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Expand Your Living Space with Fully-Insulated SIP Panel Extensions for Your Home

A faster, cheaper and more innovative way to build your home extension - so you can just enjoy the extra space.

SIP extensions provide a more affordable solution when you need more space in your home

Build your home extension up to 3x faster than traditional construction methods – we can even install them for you

Looking for a cost-effective, smarter way to build your home extension?  Along with their other uses, SIP panels are ideally suited for home extensions to existing builds – as well as standalone garden buildings.

Fully-insulated SIPs panels are incredibly versatile, and can cater for single storey or two storey extensions, or even replacement roofs and extra building storeys.

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Why SIP Panels are Ideal for Extensions in 2026 

In recent years, UK building regulations and energy standards have placed increasing emphasis on energy efficiency, sustainability and reduced carbon emissions. Homeowners and developers now prioritise construction methods that deliver:

  • Superior thermal performance 
  • Improved airtightness 
  • Reduced on-site waste 
  • Faster build times 

SIP Panels (Structural Insulated Panels) meet these goals exceptionally well, making them a very strong choice for home extensions today. This modern context is especially important for meeting current energy targets, managing build programmes and enhancing long-term comfort and value. 

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What Makes SIPs a Strong Choice for Extensions?

Here we’ve listed some of the main advantages when using our high-performance SIPs polystyrene panels for your project:

  • Up to 3x faster than traditional methods - erect a typical house within a week
  • Reduced U-Values as low as 0.10 W/m2K - leading to increased space with a thinner wall
  • 90% less wastage on site (as our panels are manufactured off-site)
  • Zero reliance on weather conditions - for minimal disruption to the critical path
  • Lightweight - ideal for sites in city centres with access restrictions
  • Easier installation - with reduced drilling and crane use on site
  • Huge savings on labour - with reduced number of trades and supervision on site
  • 60% less timber than traditional build methods
  • Increased usable roof space - fully-insulated roofs without trusses
  • Build up to 4 storeys with SIPs (or five with blockwork or steel first storey)
  • 7x stronger than timber frame - and 3x stronger than brick and block
  • Excellent insulation values for increased resale value
  • Airtight, with reduced cold bridging
  • Lower annual energy costs
  • Does not degrade or deteriorate over time
  • Naturally more eco-friendly than other build types
Architects drawing of a SIPS Panel Extension

What are the Benefits of SIP Extensions for Your Home?

Our structural insulated panels are ideal for home extensions for a number of reasons:

Firstly, SIP panels are prefabricated off site in factory conditions, meaning they are not subject to site weather conditions; this also makes them stronger.  They can be delivered pre-cut in manageable sized panels making them easy to construct on tight sites, or sites with limited access.

SIPs are very speedy to erect; a home extension can be walled and roofed quicker than with other forms of construction, making it not only cheaper, but easier and quicker to knock-through.

And finally, SIP panels are insulated, so there’s no need for cavity or internal insulation when building your SIP extension.  This makes things far simpler when constructing your home’s new extension.

Our high-strength, high-performance SIP panels are:

  • Non-toxic
  • Low carbon footprint
  • Made with 100% recyclable EPS
  • Water resistant
  • Fire rated
  • Breathable
  • Mould resistant
  • Extremely Strong

Here's what some of our customers are saying:

"We are very pleased with the quality of product and services Sips Eco Panels offer and the entire build process has both matched and exceeded our expectations."

Richard Weller, Stratford Upon Avon

How SIP Extensions Work

SIPs are pre-manufactured panels combining high-performance insulation and structural support. Installed quickly and accurately, these panels help extend your home while improving energy performance and minimising disruption on site. 

Why Choose SIPs Eco Panels for your Home Extension?

As a family-run business with over 35 years’ experience in construction, we have a team of highly-experienced professionals who are on-hand to guide homeowners through every stage of their SIP panel extensions.

When you contact us for a quote, you can upload your drawings, and details of your existing property.  Our team can even install your SIP panels for you on the day, taking on the risk of your home extension project.

Once you give us the go-ahead, you’ll be assigned a dedicated production manager to follow your project all the way through to completion, with on-site and off-site support available.

The SIPS extension being built

Product Information

  • Thermal Bridging
  • Air tightness
  • Fire Performance
  • Panel Sizes

  • Our award-winning system uses Sip joining splines to connect the panels, providing continuous insulation, not interrupted by repeated stud work, giving high levels of air tightness minimising any heat loss through thermal bridging.

  • Sips Eco Panels comprise two sheets of OSB3 sandwiching a core of high-performance rigid EPS insulation. Our innovative insulated Sips spline system joins the panels together creating an airtight structure which can assist to achieve Passivhaus performance standards.

    Standard Sips Eco kits have High Levels of air tightness (typically 2-4acph).

  • Sips Eco Panels load bearing walls have achieved a 75 minute fire rating (BS476 Pt 21). While non-load bearing walls can achieve up to a 90 minute fire rating (BS476 Pt 22).

  • All our Sips Eco Panels have a standard width of 1200mm, with standard lengths of 2400, 2700 and 5100mm.
    Panel thickness range – 119mm, 144mm, 169mm, 194mm & 219mm
    *Non standard sizes can be cut from the standard panels

Thermal Bridging

Air tightness

Fire Performance

Panel Sizes

Looking to build a SIP extension for your home? Get in touch and request your free quote today

One of our experienced SIP specialists will be in touch – usually within one business day – to talk you through your options.

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