Research Report on Construction Methods

Three frame and three masonry houses were constructed by a variety of techniques in order to determine what assembly methods, or combination of methods, would yield the lowest cost structure. In order to compare methods more exactly, an accurate time-study was made covering all operations at the construction site. The combination of methods giving the minimum number of man-hours resulted in a saving of nearly twenty per cent of the total on-job labor. No special tools, mass buying or mass assembly were tried. All improvements were limited to such techniques as could be practiced by a builder who constructs from one to four houses per year. Greatest savings were obtained when all materials possible were cut from schedules and detail drawings, rather than from field measurements taken as the job progressed. Pre-assembly of parts, both on the site and off the site, follows naturally after pre-cutting of material. The "single room" technique was used with great success. With this technique, exterior walls and roof are erected first. Before any interior partitions are erected, wall finish material, ceilings and finish floor are installed; plumbing, heating and wiring are started. Roof trusses make the "single room" technique possible and, in themselves, offer a means of saving both material and labor. Engineered plans - detailed to take advantage of advanced modular materials construction methods and the savings possible by their use - are a primary requisite to cost reduction. Selection of materials which lend themselves to modular construction methods is likewise a prerequisite.U.S. Department of Commerce, Office of Technical Service