do not require planning permission, provided they meet the building guidelines.

Why is a ground floor extension right for you?

When contemplating various home improvement ideas, it is likely that most homeowners search for a design that:

  • Adds space
  • Adds value to the property
  • Adds modernity and elegance
  • Is cost-effective

As such, a single-storey extension may be exactly what is needed. As an added benefit, some single-storey extensions may be constructed without the need for planning permission if they fall under permitted developments.

What are the different types of ground floor extensions?

Ground floor extensions have to be designed taking into consideration the space required, the area available on the property, and the budget.

Most single-storey extensions can be categorised into:

Rear extensions:

As the name suggests, rear extensions utilise the area at the rear of a property. These are extremely popular among homeowners as most properties have considerable rear space available and are also viewed as ideal for kitchen extensions and office pods.

Side return extensions:

Side return extensions are developed using the area that runs along the side of a property and a portion of the rear area. This type of extension is preferred by homeowners as it does not take up too much valuable garden space. Side return extensions are seen as the perfect complement to design indoor-outdoor connections. These are especially useful for increasing living areas, optimising the natural light, and even creating beautiful dining areas.

Wraparound extensions:

Wraparound extensions are designed using the area at the side and rear of a property. They add incredible space and value to the existing house. And can be used for designing home offices, playrooms, utility rooms, and even guest rooms.

What should you consider before installing a ground floor extension?

Whether the changes planned are minor or complex, considerable planning must be done taking into account the different factors that go into designing and building a home extension.

Some of the considerations to bear in mind include:


One of the most important aspects of designing an extension is the space required and the space available on the property. This is particularly vital if the main purpose of the extension is to increase the living space within the property.

This is also important if you want to build an extension within the parameters of a permitted development.

Therefore, a fine balance between the increased living area and the area remaining outdoors must be achieved.


Often, the most vital element of planning an extension is the budget. The budget must be prepared so that it takes into account the size and style of the extension, building materials, fittings and fixtures, specialists’ fees, etc.

A simple ground floor extension costs approximately £1,000 per square metre. But additional costs must also be taken into consideration.

There must also be some leeway allowed for unforeseen expenses such as delays in securing the necessary approvals.

Building materials-

A frequently overlooked aspect of designing an extension is considering the materials to be used. The materials used in the extension affect every part of the process including the design, the budget, future energy bills, and even the planning permission.


Along with these considerations, aspects such as planning permission for the extension and the expertise required also need to be taken into account.

Is planning permission required?

Planning permission is required for any extension that exceeds the specific parameters of permitted developments. The specifications and size limitations for single-storey rear extensions state that:

  • Extensions must not exceed more than 4 metres in height
  • Extensions cannot extend beyond 3 metres from the rear wall of the original house

Similarly, other limitations of size, permitted structures, and buildings materials are listed. Many of these parameters are specific to the type of property and the type of extension planned, so it is best to consult the Planning Portal for guidance on local regulations.

The process for applying for and securing planning permission can take up to 8 weeks depending on the complexity of the extension design. The process involves a comprehensive application which includes detailed diagrams of the proposed extension.

In addition to planning permission, building regulations approval and party wall agreements also need to be taken into account to ensure that the extension build complies with all the building guidelines and regulations.

Should you hire professionals?

Even if you are handy with DIY home improvement projects, it is worth considering hiring a professional team of extension builders. This is because certain aspects of the designing and building work are best left to the experts.

Not only that, but the expertise and guidance that comes from professionals with decades of experience are unmatched. And the value of their work in creating the best possible extension for your home becomes immediately obvious in the extension constructed.

Since many extension specialists work in a team, you do need to hire professionals separately to bring about a cohesive design. And they can provide you with the expertise for every aspect of the extension build. This includes:

  • Inspecting the site and creating detailed diagrams of the proposed extension with structural calculations
  • Creating a cost-effective building design considering your specific budget
  • Applying for and securing the necessary planning permission and building regulations approval
  • Handling all contractual requirements
  • Daily on-site management of the build

All this and more, makes hiring extension specialists the obvious answer.


Building a ground floor extension is a wonderful way to add space and personal style to your home. And when done right, can also add incredible value to your property.

But it is no easy feat to achieve. It requires thoughtful planning, detailed designing, and skilful building.

As such, hiring professionals and home extension specialists could be the perfect solution to all your home extension needs. Not only can they provide you with guidance on each aspect of the build, but they can also help ensure that the build complies with building guidelines and regulations to give you a beautifully designed and customised home extension that exceeds all your expectations.

If you are hoping to add space, value, and style to your home through single-storey extensions, contact the experts at Good Design and Build today! We create bespoke designs suited to any budget while adhering to our values of professionalism and transparency, giving you peace of mind while we create the best home extension for you.

Author: Amol

Amol is an architectural designer and has worked on hundreds of residential projects in London since 2008.Having done his M.Arch from the Glasgow School of Arts he gained valuable experience in London working in the construction industry managing high-end residential projects, before founding Good Design and Build in 2015.You will meet him for initial consultation and work closely with him during all stages of your project