The construction of the sales models should be used as a trial-run to identify and solve problems before starting construction of the productions units.  The sales models construction is the time to investigate and solve design, scheduling, and coordination problems.

Equally important is the cooperation of the city building inspectors in anticipating and identifying building code and engineering questions on the plans.  The builder should encourage the raising of any questions and issues the inspector may have during the construction of the four or five sales models…so that these are resolved once the construction starts on the 50, 100, or 200 production units.

The builder should take the lead and encourage the debugging of the models through the use of requests for information (RFIs) to the architect and structural engineer, constructability analysis of the plans, and the input of the city building inspector.

If the builder instead rushes through the models construction to get into the start of the production units…unresolved problems only multiply over several units rather than a single sales model floor plan.  If unresolved problems still exist in the plans…a change of building inspectors midway through the production units only exposes some latent/hidden issue that could and should have been identified and resolved earlier during the sales models construction.

The production schedule can then be held up resolving problems on several repeating units…sometimes affecting several trades…creating a ripple effect of debugging part-way through the production phase rather than problem resolution confined to a single sales models unit.

Finally, for multi-unit production tract housing and condominiums…changes to the sales models in terms of problems identification and resolution…and owners changes to the floor plans…should be memorialized in revised sets of plans re-submitted to the city or county plan checking department…so that plans reflecting the changes and corrections can be ready for use when the production phase begins.  Some cities or counties will not allow the production construction to begin until revised plans are complete…so that their inspectors are looking at the revised plans rather than old plans plus a number of architectural or engineering field memos or “cut-sheets”…which get to be too confusing for the building construction and the building inspectors to follow.