The Canadian Handbook of Practice (CHOP)
in Chapter 2.3.2 gives a good overview of the DB method of project
delivery, including advantages and disadvantages. As with Construction
Management projects, or any project for that matter, clarity in roles
and responsibilities is paramount to a successful project. However, with
both the architect and contractor working under a single entity of
‘Design-Builder’ this may become an internal discussion about their
agreement without an independent perspective and dependant on who leads
(the contractor or the architect) the DB entity.
The success of a Design Build project of course also depends on the
project requirements including programmatic, technical and budget
parameters, which would include performance specifications being well
defined without ambiguity at the outset. These are usually prepared by
an Owner with an Architect or another Consultant prior to the award of
the project to a Design Build company.
It is based on the above considerations that the successful Design
Build proponent (now a Contractor and another Architect) develops their
design and final specifications for the construction of the project
based on the specific requirements they are obliged to meet.
Ambiguities or conflicts in the parameters that may not be apparent
from the outset may be exacerbated in the final execution of a project,
for example where the performance specifications does not included
adequate provisions to meet the intended programmatic needs yet is
technically met in the final specifications of the project.
The writer recalls for example a situation that occurred on a trade
school project for a mechanics teaching shop. The owner’s requirements
included performance specifications for exhaust fans needed while the
car engines would be running (while teaching students). The fans
provided did meet the performance specifications, and came with an
internal or external (roof top) mounting option. The internal option was
implemented (perhaps saving the cost of some roof detailing, or in the
equipment itself). This, however, resulted in a practically unusable
condition in that the noise of the fans was far too loud for the
professors to teach their students while working on the vehicles (one
might argue, therefore not meeting the basic programmatic needs).
Unfortunately, noise criteria were not included in the project
requirements, perhaps based on a presumption that the exhaust fans would
be roof top mounted and noise was not considered to be a significant
concern.
There are usually multiple solutions that meet the stated
requirements, each with advantages and disadvantages as to cost,
performance, and/or meeting programmatic needs, and it may be difficult
to determine the best advice to give or the best solution to implement
for a client or an owner. The architect is cautioned to uphold their
professional obligations especially if under pressure from their client
(the Design Builder) to reduce costs.