The key to scheduling construction for a 12-day build-out is a patented engineered wood floor truss system that also serves as a foundation.

Scheduling Construction

For A 12-Day Completion

HBA editor's note:
This is from an article in Builder Magazine in 1982. So many of the figures are way out-of-date (who builds a house for $40,000 any more?). Also note that building codes have changed as well as HUD programs mentioned in the article. But the planning and scheduling principles are still the same. And, oh yes, wood foundations are still being built!

Al Bowen knows about scheduling construction. He builds houses so fast that he doesn't even get a construction loan. His houses are pre-sold. Construction starts the day after the buyer receives approval for permanent financing. Twelve days later the house is completed and the buyer goes to settlement before the construction bills come due.

Bowen built and sold 30 homes in Spokane, Wash., in two months after he introduced his 12-day schedule, and he has orders for 15 more. Because he pays no interest on construction loans and builds tile 960 square-foot ranches on inexpensive land. Bowen can sell the homes for $37,900 - $6,000 less than the FHA-appraised loan value of $43,900 and about $10,000 less than the market value.Bowen observed that many builders allot an entire day to a subcontractor when his job can be finished in hours. To save time, Bowen schedules subcontractors by the hour and has several trades working in succession on the same day. Now that's scheduling construction!

Cross Section of 12-day house

Floor trusses, studs and roof trusses are built 24 inches on center.

But the key to the 12-day construction schedule is a patented engineered wood floor truss system that also serves as a foundation.

"In this part of the country, wood is the least expensive building material in the house and concrete is the most expensive," said Bowen, head of Bowen Construction Co., Post Falls, Idaho. "I knew that if I could find a way to build a foundation of wood, I could save in materials and labor and simplify my schedule as well."Before he began using the truss system, Bowen worked with a 45-day construction schedule. He paid as much as $2,700 in interim financing interest. He developed the system after months of research.

Among the systems he investigated was the All-Weather-Wood Foundation (AWWF) developed by the NAHB Research Laboratory in conjunction with the National Forest Products Association and the U.S. Forest Service. He obtained information about the AWWF from the American Plywood Association.

Bowen ended up modifying the crawl space AWWF, and using trusses instead of floor joists. The trusses have integral legs and leg supports that are stamped together with the truss by metal plates in a factory.The legs extend down to concrete footings below the frost line and support the floor system. An assembled 24-foot truss weighs about 47 pounds, so one man can handle it. Bowen begins construction by excavating the crawl space and forming and pouring footings. The crawl space is covered with a 4-mil polyethylene sheet that serves as a vapor barrier.

The two end trusses are set with the bottom plate already attached. After measuring the distance between the two trusses, framers anchor the bottom plate to the footing with bolts or strapping.

Intermittent trusses are similarly set 24 inches on center and floors are decked as the trusses are erected. The two outside legs of the trusses are pressure-treated lumber. These are covered by pressure treated plywood cut lengthwise into 2x8 foot sheets to enclose the crawl space.

The inside of the crawl space wall is insulated with R-11 batts and the outside is caulked and painted with asphalt. Then the foundation is backfilled. Above the floor decking, Bowen builds a conventionally framed house following HUD's OVE design and construction principles. These include studs 24 inches on center, single top plates, two-stud corners with drywall clips and elimination of headers and cripples at doors and windows. Roof trusses are lined up 24 inches on center above the wall studs.

Bowen uses pressure treated wood studs to frame the garage, starting from the footing. Studs run from a bottom plate bolted to the footing to a single top plate. Half-inch pressure treated plywood is applied a minimum of 16 inches below grade and 8 inches above grade. A 2x6-inch wood border is applied around the inside of the garage to act as a form for the concrete.

Bowen saves further time in his schedule with the extensive use of jigs.

"Although my system and building methods let me build a small, low-cost house a lot faster, they will work with any type of house at any price," he said. "With the high cost of construction money, every builder is going to have to look for ways to build faster."

From Builder Magazine, November 1, 1982, P. 42



For additional insight to planning your construction schedule, see Lesson Nine of our online course

Successful Home Contracting

Return To Critical Path Method From Scheduling Construction On A 120-Day Schedule


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