Situated seven degrees west of the Greenwich Meridian, and exposed to some of the harshest weather conditions anywhere in the British Isles, the Hebrides present a challenging location for building projects, prompting a recently-established building company to adopt offsite construction technologies which make full use of the technical and environmental benefits of West Fraser’s SterlingOSB Zero.


70-22’ Systems was established in 2022 by three business partners whose experience encapsulates architecture, education and manufacturing amongst other skills, and who decided to develop their own highly-insulated, modular timber building system.  Growing organically by providing bespoke packages to clients of parent business, Fraser Architecture, 70-22’ has already delivered properties on the Outer Hebrides; and has more than half a dozen schemes of different sizes in the pipeline for the coming year.

The trademarked system has been designed specifically to avoid the need for craneage, due to the inaccessibility of many sites, while the cellular component modules take the form of wall blocks, lintels and beams to span larger openings.  The SterlingOSB Zero is CNC machined and assembled in the workshop before being filled with Warmcel recycled paper insulation.

Significantly, the 70-22’ Systems design personnel were determined from the outset to utilise the West Fraser board because of its formaldehyde free formulation and the fact the material is manufactured in the North of Scotland, using mainly locally sourced softwood from well managed forests.

70-22’ Systems’ co-founder and Commercial Director, Alex Durie, commented:

“We use West Fraser’s SterlingOSB Zero to construct our ecological building components, that are prefabricated in our workshop utilising CNC technology to achieve 0.1mm tolerances for each beam and block.  It is the ideal material to use as the shell for our components, which are then filled with recycled insulation to achieve a building system that can achieve market leading thermal performance, with a U-value of 0.1 W/m²k, and excellent air-tightness, while maintaining a breathable floor, wall and roof construction. The added bonus of being formaldehyde-free, OSB enables us to build ecologically, utilising timber grown and processed in Scotland as we aim to limit the travel miles in each of our builds. The OSB produced by West Fraser has performed very well in our structural testing, with our system proving to be 1.6 times stronger than a traditional timber frame – and as our system arrives on site as a component that is pre-fabricated, pre-insulated and designed for manual handling, it is much quicker to assemble.”

Not only do all of the 70-22’ Systems structures exceed the thermal requirements of Section 6 to the Building Standards, Scotland, but can also be delivered as a Passivhaus compliant solution where the client or planning consent demand it.  In the medium to long term, the business is building a pattern book of standard house types and has plans to establish a pilot plant on the mainland.  The company will also be showcasing its system at the Self-Build and Renovation exhibition in Aviemore this autumn.

SterlingOSB Zero is available in a range of sizes and thicknesses up to 22mm as well as a T&G version ideal for flooring and decking applications.  The high performance panel product, free of added formaldehyde, has also earned BBA approval and meets the requirements of NHBC Technical.

As is always the case, West Fraser’s experienced technical team is available

to aid with product specification

CLICK HERE for downloadable data sheets