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
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
Use Our Calculator!
House Kitz
The Last Home You’ll Ever Need
Create your forever home with House Kitz.
House Kitz from Extension Kitz brings together the proven strength and performance of our SIP panel system with the freedom to create a truly bespoke living space — built around your life, your needs, and your future.
Using the same innovative, energy-efficient SIP technology trusted across our entire range, this is more than just a house — it’s a smart, sustainable, fully tailored home designed to grow with you. Whether you're planning your dream family space, a peaceful rural retreat, or a future-ready downsizer, we make it possible.
Using the same innovative, energy-efficient SIP technology trusted across our entire range, this is more than just a house — it’s a smart, sustainable, fully tailored home designed to grow with you. Whether you're planning your dream family space, a peaceful rural retreat, or a future-ready downsizer, we make it possible.
Why choose House Kitz?
Built using our advanced SIP panels for unbeatable thermal efficiency
Completely bespoke layouts, features and finishes
Panels are custom-made in our UK facility and fully dry-fitted for quality assurance.
Dry-constructed and pre-assembled in our UK factory
Quick, clean assembly with minimal disruption to your home life.
Faster build times, fewer delays, and complete peace of mind
Choose from a range of internal and external finishes to complete your dream space.
Future-proof designs that adapt as your lifestyle evolves
Choose from a range of internal and external finishes to complete your dream space.
The advantages of bespoke homes 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.
"Build it faster, stronger, warmer and smarter"
HEAD OFFICE
Cemetery Works, Cemetery Road, Radcliffe, Greater Manchester, M26 4FT
sales@extensionkitz.co.uk
0330 166 0877EXTENSION KITZ
We are an established, family run, innovative manufacturer and supplier of Structurally Insulated Panels (SIPs) for home extensions, annexes, pods, garden rooms, and modular educational buildings.
Copyright © 2025 Extension Kitz | Site by elate global