Extension Kit Features

Building Control made easy

Your Single Storey Extension has been independently tested and certified to gain System Approval Certification from an approved building inspecto. These tests involve detailed analysis and verification of the roof system from independently sourced structural calculations, along with further assessment checks on thermal performance and condensation risk analysis.


The following calculations have been carried out by an independent Insulation Specification Specialist to achieve a 0.15 Wm2K for Pitched Roofs, 0.16 Wm2K for Walls and 0.13 Wm2K for Flat Roofs.

The calculations also undertook a Condensation Risk Analysis and further assessments that calculate the predicted dewpoint temperature. The results show there is no risk of condensation / moisture build up within the roof or walls. These results are paramount to ensuring no gradual degradation of the construction materials or chances of mould growth.


When making an investment to your home, it is vitally important you can trust the product you are purchasing. With a Single Storey Extension you will receive a tried and tested system that is fully approved.
  • 10 Year Manufacturing Warranty
  • 40 Year Tile Manufacturers Warranty

Pitched Roof Designs Options

Thanks to our unique pod system and innovative design, the Single Storey can be adapted to all roof styles. Our timber frame allows us to create completely bespoke designs suited to the space you have available for your Extension.

Vaulted Ceilings
Thanks to our structurally engineered steel corner braces which are completely concealed, you are able to have a clean vaulted ceiling without the need of Truss – es, Tie bars / Tie wires on any pitched roof up to 5 x 5m.

Complete Kit One Supplier

Assembly drawings are supplied with all Extension Kits


A simple but effective shape made up of three sides sloping towards ridge.

Double Edwardian with box gutter

Double sided Edwardian with aluminium box gutter.


A simple, mono pitched roof offers clean lines. Perfect for adding large opening vents.

Hipped lean-to

Same shape as a lean-to with the addition of two hips creating two extra sloping sides.


A contemporary look with the option of a glass gable frame to front to maximise natural light.

Stylish Roof Exteriors

Slate options manufactured from recyclable blend of limestone and polypropylene mimic the appearance of genuine slate with textured surface and riven edges. Shingle options are manufactured from galvanised steel sheet with a stone-coated finish. These are a practical, economical and sustainable tile option for your roof.
  • 40 Year Tile Manufacturers Warranty

Gutter Colour Options

Fascia Colour Options

Slate Tiles

Shingle Tiles

What is a WarmerBase?

A durable steel system, all delivered in kit form to ensure a smooth installation with no large amounts of concrete or building materials needed, unlike traditional methods. The steel frame is placed on concrete pads and is fully insulated for maximum thermal efficiency. The Durabase System arrives in sections for easy handling, so even the narrowest sites with difficult access are not a problem. You’re also welcome to come visit our stunning 6,000 sq ft showroom in Somerset to see our range of DIY home extensions up close and personal.

Building Control Approved
Your Warmer Base has been tested and certified by an approved building inspector

Let there be light

With unrivalled looks and thermal performance, the Flat Roof System combined with a glass lantern will bring stylish ambience to your home whilst maximising natural light and provide you with a bright and airy living space. Our timber pod system, filled with 125mm of honeycomb insulation offers exceptional thermal performance, covered externally with Firestone EPDM rubber for extreme durability and complemented with a contemporary external soffit detail, perfect for adding spot lights.

  • 40 Year Tile Manufacturers Warranty

Stylish External Cladding

Easy to install

All Freefoam cladding products are easy to fit. Both the standard PVC-U and Aluminium range of fitting trims ensure every installation is straightforward, designed to create a neat and professional finish.

Very low maintenance
PVC is a very stable material. Cladding products made from PVC do not require repainting or regular maintenance. A simple wipe-down with a damp cloth is all that’s required to keep Freefoam cladding products looking their best. This offers a major long-term advantage over wood cladding saving time and money
Freefoam cladding can be used on all types of exteriors including brick, masonry and concrete. Suitable for a wide variety of projects and situations, offering an attractive facade for both traditional and contemporary projects
Cut heating costs with exterior cladding

With heating costs always a concern, fitting exterior wall cladding can provide the ideal solution to insulate your home. When installed with generic insulation materials, The Building Research Establishment’s (BRE) ‘Green Guide to Specification’ has given PVC cladding an A+ rating.

  • 10 Year guarantee provided on all Cladding.

Over 40 brick choices!

Contact us today to start your single-storey extension.

Autumn Leaves
Red Dragwire
Rustic Cream
Smooth Anthracite

Your Questions Answered

Choosing to build your own extension can feel overwhelming, especially when it comes to buying your DIY home extension kit. It is natural to have questions about what you are buying and how it works, so below, we have answered some of the questions we get asked the most.

If you can’t find the answer to your question, don’t hesitate to contact our expert team online or by calling 01371 820580. We are always happy to discuss our products and help you figure out what you need for your home extension project.

Will I need planning permission for a DIY home extension?
When building a do-it-yourself home extension, typically, you won't need planning permission. This is because for most extensions, permitted development rights will apply. However, there may be some exceptions, so it's a good idea to speak with your local authorities before starting your extension. They can tell you whether you will need planning approval and, if so, can help you with the application process.
Are your DIY home extension kits building controls approved?
Yes! Another great reason for using one of our DIY home extensions is that they have received building control’s pre-approval from Stroma. Stroma are a nationally accredited building control approvals agency that provides thorough testing of our kits. The testing includes detailed analysis and verification of the roof system using independently sourced structural calculations, so you can rest assured that your kit is fit for purpose.
How much do your DIY home extension kits cost?

A significant benefit of DIY home extensions is their affordability; our kits, with any type of roof, start at just £1,200 per square metre, thousands less than a traditional extension price.

The precise cost of a Trade Price Warmer Living extension kit can vary greatly because each one is tailored to your house and requirements. A larger, more intricate design will cost more than a simpler one, and vice versa.

Do I need to be an experienced builder to install your DIY extension kits?
Not at all. Our kits are designed to be easy for a beginner to build themselves. Your kit will come with step-by-step instructions detailing what you need to do and when. Plus, the DIY kit will come with everything you need to construct the extension yourself, so you don’t need to worry about buying any extra materials for your project.
Which roof styles can my DIY extension have?

You can choose from six different roofs to go on your home extension. The options are: Lean-to, Lean-to side hipped, Edwardian, Edwardian double hipped, Gable-end, Flat roof.

No matter which roof you pick, you will benefit from Warmer Roof technology, which uses an innovative honeycomb design to provide the highest level of insulation of any roof on the market, keeping the warmth in the room during the winter and out during the summer.

Can I pay for my DIY extension on finance?

Absolutely. We are now able to advise you on a range of financing solutions, including our Buy Now, Pay Later plan, as we have authorisation from the FCA. Our staff are always available to help you navigate the various financing options so you can select the one that best suits your requirements and financial situation.

Get in touch with us for an initial consultation, where we can discuss our finance options in more detail.

Why choose a DIY extension over a traditional extension?
There are a few reasons why homeowners choose our DIY home extensions over a traditional extension: Save thousands in installation fees. Benefit from greater design flexibility. Complete the project quicker. Our extension kits have a longer warranty. Feel a sense of satisfaction from doing it yourself.
Will my DIY extension be covered under warranty?
Of course. All of our extensions are covered by a 10-year product guarantee that’s comparable to even the NHBC new build warranties. Every aspect of your extension will be covered, from materials to the construction itself, meaning you can have peace of mind knowing that your investment is protected for years to come.