There are two basic types of specifications. Design specifications provide precise, detailed instructions, which the contractor must faithfully follow in order to meet its contractual obligations. Performance specifications stipulate end results – capabilities and characteristics – which the contractor must achieve. The contractor must use its own experience and expertise to determine the best means and methods for achieving those results.
Performance specifications might seem beneficial to contractors, allowing more discretion and flexibility. In many ways, however, performance specs impose risks not presented by precise design specifications. This was illustrated in a recent California case.
A structural concrete contractor had difficulty working with self-consolidating concrete specified for areas where the concrete wall would serve as the finished exterior of the building. The contractor claimed the public project owner breached the implied warranty of the sufficiency of the plans and specifications. The court noted that the specification gave the contractor discretion to determine the final mix design and the method of placement. This was a performance specification. The owner extended no implied warranty of the design.
The other case in this issue involves proof of delay to work on the schedule’s critical path. A pre-construction schedule approved by the project owner and a post-construction schedule prepared by the contractor’s scheduling expert did not, in themselves, establish the critical path of the work as performed.