Intelligence gathering

Summary
• James Jones’s IntelliRoof system is being used in the volume housebuilding market.
• Five IntelliRoofs can be installed in one day.
• RoofSpace’s I-Roof is based on the IntelliRoof.
• IntelliRoof makes a room-in-the-roof an easy option.

James Jones & Sons’ highly insulated, prefabricated JJ-IntelliRoof system, developed by the company’s in house engineers, and using the company’s UK manufactured, FSC-registered I-joist, is being used in some high-profile projects in the public and private sectors.

These include a major development by David Wilson Homes for the Joseph Rowntree Foundation at Derwenthorpe; and a highly successful pilot project, called the Glasgow House, by PRP Architects for City Building, which is using building design and technology to address the critical issue of fuel poverty in the city.

Equally importantly, three top UK housebuilders are also using the IntelliRoof in the volume market; and demand is such that key fabricating partners for the system now include National Hickmans and North Yorkshire Timber.

Originally designed for a limited range of applications, the system is now being produced in long spans, for example for Derwenthorpe; in hipped roofs; and for what James Jones Timber Systems Division business development manager Mark Tilston describes as “lots of more interesting and non-standard roofs”.

Time and cost benefits

Manufactured using prefabricated roof panels, floor cassettes, and spandrel panels, the IntelliRoof is proving particularly popular in terms of speed and cost of erection. “Builders look at the bottom line – and Intelliroof means there’s a lower cost in erection,” said Mr Tilston, adding that, in terms of speed, the record to date is five IntelliRoofs erected in one day.

In conjunction with specialist roofing contractor Roofspace Solutions, James Jones Timber Systems has participated in the development of a high performance prefabricated roofing system, the RoofSpace

I-Roof. This is being used by David Wilson Homes in a mixed development of 64 for sale/to rent homes for the Rowntree Foundation at Derwenthorpe, which are required to comply with Code for Sustainable Homes levels 4 or 5.

Developed using James Jones’ IntelliRoof system, the RoofSpace I-Roof is being used at Derwenthorpe to fit a particular David Wilson Homes’ house type. The innovative roofing solution incorporates roof cassettes that span 12m and which deliver a U-value of 0.15W/m²K and spandrel panels that deliver a U-value of 0.17W/m²K.

Patrick Wilson, design manager with RoofSpace Solutions, explained its approach when supplying the IntelliRoof-derived RoofSpace I-Roof to David Wilson Homes:

“We take a holistic approach to the design of our system,” he said. “We were keen to promote how our system interacts with all other elements of the building as this consideration ensured all associated products were working together, in order to successfully pass the stringent fabric requirements at Derwenthorpe.”

Addressing fuel poverty

Another housing development, the Glasgow House project, aimed to significantly reduce energy consumption costs and address fuel poverty. Monitoring outcomes confirmed it is performing far better than current regulatory levels require.

The pilot project, a three-way partnership between PRP Architects, City Building and Glasgow Housing Association, consists of two masonry houses, and two highly-insulated timber frame houses.

Both house types used the IntelliRoof, which combined highly insulated JJI-Joist pre-fabricated roof sections; 300mm Rockwool flexi insulation; and either concrete or rubber roof tiles, the latter manufactured from recycled car tyres. Designed to deliver U-values of 0.13W/m²K, the roof structure also offered the potential of a highly-insulated loft space for future adaptation.

Jim Cooke, City Building’s head of design and partnerships, explained that the IntelliRoof’s capability to host a room-in-the-roof made specifying the product an easy choice.

“It’s what we like to call the Glasgow House’s ‘hidden secret’ – from the outside it looks like a two-storey building, but thanks to the IntelliRoof we have been able to accommodate a third storey,” he said.

IntelliRoof’s prefabricated manufacturing process also brought benefits. “Attaching a roof to a building is usually a stick-by-stick process, but we were able to simply crane in the IntelliRoof, which saved a significant amount of time,” said Bryan Galloway, City Building’s head of new housing construction. “It also reduced the risks associated with on-site construction.”

Prefabricated flooring

James Jones has also worked recently with timber frame manufacturer Frame Tech Structures Ltd to provide prefabricated flooring solutions for a three-storey, 40-unit care home in Manchester, where Frame Tech is providing the structural timber frame. As the developer required the project to meet BREEAM Excellent standards, Frame Tech is supplying

a highly-insulated timber frame and is manufacturing and supplying 350 insulated floor cassettes, incorporating some 11,000m of JJI-Joists.

“Because the JJI-Joists can accommodate varying levels of insulation as required, they, together with the timber frame, make a significant contribution towards the completed building achieving its target of a BREEAM Excellent rating, exceeding Part L energy requirements,” said Mark Tilston.