Design engineers often don’t give enough thought to the project delivery method (PDM) that will take their contract documents from paper to production to reality for the building owner (client). In fact, many design engineer may not realize there are five project delivery methods: design-bid-build (D-B-B), construction management (CM), design-build (D-B), integrated project delivery (IPD), and performance contracting (PC).

These engineering-constructing methods each have their “pros and cons” and will influence the system design and role of the designer. So, why should HVAC design engineers give thought and decide on the appropriate PDM? Well, developing and producing a successful design will largely depend on the PDM because the client’s expectations for a successful project, teamwork and quality control, and the design team’s contract fee profit will be influenced and regulated based on the PDM.

This month, I will provide a brief explanation of the D-B-B method, which is one of the two most common ways to deliver a project. In the D-B-B approach, a client will select and sign a contract with a design firm, usually an architectural company, for a fixed or agreed-upon fee based on a percentage of the total cost of the contract. Now, there are several other versions of owner-architect contract agreements, but D-B-B is  the most common agreement to produce contract bid documents and provide construction administration.

For the HVAC consulting firm, the architectural firm will usually, if not always, negotiate a fee that allows the architectural firm to financially benefit from this negotiation because the consultant is a commodity unless the more experienced client specifically requires the architectural firm to hire a certain HVAC consulting firm.

When the completed contract documents are put out to bid, bidders may be preselected/pre-qualified or simply open to those construction firms interested in submitting their bids. Without pre-qualification requirements, the bidders can be a collection of good-fair-poor selections.

D-B-B is the most adversarial PDM approach because it pits the design team against the construction team during construction. This method is very common for clients I consider “uneducated,” or those who believe their best value is transmitted through competitive, extremely low bids. A more knowledgeable client’s selection may be based on the “best value” rather than the lowest cost. 

CM, D-B, and IPD offer more of a team atmosphere, where I would rate CM as good, D-B as better, and IPD as the best. CM is much more common than D-B and IPD, although it generally includes less teamwork and cooperation than D-B and IPD. During the design phase, a client will sign separate contracts with the design team and the CM firm, which enhances the goal of greater synergy between the two.