Skip navigation

Can we Help?

If you have any questions, just let us know. Fill in your details below and we'll get back to you.

Contact Form

An energy efficient all-weather solution

Our Annexes are outstandingly thermal efficiency, outperforming many modern homes. We utilise state-of-the-art materials ensuring our buildings require minimal energy so you can maintain your home at a perfect ambient temperature winter and summer, without burning a hole in your pocket.

Structural Insulated Panels (SIPS)

SIPs are a modern composite building material, combining several components of conventional building such as stud and joists, insulation, vapour barrier and air barrier. SIPs are formed from two layers of OSB (oriented strand board) between which is rigid core of expanded polyurethane foam. We screw the panels together with long, high tensile self-tapping screws and use expanding adhesive foam to ensure 100% air tightness.

The floors walls and ceilings of our buildings are constructed using SIPs. Many years' in this industry have enabled us to test and refine our materials ensuring only the very best, most durable and thermally efficient SIPs are used.

Why do we use SIPs?

A well-built SIPs structure will have a tighter build envelope with higher insulating properties than conventional builds, meaning fewer drafts and reduced operating costs.

Construction time is also reduced compared to a traditional methods because SIPs work as the structural framing, insulation and exterior sheathing and come pre-cut to your bespoke design, from the factory. They afford great design versatility and require less time and fewer tradesmen to install, saving you money.

The total life-cycle cost of your building will usually be cheaper, achieving up to 40% life-time savings.

Building Regulations and Energy Efficiency

Under the latest revisions to Part L (England & Wales) of Building Regulations, a minimum standard U-value is required for newly constructed building. Annexe Spaces buildings are designed and manufactured to exceed the thermal efficiencies required under this new legislation.

What is a U-value?

A U-value is a measure of thermal efficiency. It is; 'a measure of air-to-air heat transmission (loss or gain) due to thermal conductance and the difference in indoor and outdoor temperatures, in relation to an area of material, expressed as w/m2k (watts per square metre Kelvin)'

As the U-value decreases, so does the amount of heat transferred through the material, i.e. the lower the U-value, the better the level of insulation.

Required U-values

To comply with the new Part L (England & Wales) Building Regulations building components must have U-values that are at least equivalent to the following:

• Walls - Building Regulations Minimum = 0.35 Wm2k

• Floor - Building Regulations Minimum = 0.25 Wm2k

• Roof - Building Regulations Minimum = 0.20 Wm2k

The other structural components further enhance the thermal performance of our construction system including; plasterboard, thick timber cladding, laminate floor with underlay and EPDM rubber roofing.