Every home should have zero defects, judging by the number of
inspections performed during the building process. Every trade contractor has multiple
inspections by crew chiefs, builder staff, code officials, and the homebuyer. In total,
there is more time spent inspecting and correcting than any other single construction
activity.
Each inspection is justified by the defects it finds, but leaves
enough undiscovered defects to justify the inspections that follow.
The first inspection assesses the quality of the craftsman’s
work. Done right the first time, further inspection is unnecessary. The inspections that
follow are not to inspect the craftsman’s work, but instead inspect the quality of
previous inspections. Statistically, only one defect out of 1,000 should make it past four
inspections when each inspection catches nine of ten latent defects.
Each trade is inspected more than four times. For example, think of
the number of inspections performed just for wall framing. The first is an in-process
inspection performed by the rough framing crew chief as each wall is built. As a phase is
completed, the crew chief performs a second inspection to make adjustments, correct
details and to add studs where necessary.
After the mechanical rough-ins, a series of frame checks are
performed. The framing contractor’s inspector marks defects left by the rough framing
crew and new ones created by the plumbing and HVAC trades. After those defects are
corrected, the job is inspected by the builder’s superintendent. Again the frame is
marked, punched out, and rechecked. Still Then another frame check is performed by a code
official to catch anything that might have gotten by. Five inspections so far and
counting.
After drywall and paint, the builder’s superintendent inspects
for cosmetic framing defects, such as bowed studs, that are telegraphed through the
drywall. When all is in order, the construction manager walks the house to be sure it is
ready for closing. The eighth inspection is made by the home buyer during the closing walk
through.
Wall-framing inspections are only a fraction of the total number
that are performed on a home before its completion. Because we are compelled to inspect
our inspections, cumulative inspection costs are high. Add the cost for correcting defects
and the total price to assure quality may rival the craftsman’s pay to do the job
itself!
Dollars spent on inspection and correction must be redirected to a
more cost-effective quality control strategy. The ISO9000 quality control approach can
help provide some answers. First ISO9000 helps to eliminate these defects by changing the
focus to do the job right the first time, reducing dependency on inspection. When
inspections are necessary, ISO9000 provides a thorough approach so redundant inspections
can be eliminated.
To provide builders and trade contractors with tools to apply
ISO9000 on the jobsite, the ISO9000 Builder Quality Alliance has started developing
Quality Plans for specific trades. A free ISO 9000 Builder Quality Alliance
"Quality Plan" is available from the NAHB Research Center.