An Irish company has developed a quick and easy way to get an extra room for outside your home. Called Shomera and designed by Creative Housing Solutions (CHS), these rooms are installed in three days and, being smaller than 247 sq. ft, generally don't require planning permission.

Shomera comes in eight sizes ranging from 93 sq. ft to 244 sq. ft and costing £5,850 to £9,950.

Construction consists of nine 18-inch deep holes filled with concrete and straddled by metal beams. The floor section is then strapped to the metal beams ensuring that the chamber is around six inches off the ground, thus negating any rising damp.

Shomera's 15 sections are built off-site and can be quickly assembled. They include a roof with a 20-year guarantee, double glazing, gutters, plastered and pine trim, electrical fittings and phone socket, and five-layer walls that are 5 1/2 inches thick. The height from floor to apex is 8 1/2 feet and the room is well insulated.

Eileen O'Sullivan of CHS says Shomera is ideal as an office, outside playroom or teenage retreat. "They are larger than your typical shed, are like a timber-framed house and most people go for the largest model, which works out at around £40 per sq. ft. Each unit is fitted with five-lever locks and can be alarmed as part of the house alarm or separately."

Once complete, Shomera needs a connecting electricity and phone cables from the home to be fully functional. Eileen O'Sullivan says CHS leaves them "ready to decorate with the wooden beams prominent on the inside" and believes "there is very little disturbance involved in installation".

CHS serves the Dublin area, has a website - www.chs.ie - and from order to installation Shomera currently takes between eight and 10 weeks.