Unaddressed Site Conditions: Again, maybe the most important part of the Constructability review. Site conditions can change dramatically from the time a project owner conducts a site survey or an architect initially visits the site to the time of bid.
The documents reviewed on the LAUSD program consistently did a very poor job of illustrating the complete picture on site. Projects that involved additions or modifications to existing facilities suffer in particular from unaddressed site conditions.
Close attention needs to be paid to new construction integrating with existing construction. If new raceways are shown indicated intruding into existing areas, hazardous material mitigation, plenum space conflicts, or available panelboard space for new circuits need to be addressed.
Numerous times when new electrical or systems panelboards were to be added to existing electrical, mechanical, or LAN rooms, the rooms lacked the physical space to install the new panels. This portion of the review can not be stressed enough.
Other Issues: Other common errors and omissions consistently discovered in the audits or the reviews were failure to provide enough useable plenum space.
Project budget concerns resulted in reduced floor to floor heights while at the same time aesthetic design considerations increase ceiling heights. These two factors limit plenum space with the inevitable impact to ductwork, cable trays, and ceiling-mounted equipment.
Horizontal control (civil) information needs to provide benchmarks and centerlines and have sufficient dimensional information to locate all major building and site features outside of easements and right-of-ways. Site plans also need to consider adequate offsets to adjacent properties to prevent undermining of neighboring properties.
Electrical documents need to consider all miscellaneous power requirements - carbon monoxide sensors, high water level alarms, irrigation controllers, automatic overhead doors, and miscellaneous mechanical equipment. Owner-furnished kitchen or medical equipment needs to clearly define where the owner's "furnishing" scope stops and the contractor's "installation" scope begins.
Summary
The Constructability review should never target only the bid documents provided by the designer. Although the bulk of the documents bid will be produced by the architect/engineer, the effect of owner-furnished, utility agency, or environmental documentation needs to be concurrently reviewed.
The most qualified Constructability reviewers are those individuals that have dealt with the by-product of bid document errors and omissions in the field.
Superintendents, inspectors, or managers who have been involved in resolving unclear construction conditions or settling change orders and claims have an excellent background that can be applied in the up front Constructability reviews.
Their knowledge combined with some form of a Constructability checklist that is derived from audits of previous projects and changes are necessary for a comprehensive and successful Constructability review.
The checking or "backchecking" for incorporation of the Constructability comments by the designer has not been mentioned but is a natural activity to follow the Constructability review. Several meetings with the architect/engineer subsequent to the review may be necessary to resolve all of the comments. Consensus on whether to incorporate or not apply each Constructability comment should be reached by the project team.
The timing of the review needs to be considered as well. A review should occur when enough detailed information is available to conduct a Constructability review.
The 50% construction document stage and after the submittal of the 100% construction documents to the jurisdictional review agency are good milestone dates to conduct reviews.
Not as much information is available at the 50% construction document stage so the review should be pared to match the level of information provided.
The Constructability review, when conducted properly and focused on those issues that affect buildability, will pay for itself.
It can be difficult to quantify in dollars what the review has saved an owner since the stage of construction that the error is discovered has the biggest impact on its cost. However, you need only uncover a few of the major and recurring issues listed above to realize its value.
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