Optimum Design and Production of Two-Storey Timber Framed Housing

Abstract

The demand for housing in the last decade has resulted in the increase of Industrialised methods of construction. Industrialised methods have reduced manhours per dwelling from the region 1200 to2000, to the region of 600 to 900. However, costs have tended to be higher for industrialised methods, and even though standards are better the change from traditional to industrialised has been slower than expected. The timber framed house offers the best solution to productivity, since the manhour content is half that of any traditionally built houses. The man hour content for timber frame housing is in the range of 500 to 800 hours for the average 3 person 5 bedroomed house. The cost per square foot or square metre is lower than any other form of housing now that Parker-Morris standards are mandatory. This means that the present growth of demand is likely to increase. The manufacturers of timber framed housing for Local Authorities are trying to compete for orders by adopting various degrees of mass production. Hitherto there has been no data available to substantiate the production and erection techniques undertaken and this has. resulted in uneconomic methods. Detailed data below shows that mass production of timber frames is unwarranted. Flow line production, which is thought to be the ultimate in manufacturing, is more costly than manual batch production. Temporary site factories are more economical than permanent factories, reducing both the cost of production and the cost of transportation. Manual erection is not out-dated, it compares favourably with crane erection, for the present methods of design. Profits are reduced by bad planning, expensive scaffolding and inadequate allocation and control of preliminary budgets.