SIP technology

A SIP panel is a structural element: the OSB skins work together with the rigid core. Load-bearing capacity is calculated for the specific house, though (vertical loads, wind, snow, floors, openings and the panel connections), rather than given by a single figure valid for any panel. That calculation is part of the permit project: the structural engineer does it for the specific house and plot.

Mould and condensation do not come from the material but from moisture with nowhere to go. What is specific to a SIP house is that a correctly assembled envelope is very airtight, so the air exchange has to be organised in the design rather than left to gaps. We seal the panel joints and treat ventilation, heat recovery included, as part of the services design.

The fair comparison is not one material but the whole wall. Ceramic brick is a non-combustible A1 material, while timber-based boards and polymer insulation sit in other reaction-to-fire classes, and we do not claim SIP is inherently safer. Fire resistance comes from the finished construction: the panel is closed on both faces by OSB and the finish layers, the wiring runs in protected channels, and the position of heating equipment and the flues are designed separately.

Assembled correctly and protected from moisture, a SIP house lasts 50 years and more. There is one underlying condition: the timber-based elements of the panel have to stay dry, so the roof connections, the sealed joints, the window fitting, the plinth waterproofing and the service penetrations matter more than any single material. Where our teams assemble the house, in Romania, we give a 10-year warranty on the structural integrity of the building; where a local contractor assembles it, the warranty is theirs.

Almost the whole thickness of the panel works as insulation, so a good thermal resistance comes at a thin wall. The fair comparison is between complete walls rather than between materials, though: modern masonry reaches the same figures with a ceramic block plus a layer of insulation, the wall simply ends up thicker. Summer comfort is not decided by the walls alone: orientation, glazed area, shading and ventilation decide it.

The panels are made in the factory and only assembled on site, with no wet processes like concrete or plaster, so building can go on all year. The time saving is on site: the structure goes up in 1–2 weeks and the roof in about a week, and a turnkey house is ready in up to 6 months from the deposit, permit time not included. On money the honest answer is that the saving comes from fewer manual operations on site and from the lower weight of the house, but it does not follow that any SIP house is cheaper than any block or timber-frame house: the architecture, the plot and the finishing level move that picture.

The honest answer: airborne sound is stopped by mass, and a SIP panel is light, so on its own it is not an ideal acoustic solution. The sound insulation you need comes from the whole construction: framed partitions with mineral wool, added lining layers, acoustic decoupling and a properly built floor assembly. It is designed in, not added after moving day.

All materials are certified: the polystyrene is inert and doesn't release harmful substances inside a closed panel, and the OSB's formaldehyde level stays within European norms (E0–E1).