Hargrave SIP Build

A faster, smarter way to build
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High-performance extensions, annexes, garden rooms and new builds using Structural Insulated Panels (SIPs) - designed for faster build times, better thermal performance and a more efficient route to completion.

Build faster. Live sooner.

Hargrave SIP Build offers a modern alternative to traditional construction. Using Structural Insulated Panels (SIPs), we deliver high-quality structures that are faster to install, highly insulated, energy efficient and built to last.

Whether you're planning a garden room, home extension, annexe or full new build, SIPs offer a smarter way to build, with less time on site, less disruption and faster progress from day one.

Why choose SIPs?

• Faster build times
• Excellent thermal performance
• Less on-site disruption
• Highly durable construction
• Low-maintenance, long-life structures
• Manufactured in the UK
• A more efficient route from build to finish
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What can we build?

garden rooms

Garden rooms

home office

Home offices

annex

Annexes

studio

Studios

new build

New build homes

extensions

Extensions

If you can design it, SIPs can build it.

Built for speed, built to last

Our SIP structures can be made weathertight in as little as 5 days, allowing internal works to begin far sooner than traditional build methods. That means:

• Faster progress on site
• Reduced programme time
• Earlier use of your new space
• Less disruption to your home

A faster build should never mean a compromise in quality. With Hargrave SIP Build, it doesn’t.

Limited 2026 project availability

We’re currently opening a limited number of Hargrave SIP Build projects for 2026 across Kent, the South East and London.

If you’re considering a SIP build and would like to be one of the first projects in our launch programme, register your interest below.

Join the waitlist

Be one of the first to hear more about Hargrave SIP Build and secure early access to our 2026 project slots.