TEK Building System
High performance structural insulated panels
Graven Hill has established itself as one of the leading communities of self-built and custom homes here in the UK. Located near the town of Bicester, the village has space for up-to 1,900 homes supported with a range of local amenities. When Daniel Frazer purchased a plot of land within the third wave of development, he was committed to creating a distinctive and beautiful home which perfectly met his needs.
"I knew that by using a timber frame construction it would be possible to achieve excellent speed of build, particularly as it can be erected in most weather conditions. Whilst SIPs Panels raised the material costs, they delivered several additional benefits including enhanced airtightness, even faster build speeds and the ability to use the panels to construct the roof.
I eventually chose the TEK Building System after meeting with Point 1 Building Systems. They understood my requirements and provided thorough pre-sales engagement showing how they could deliver some of the more challenging details".
Daniel Frazer, Homeowner
The TEK Building System is formed from rigid insulation panels which are faced with OSB/3. TEK SIPs Panels are pre-cut to each project’s specifications by trained Kingspan TEK Delivery Partners. This offsite construction approach supports a simple and accurate installation, often allowing SIPs homes to be constructed faster than would be possible with traditional methods. Their unique jointing system also ensures excellent insulation continuity throughout the envelope whilst limiting air-leakage.
LOCATIONOxfordshire, UK
ArchitectGreenspace Architects
At the outset, Daniel envisaged that the property would be constructed using timber framing methods before finally settling on SIPs Panels as the primary envelope material.
Greenspace Architects developed the designs for the building, working in close collaboration with Point 1 Building Systems. The outer envelope combines timber and artificial slate cladding in a distinctive modern design which features both flat and pitched roofs. The first floor has been rotated to provide outstanding views whilst making best use of natural light within the internal space.
"The first-floor volume cantilevers in two directions to create a balcony to the front of the house, along with an inset entrance doorway. We try to minimise the use of steel with SIPs projects but in this case it was necessary. The benefit of TEK panels is that they can be used in combination with other structural elements – whether it is steel, glue-lam or masonry. It was also incredibly helpful to have an experienced TEK Delivery Partner to advise on detailing and avoid unnecessary complications".
Geraint Edwards, Greenspace Architects
A couple of areas of low pitch flat roof were also included to complete a full house of complex construction details. 3D modelling via HSBcad made this project possible. The building is built in a virtual model space prior to manufacturing of components. This ensures perfect fit for our clients and approval / acceptance prior to materials arriving on site.
Once the design was agreed, they precisely manufactured the SIPs panels before delivering them to site to a carefully scheduled programme. This offsite construction approach supported a rapid build programme and allowed materials to be stored within the perimeter of the site, and without encroaching into neighbouring plots.
In addition to the steel structural elements, the final package combines 142 mm TEK panels with a 25 mm layer of Thermawall TW55 and Thermapitch TP10 which was fitted throughout the envelope internally. This design allowed the demanding fabric requirements of the Graven Hill Plot Passport, including wall and roof U-values of 0.15 W/m2K.
Furthermore, to comply with the Passport, all junctions in the home had to be detailed to a psi-value of 0.08 W/m2K or less.
Point 1 Building Systems used detailed 3D modelling to interrogate the requirements at the quotation stage and ensure an appropriate structural package was developed.
"The psi-values have been calculated showing the performance gain when the 25 mm layers of Thermapitch TP10 and Thermawall TW55 were installed internally. Working within the scope of Graven Hill Plot Passport, our SAP assessor was able to confirm the required performance at an early stage to prove compliance".
Geraint Edwards, Greenspace Architects
The home is also expected to achieve a measured air-leakage rate of less than 1 m3/m2hr @ 50 Pa. The OSB/3 facing of the TEK Building System panels, in combination with its unique cassette joint, can allow projects to meet this level of performance virtually out of the box. The inclusion of steel structural elements on this property, however posed additional challenges
“Further challenges were presented with a whole house MVHR system, whilst also co-ordinating the stair design and balconies. Careful design of both the envelope and services (shown below) was essential to ensure we maintained the psi values and thermal performance required to comply with the project passport.”
Garry Dyke, Director, Point 1 Building Systems
Daniel Frazer personally oversaw work to achieve the desired level of airtightness. This work included applying silicone and airtight tape to all junctions other than those between the TEK Building System SIPs. Steels were shuttered and filled with concrete maintaining the DPC/DPM between concrete and timber. Airtight tape was also applied to all joints between the internal insulation boards.
Page Reviewed 28/07/25
