
UK SIP Panel Specialists
UK SIP panels for faster, warmer builds.
SIP panels and kits for garden rooms, extensions and self-builds, with delivery quoted before checkout.
Structural insulated panels with Celotex (Sopratherm) or IKO Enertherm cores and Sterling OSB3 for airtight, energy-efficient spaces—from garden rooms to extensions and full self-builds.
Build online if you know your sizes, or send drawings if you want us to check the route first.
Products at a glance
Shop the route that matches your build.
SIP Panels (Celotex)
Celotex / SopremaTherm core + Sterling OSB3.
SIP Panels (IKO)
IKO Enertherm core + Sterling OSB3.
Splines & Components
PIR splines, fixings, and details to maintain U-values.
Timber & OSB
C16/C24 timber stock for frames, lintels, and structural use.
Kits
Choose your kit type and footprint for fast, labelled installs.
Garden Rooms
Kit options for fast, airtight builds with a clean finish.
Thickness guide
Not sure which SIP panel to choose?
122mm
Garden rooms
A practical starting point for non-habitable outbuildings, studios and garden rooms.
172mm
Extensions
Usually the safer default for habitable spaces, annexes and Building Control routes.
222mm
High performance
Used where lower U-values or stronger roof performance are part of the brief.
Choose your route
Get to the right price faster.
Start with the option that best matches what you have now. We keep stock product orders, bespoke kits, and advice requests separate so nothing gets priced on the wrong assumptions.
I know my sizes
Build a SIP kit, select the options you need, and request a live delivery quote before checkout.
I have drawings or sketches
Send the files over and we will price the SIP package, lead time, and any clear assumptions.
I need advice first
Speak to the team before you order so we can point you to the right panel thickness and route.
UK workshop support
Panel schedules, product advice and project support
5-10 day delivery*
Stock SIP products on UK mainland orders
UKCA / FPC
Factory production control and panel records
Install partner
Nationwide installation options through Red Rose
Featured products
SIP panels, splines, and ready-to-build kits.

IKO Enertherm
222mm SIP Panel with IKO Enertherm Core
From £336.62 inc VAT
4 options available
5-10 working days*

ULTRASIPS
222mm SIP Panel with Celotex Core
From £255.40 inc VAT
4 options available
5-10 working days*

UltraSIPS
Full House SIP Builds
Request a custom quote
Discuss your build

UltraSIPS
SIP Extension Shells
Request a custom quote
Discuss your build

UltraSIPS
SIP Pods
Request a custom quote
Discuss your build

UltraSIPS
Holiday Home SIP Shells
Request a custom quote
Discuss your build

UltraSIPS
Tiny Home SIP Shells
Request a custom quote
Discuss your build

UltraSIPs
Extra Large Garden Room Technical Drawing
£540.01 inc VAT
Digital delivery
Popular project routes
Examples customers usually ask us to price
Garden office shell
3m x 4m or 4m x 5m SIP kit
A popular route for home offices, gyms and studios where speed, warmth and a clean install matter.
SIP extension package
Walls, roof and openings from drawings
Send plans and we can price the SIP shell, confirm assumptions and separate exclusions clearly.
Golf simulator room
Higher ceiling and roof options
Useful where one area needs more height, larger openings or a different internal layout.
Tiny home or annexe
Budget quote first, drawings next
For habitable projects we normally start from 172mm SIPs and flag Building Control considerations.
After checkout
What happens after you order?
Customers stay interested when the next step is obvious. This is the normal route for custom SIP kit orders.
Order received
We confirm the specification, contact details and any delivery or installation notes.
Documents signed
Production documents and tolerances are accepted before manufacturing starts.
Panel schedule issued
Custom builds are checked, labelled and scheduled so site teams know what each panel is.
Manufacture and packing
Panels are manufactured, checked and packed with the agreed timber, membrane and accessories.
Delivery arranged
Delivery is booked from the quoted vehicle fit. Customers need suitable offloading unless agreed.
How we work
Design → Manufacture → Delivery
We pair engineered SIP panels with clear drawings, predictable lead times, and full support through installation.
Share your drawings
Upload rough sketches or CAD files for a same-day review.
We cost + design
Transparent pricing with engineered drawings ready to build.
Manufacture in the UK
Manufactured SIP panels with labelled components and panel schedules.
Deliver & support
We ship nationwide and stay close through installation.
U-values down to
0.106 W/m²K
142–222mm SIP panels
Faster builds
Up to 50% quicker
Versus traditional timber frames
Engineered drawings
We supply labelled panels, splines, and connection details so on-site crews can assemble without guesswork.
Bring your vision to life
From first sketch to finished build
We partner with designers, builders, and self-builders on every type of SIP project. Share your drawings and we'll engineer, manufacture, and deliver a labelled kit with clear install details.
Self-builds & extensions
Tight U-values, labelled kits, and drawings that keep inspectors happy.
Garden rooms
Standard and bespoke footprints with splines, fixings, and trims ready to install.
Commercial & education
Scaleable SIP solutions for classrooms, pavilions, and modular builds.
What to expect
- • Engineered drawings and labelled panels
- • U-value calcs and Part L compliance support
- • Stock SIP products typically dispatch in 5-10 working days
- • Custom builds and bespoke kits are supplied with a separate lead time
- • WhatsApp/phone support during install
Need a custom footprint?
Send your sketch or DWG and we'll price the SIP package and confirm any custom cutting where agreed.


Performance
Calculate your U-value
Compare OSB thickness and Celotex cores in seconds. Validate compliance before you order.
• BS EN ISO 6946 methodology
• Walls, pitched roofs, and flat roofs
• Shows compliance with Part L 2021
Proof
What builders say
Kevin E
Sarfraz
Garden Room
Barrab
Garden Room
Ready to build with UltraSIPs?
Send your drawings or configure a kit to get pricing and timelines.