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Home Extensions Made Easy

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Extension Kitz

SIP Panel Extensions

Here at Extension Kitz we manufacture and supply quality single, double storey Home Extensions, Garden Rooms, Annexes and Houses for both the trade and the domestic market.

Our Structural Insulated Panels (SIPs) extension kits offer builders and homeowners a design and supply solution for extending residential properties to the rear, to the side or as a stand-alone extension, quickly, efficiently and cost effectively.

We also create and manufacture extensions with our SIPs for schools.
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Hear from our customers

Create additional space in your home with our SIP extension kits

Constructed under controlled conditions in our 40,000sq ft factory, our SIP extensions are tailor made specific to your individual requirements, delivered to site ready for installation by ourselves or one of our preferred installers.

Whether you want a larger living room, kitchen, or dining room, or you’re planning to add a new downstairs bedroom, playroom, bathroom, study, or annexe, we have the expertise to build your dream extension seamlessly, quickly and tailored exclusively for you.

Manufactured by us, installed by ourselves, or one of our preferred installers.
Your dream home extension can become a reality in a far shorter time than via traditional building methods.

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The SIPs Panel System from Extension Kitz

FASTER INSTALLATION
The SIP building has always been “DRY BUILT” in our factory. The panels are cut and prepped and the external membrane, factory fitted along with the external battens ready to take your preferred finish. This creates a superfast installation saving you time, saving you money.
STRONGER BUILD
The Extension Kitz wall system is robust and has a solid feel compared to other timber frame systems. It is so robust that it is THREE times stronger than a brick wall. When it comes to fitting any internal cupboards etc. they can be fixed straight to the internal wall without additional noggins.
WARMER WALL SYSTEM
The Extension Kitz wall system reaches an amazing 0.15 U-value when finished with brick slips and render. The Polyurethane (PU) core of the SIP panel ensures a super energy efficient walling system.
SMARTER WAY OF BUILDING
Combining the speed on erection, the strength of the EK walling system and its energy efficiency resulting in a truly SMARTER way of building. However, that is not all of it! Compared to traditional build of bricks and mortar, Extension Kitz will give you an increased internal room creating you more space to live in.
living-space-extension-interior-kitchen
SIPs are light yet much stronger than traditional build and can often just rest on existing foundations providing they are approved for this type of building. Most people tend to opt for concrete bases.

In these situations, SIPs can help save money because it reduces the potential costs of substructures, structural steelwork as well as the need for load-bearing internal walls. The SIP walls are slimmer than traditional build so, providing more useable space. And both the roof and walls are more thermally efficient with a U-value of 0.15 being standard.

Foundations need only be a simple concrete base. They are sometimes on existing bases when transforming a conservatory into an extension.

The structure can be up and watertight in just a few days. Once built, SIP Structures are three times stronger than your average brick build, or seven times stronger than timber framed buildings.

Choose from an exterior of brickslips, cladding or render

 
Faster Installation
SIP panels are manufactured in our factory to the exact dimensions of the extension, delivered to site ready for erection.
 
Warmer higher U-value as standard
SIPs are airtight in construction, compact with a U-value of 0.15 as standard.
 
Eco-friendly
much better for the environment.
 
Little disruption on site
Constructed in our factory, so creating less issues on site and less labour is required.
 
Enhanced Structural Performance
The intrinsic construction of SIP panels offers strength and stability which is 3x stronger than traditional build.
sip panel cross section
Structural Insulated Panel cross-section
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Why use Extension Kitz

 
Built in our factory in the UK
Skilled experienced staff fabricating our SIPs system in our 40,000sqft purpose-built factory.
 
Design, Build & Installation
Project managed from design to build, and installation where required.
 
Award winning support
Our technical support team is always at hand should installers have any queries.
 
Innovation
R & D arm to design new products and improve existing offerings.
 
Wide product range
Range of products – SIP panels, Home Extension Kits, Pods, Garden Rooms, Annexes, Modular Educational Buildings, Cinema Rooms. Extension to a building or Stand Alone.
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What are SIPs?

Structural Insulated Panels (SIPs) are a modern, high-performance construction solution that combine structural strength and thermal efficiency in a single system. They use advanced composite panel technology to deliver superior performance in both residential and light commercial builds.

Each SIP consists of a PUR insulating foam core (Polyurethane) sandwiched between two layers of oriented strand board (OSB). The foam chemically bonds the two layers of OSB to create an extremely strong and thermally efficient system. Produced in a controlled factory environment, the panels can be custom-made to suit almost any design. The result is a lightweight, durable building system that offers excellent energy efficiency, rapid installation, and minimal thermal bridging.

SIPs are engineered, load-bearing, timber-based components suitable for walls and roofs. As they are prefabricated offsite and delivered ready for assembly, they offer significant time and cost advantages. This panelised construction method enables the creation of highly airtight, thermally efficient building envelopes, making SIPs an ideal choice for modern construction projects.

SIPs are revolutionising the way you think about extending your home.
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Our Extension Kitz

Find inspiration for your project – browse our gallery of completed work.

How We Do It

Find inspiration for your project – browse our gallery of completed work.

Create additional space in your home with our SIP extension kits

extension kitz brick slips
Stage 6: Installation of Brick Slips is completed and pointed to give the look and feel of a brick build. Your SIP extensions is completed in a fraction of the time taken for a conventional build and with minimum fuss.
extension kitz roof
Stage 5: The roof is completed with your choice of tiles. The installation of the Brick Slips begins. We have a wide range of finishing options to match your home. Glazing and doors are installed.
extension kitz frame
Stage 4: Framework is constructed for windows, doors and roof if it is an aluminium roofing frame. Work begins on installing tiles, wrapping and battens.
extension kitz base plates
Stage 3: Wall plates, base plates, membrane, and starter timbers are installed, followed by the SIP panels and splines. If the roof is a SIP roof this will also be constructed.
extension kitz concrete base
Stage 2: Once the concrete is poured and levelled it is left for approx 72 hours to set depending on the weather. Once set work can begin.
extension kitz base
Stage 1: The ground is dug out to the required depth, damp proof membrane, underfloor insulation and steel mesh are installed ready for concrete pouring.

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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