Summary
• The garden cube is built with SIPs.
• It uses OSB, rather than plywood.
• It can be erected on site, or craned in complete.
• Bespace is exhibiting at Grand Designs Live from October 9-11.
So when is a shed not a shed? According to Bespace Urban Design, it’s when it’s a ‘garden cube’ built in modern structural engineered timber panels.
The brainchild of brothers Mark and Neil Warburton, Birmingham-based Bespace launched two years ago to create bespoke garden buildings dripping with green kudos.
“Anybody can put up a garden building, so from the outset we asked ourselves how we could be different,” said Mark Warburton. “Our aim was to build truly bespoke ‘cubes’ using the most innovative, environmentally sound materials from start to finish.”
This concept led to Bespace opting for structural insulated panels (SIPs) as its core material. The particular type comprises two 12mm sheets of OSB bonded either side of a slab of polyurethane insulation. These are pre-cut to Bespace’s specification by its unnamed supplier and delivered to site ready for erection.
“They come in 600mm and 1200mm wide cassettes and are very easy to handle and quick to build with,” said Mr Warburton. “The polyurethane thickness depends on the required U-value, but with a 150mm overall panel we can achieve 0.17.”
Bespace, he added, is also particular about its SIPs using OSB rather than plywood, which has made it something of a poster boy for ‘JOSB Done’, the generic OSB promotional campaign.
“The quality and accuracy of OSB is consistent, while you can struggle with plywood panels with voids, splitting and weak spots,” said Mr Warburton. “We also know the timber is from a sustainable source as it’s FSC-certified, whereas there are issues with certain plywood imports, which Greenpeace highlighted in its Setting a New Standard report last year.”
The cubes are set on a reinforced concrete base, with the SIPs fixed to a timber sole plate and screwed and glued to each other. The roofs are then covered in RubberBond EPDM sheeting and finished to the customers’ specification, which so far has ranged from aluminium to sedum.
“The core structure can be weathertight in two days, ” said Mr Warburton, “and, to cut site time even further, we can construct the cube and crane it in, complete, depending on the size, with doors and windows already fitted”.
Internally the buildings are finished in plasterboard, ready for painting, or oiled birch ply, and flooring to date has included solid wood, laminate, carpet and, upping the green kudos, recycled rubber. Externally they are wrapped in DuPont Tyvek waterproof breathable membrane, before cladding in unfinished western red cedar.
The cubes also come ready wired with a ring main of double sockets and a lighting circuit running from a small consumer board.
“In freestanding versions we also fit wall-mounted electric heaters or heating and cooling ‘climate control systems’, which can be low energy inverter driven,” said Mr Warburton. “And final fit out can include kitchenettes, shower rooms, toilets and roof lights.”
The more complex the finish, he added, the longer it takes, but generally the cube is ready for use in a week.
Despite the recession, Bespace has a “very healthy order book” , something it puts down partly to the versatility of its buildings. To date it has supplied them as home offices, therapy, music, entertainment and play rooms, gyms and summerhouses. And, in the current threadbare housing market, it is also targeting the ‘improve not move’ customer, promoting cubes as multi-purpose extra space to homeowners who can’t see immediate prospects of stepping up the property ladder.
“Evidence of the strength of this demand are increasing applications for garden building planning permission – although we usually design ours so they don’t need it,” said Mr Warburton.
The company also sees scope for developing the cube concept. It is already supplying them as house extensions and has now delivered a classroom.
“Using SIPs gives us great flexibility in terms of design and size,” said Mr Warburton. “The average cube is 2.4×2.4m, starting at £9,995, but the classroom is 12×7.5m and single span. Build speed and green credentials make them ideal for schools and we’re getting a growing number of enquiries.”
Bespace, he added, is also expecting another market boost from its second outing at that Mecca for UK eco-construction, the NEC Grand Designs Live from October 9-11. This looks like the perfect match for our cash-strapped times; all the modern-living, green allure of Grand Designs, encapsulated in a quick-build, economic cube.
