In today’s fast-paced construction environment, many building designers are opting for Design & Construction (D&C) project delivery as opposed to the process of Full Design and Documentation. Yet in light of recent issues regarding building quality and compliance, is this really a good idea?
Design & Construction project delivery does come complete with its share of intrinsic benefits. These include an abbreviation of project design development and delivery time, lower costs, less design detail, creative and innovative design and construction methods, optimisation of design and construction, and a reduction of project delivery cost.
On the negative side, users have little input in the design process, and a limited ability to produce detailed designs that meet all client and user needs. Cost-cutting measures might be employed at the expense of project quality, and inferior, inexpensive building projects might be used to save time and money. On a related note, time and budget constraints—along with skimpily detailed plans–might lead to poor design and construction outcomes.
In the traditional design process, an experienced team of trade contractors documents related works and remains invested in the project through every phase and cycle. With Design and Construction, the engineer and design team are enlisted to ascertain client brief requirements and provide some design, scoping and performance requirements. The level of design development here is more limited, and may be as low as 30 percent of the overall process. This could include a basic performance brief that includes functional and performance requirements, building sketches and diagrams, and—in more advanced cases—a works specification outline specifying basic quality requirements, a description of works and systems to be featured in the project, such as fire, power, security, etc., equipment needs, and contractor requirements.
What this plan likely would not include would be finalised sizes, dimensions, service outlets and equipment design capacity.
The contractor must draw upon this brief as a reference plan that will oversee the design and delivery of the built work, while themselves putting the finishing touches on design details and incorporating these changes into the plan.
The D&C design team might go on to become an advisory and review team for the duration of the project, reviewing designs and work submissions and offering advise on quality and compliance. They may be enlisted by the client or contractor, with both options boasting pros and cons.
In a traditionally designed project, plans for minute details like the quantity of fittings, mounting, capacities, work notes, etc., would be specified, while leaving other areas less defined.
A switch to D&C might produce inconsistent levels of design detail as well as confusion in pricing requirements and allowances. This, in turn, can lead to variation claims and general confusion.
A D&C contract arrangement can restrain the client from making refinements and modifications to the design plan without forking over substantially more money. And they may have limited communication with the design team.
In addition, the design team might feel creatively limited in terms of their design choices, given restrictions in their funds and schedules.
If a project involves standard, uniform design processes and little complexity, then D&C delivery can be a highly effective construction model. It also can work for more complex and advanced projects, such as labs and schools, but only if documentation is more thorough and detailed, and allowances are made for variations.
Regardless of the design and construction plan that one chooses, these factors must be ensured and guaranteed before the project is commenced:
- Top quality equipment and systems,
- Economic allowances of changes and variations,
- A talented, experienced team,
- A detailed and sufficient plan of design,
- Room for client input—and endless client satisfaction.