Get a Quick Quote today

Fill out the form and give us brief details.
We will get back to you with an indicative SIPs extension cost, so you know what to expect.
Once you have an idea of the price of a SIPs extension, you can then make an informed decision.

Or call the experts today on 0330 166 0877

Maximise Your Space with SIPs

Traditional cavity wall construction typically uses up to 350mm of wall thickness, which can eat into your usable floor space—especially in smaller extensions. In contrast, SIPs (Structural Insulated Panels) use just 147mm of thickness while still exceeding modern insulation and strength standards.

In a 4m x 5m extension, this difference alone can free up around 2m² of additional internal space—enough for extra storage, a larger dining area, or simply a more open feel. With SIPs, you’re not just building faster and stronger, you’re building smarter.

Space gained with SIPs

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Home Extensions

Our extension kits are ideal for creating smart, warm and energy-efficient – extensions

AltTextIntroducing Modular House Extensions

Modular house extensions are a cost-effective solution for homeowners who want to expand their living space. 

Our extension kits are made to measure in our own factory according to the dimensions provided by the customer. They are designed to be erected quickly by a small team.

Our modular home extensions are based on structural insulated panels, SIPs. These panels are made of two structural facing boards sandwiched together with extremely insulating foam. SIPs can be cut into virtually any shape or size with absolute precision to form walls and roofs. 

SIPs extension kits are also an ideal product for garden rooms.
sip cross section

Single Storey

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Double Storey

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Popular Finishes

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    White Render

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    Autumn Leaves Brick

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    Red Flamed Brick

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    Rustic Cream Brick

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    Midnight Render

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    Composite Cladding

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AI generated example

The advantages of modular house extensions built with SIPs

Our modular house extensions are a cost-effective and convenient way for homeowners to add space and value to their property. The process compares favourably with other methods used in the building industry, like brick-and-mortar extensions.

  • Speed of construction

    Much of the construction process takes place off-site as the extension kits are prefabricated in our factory. This reduces the on-site construction time considerably and makes installation much quicker and cheaper than a conventional timber or masonry extension.

  • Cheaper construction with less mess

    Extension kits are subjected to stringent quality control at our factory and delivered on-site with clear assembly instructions. A prefabricated modular home extension project can be built in a few days by a small team, saving money on labour costs. As all the materials are created off-site, there is less mess and disruption for the homeowner.

  • Predictable costs

    The cost of the construction materials, the SIPs, is known upfront, so there is no chance of hidden posts or the project budget running out of control.

  • Lightweight construction

    SIPs are extremely light, making them easy to manoeuvre into tight spaces. Their low weight also means that they do not require the deep foundation that other construction methods need, again saving time and both material and labour costs. 

  • Low heating costs

    Modular extensions are gaining popularity for all of the above reasons, but their high levels of insulation and airtight build are some of the reasons that our customers love them. Modular home extensions made from SIPs keep the house warm while reducing healing costs.

  • Reduced energy costs during manufacturing and delivery

    SIPS structures are environmentally friendly throughout the entire manufacturing, delivery, and assembly process. They are manufactured with sustainable timber from managed forests, and our quality control ensures waste is kept to a bare minimum. The low weight of the panels makes them cheap to transport, reducing energy costs and benefitting the environment. 

  • Flexibility of design

    The SIPS can be cut to any design, and we can offer a range of finishes, including brickslips, render and cladding in a range of colours.

  • Superior strength

    Our SIPs panels may be light, but they are also super strong, and SIPs constructions are three times stronger than timber constructions.
Foundation Requirements
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The extension will need to be installed on a concrete base. It may be possible to reuse the base of a previous building like a shed, garage or other garden building.
The Construction Process
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The construction of the SIPS panels means that although they are extremely strong, they are also light and easy to lift and handle, even in the tightest space. Our extension kits can be assembled in less time than a traditional building and by smaller teams, saving on time and labour costs.

Our extension kits are used by building professionals, but competent home builders with some relevant experience and the correct tools for the job also find assembly easy due to the simplicity of the structure and the clear instructions provided.

Customers who find assembling their home extension difficult can call upon our Build Assist service for professional advice.
Environmental sustainability
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Our extension kitzs are an environmentally sustainable choice for a variety of reasons.

• The wood used to construct the panels is sourced from forests managed by the Forest Stewardship Council.
• Our factory production methods use less energy and raw materials than producing the timber and brick used in other types of build.
• The low weight of the panels means that transportation requires less energy.
Insulation and energy efficiency
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One of the big advantages of SIP’s layered construction is the wall thickness and the thermal efficiency of the foam insulation.

The extension kits offer a variety of insulation widths. Customers can choose between 97 mm, 122mm, 147mm, or 172mm. Depending on the wall thickness used, the heating energy required to keep the garden room snug in all seasons can be reduced by as much as 60%.
sip cross section

Get a Quick Quote today

Fill out the form and give us brief details.
We will get back to you with an indicative SIPs extension cost, so you know what to expect.
Once you have an idea of the price of a SIPs extension, you can then make an informed decision.

Or call the experts today on 0330 166 0877

"Build it faster, stronger, warmer and smarter"

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