Raising the roof
Published: 06 April, 2007
As housing densities and the cost of land rise, using the roof space as living space is a growing trend. Keren Fallwell reports
Traditionally a place for the flotsam and jetsam of family life, the roof space in houses is increasingly providing extra living room.
Set above the main activities of the house, a room in the roof can provide an oasis of calm for a study or extra bedroom or, depending on the size, perhaps a master bedroom with en suite or a fully fledged office. Whatever the choice, a room in the roof provides extra floor space without adding to the footprint of the house. In fact, the Trussed Rafter Association (TRA) says that using room in the roof (RiR) trusses can provide up to 65% more living space.
And these days, as the price of land is rising and the size of plots is diminishing architects and housebuilders are keen to make optimum use of what's available. Wolf Systems, which supplies timber engineering manufacturers, estimates that 45-50% of new houses now include a room in the roof space, and that figure will continue to rise. Set against the NHBC's completions for 2006 at 184,900 8% up on 2005 the figure is significant.
The TRA says that RiR trusses, on which it can supply comprehensive technical detail, provide a simple and effective way of providing the structural roof and floor in the same component. What's more, it maintains, they are a tried and tested construction product that has been in common use for around 40 years
The only note of caution is that, where possible, the size of RiR trusses should be within the limits dictated by safe transport. Local conditions may affect this, but generally a truss of 4m is easy to transport. If greater height is required then trusses can be constructed in sections and joined on site.
Ridgeons Forest Products gets around this problem with low loader trailers that allow the company to transport 4.2m-high trusses. This, said Paul Ames, general manager of the timber engineering division, removes the need to place a top hat on the truss on site.
Room in the roof trusses are an effective way of providing the structural roof and floorOver the past 18 months the company has seen definite growth in demand for attic trusses. While they cost more than other trusses, the extra cost is covered by the additional square metres gained and the improved value of the house.
While Ridgeons' designers can provide their expertise, Ames said architects are also now taking on more of the design and specification responsibility for an RiR project, backed up by the truss manufacturers technical and
product knowledge .
Last year Ridgeons supplied long span RiR trusses for the construction of a 10,000ft2 seven-bed house in Billericay in Essex.
The 61 trusses were fabricated with a front to back span of 13.6m, creating an 8m-wide open area within the roof space, providing two large bedrooms and bathrooms, plus a lobby area.
The design also required the fabrication of 30 flat tops plus mono-pitch trusses to form a roof at lower level to cover a swimming pool and guest suite.
Covers Timber Structures has also seen increasing demand for attic trusses over the past few years. It's got to be the cheapest way to enhance the living space, said sales and marketing director Wally Shaw.
The appeal of attic trusses has also been helped by more user-friendly design and architects becoming more aware of the potential of trusses, he said.
At a Bellway Homes development in Coventry RiR trusses helped to satisfy site and planning constraints.
Bellway needed to use the roof space for accommodation as the site was constrained by mature trees carrying tree preservation orders, which limited the footprint of the buildings.
The RiR trusses, which were manufactured by H&S Systems, had spans of up to 8.5m. They were used in 14 of the 27 homes, with the largest sections employed on five- and six-bed properties. About 32 trussed rafters were used per home.
A room in the roof provides extra living space without extending the buildings footprintThe rafters, designed with stubbed ends to achieve maximum heights within rooms, were formed in two parts to ease delivery on site and handling.
The growing popularity of using roof space for living space is reflected in the changing sales patterns at window manufacturer Velux. A few years ago the large majority of contracts were for loft conversions, said Keith Riddle, Velux UK Ltd managing director Britain and Ireland, whereas today newbuild accounts for around 20% of the company's business.
You only have to take a drive around any housing estate and look up to see the number of rooms in the roof, said Riddle.
Velux, which last year won a Queen's Award for Innovation for its design service, has tens of thousands of products in its range but the timber window which pivots in the middle is the most popular in the UK. For most applications, it will do the job, said Riddle.
In addition, Velux offers top pivoting windows, electrically operated, solar operated and balcony windows, with standard glass, laminated glass or glazing designed to reduced UV light, and combination systems where windows can be bolted together to form a larger feature.
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