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House Extensions

Building Services / Extensions

We are experts in creating

spectacular spaces, which

you can call home.

House Extensions Cardiff & South Wales

We undertake all extension projects across Cardiff & surrounding areas of South Wales

A home extension will provide a brand new usable space.

Extensions add up to 20% value to a property. (The Guardian)

Our expertise will ensure your home extension meets every need and is of the very highest quality.

Here's what our home extension customers have to say...

Our services cover the entire range of home extensions

-    Single, Double or Multi-Storey Extension

-    Side Return Extension

-    Rear Extension

-    Wrap Around House Extension

-    Conservatory / Sunroom

-    Porch

Choose from a range of building materials

With a range of building materials to choose from, it's easy to create the home extension of your dreams 

Brick Wall


Wooden Planks


Glass Panes


Image by Juhani Pelli

Block & Render

Choosing to extend your home can help you achieve many things...

Here are several ways a home extension can positively impact your life:

Create more space to meet your needs, eliminating the need to move to a bigger, more expensive house.

Take total control of the layout and ensure its bespoke design meets your every want and need.

Achieve your dream of having a kitchen diner, extra lounge area, home gym or home office space.

Provide your children with the safe entertainment space they crave to have fun in.

Accommodate an elderly relative by offering them to live with or visit you in a modern granny annex.

Feel proud of your home and enjoy utilising it effectively with visiting friends and family.

Rear extension to a property in Cardiff, South Wales
Side extension to a property in Cardiff, South Wales
Rear extension to a property in Cardiff, South Wales
Rear extension to a property in Cardiff, South Wales

It's simple, we create space.


Free quotation. Expert advice. Total piece of mind.

Why Choose Us For Your House Extension?

We go above and beyond to ensure we offer the best experience along with top quality results. We have a vast back catalogue of home extension projects that we have completed, and as no two builds are the same we have gained a wealth of experience that we can carry forward into each new build we create.

We make sure you are kept fully up to date with the progress of your home extension, so we work closely with you every step of the way. Our expert team of builders are always on hand to discuss any questions or ideas you may like to explore.

We listen to your ideas and communicate our own so that we can bring your plans and drawings to life, all while ensuring your extension build complies with all building regulations.

We utilise highly skilled tradesmen who will issue you with all relevant paperwork such as Gas Safe and NIC certificates.

We have expert knowledge in understanding the structure of a wide range of properties, from period through to modern. This allows us to create large open spaces that gain maximum natural light and can be utilised as you see fit, without compromising the property.

We guarantee all of our work after completion of the build, giving you complete peace of mind in the knowledge of knowing that our structures are designed and built to last.

Are you ready to discuss your house extension project?

Contact us today with details of your requirements to book your free no obligation quotation.

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House Extension Enquiry

House Extension FAQs

House Extension FAQs

What can I expect from your design and build house extensions?

Our design and build house extensions are designed to provide you with everything you need from an additional space for your property. A one stop shop, if you will.


We will ensure everything is taken care of, from plans and design right through to completion, leaving you with a bespoke house extension that is built to the highest quality and adheres to all local building rules and regulations.


Our team will plan, design and build your new home extension to your exact requirements. We will be on hand to offer our expertise throughout the project, will keep you updated during its progress and will do all that we can to make sure the entire building process is as stress-free as possible for you.

Can all properties be extended?

Most properties can be extended, though it does depend on the amount of available space. Factors need to be considered, such as the available space in the garden or along the side of the property, the area, the council regulations and other things like this. One of the biggest factors is the space you have available outside the property as there are different regulations with regards to building a home extension.


Our site surveyor will be able to tell you during initial discussions the options that are available to you and what sort of extension projects you can consider.

How much does a house extension cost?

Because each house extension project is bespoke and different from the next, it's difficult to provide a ball park figure for each project. The size, specifications, materials and obstacles are just a few things we need to consider.


Fortunately, we do offer a free no obligation quotation where we will visit the property and discuss things in detail so that we can work out an accurate cost for you.

What different types of house extensions are there?

There are a wide range of different types of house extensions available, and the extension or choice of extensions that are best suited to you will depend on the type of property you have and the space that is available.


We can discuss the extension types in more detail during our initial discussions at your property, outlining the advantages and disadvantages of each one, but the most popular types of extension are:


  • Single storey side or rear extensions

  • Double or multiple storey extensions

  • Garage or kitchen extensions

  • Outbuilding, conservatories, porches and orangeries


Extensions are also a popular addition that people choose to run alongside a conversion project, or to extend an existing conversion. For example, a new or existing garage or basement conversion can include extension plans where possible.

Do I need planning permission to build a house extension?

In most cases the building of a house extension requires no planning permission because they come under permitted development rules. This means there are no issues with building your extension provided local building rules and regulations are followed.


This doesn't mean that you can simply build whatever you like, as plans still need to be submitted, structural calculations need to be made and you will still need approval from local building control.


If your property is a listed building, located in a conservation area or in an area where permitted development is not allowed then you must receive planning permission from your council before undergoing a home extension project.


Do I need to get permission from my neighbours?

If you have a party wall connecting your property, then you will need inform your neighbours about the home extension plans you're choosing to undergo. You don't need permission from them as such, but you do need to tell them. If they have a problem with the proposed extension plans then you'll need to get a party wall surveyor involved.


If it came to this, the party wall surveyor would then issue party wall notices on your behalf as well as scheduling a time to inspect the connecting wall. They will take photographs and produce a party wall award that will outline the works that can be carried out. This is a very straight forward process and should not be confused with planning permission, as there is no room for refusal in this.

Do you only carry out house extensions in Cardiff?

We carry out home extensions in all shapes and sizes, and for a wide range of purposes right across Cardiff as well as the surrounding areas of South Wales.


Do you have the relevant accreditation?

Yes, RGB Construction are members of the Federation of Master Builders (FMB).


Will my house extension come with a guarantee?

Yes, as with all our completed building projects, your house extension will come complete with a guarantee.

What can I expect from your design and build house extensions?
Can all properties be extended?
How much does a house extension cost?
What different types of house extensions are there?
Do I need planning permission to build a house extension?
Do I need to get permission from my neighbours?
Do you only carry out house extensions in Cardiff?
Do you have the relevant accreditation?
Will my house extension come with a guarantee?

We cover Cardiff and surrounding areas of South Wales.

If you're looking for a team of expert builders in Cardiff to design and build your dream home extension, then don't hesitate to get in touch with us today.

A map of the area in Cardiff and South Wales that RGB Construction undertake building services

As well as building high quality extensions, we also enjoy writing about all things building and construction.

Our news page is where we keep our latest news, tips and related building information.

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