Plan and Spec
with AT Mechanical
What is plan and spec?
Plan and Specifications (P&S) is the traditional method for project delivery and differs in several aspects from Design-Build. There are three main phases: the design phase, the bidding phase and the construction phase.
In P&S construction, it is the owner's responsibility to bring a feasible design to the construction team. In Design-Build, it is the design team's responsibility to design the building and build it. From the mechanical design aspect, the P&S process works well for projects where the design team has a lot of experience. This is great for design teams that have engineered the same type of project repetitively. The process also works well for specialty projects where little design knowledge exists or where there are extensive architectural, structural or other limitations to the mechanical design.
AT Mechanical works well on Plan and Specifications projects and is able to build your project exactly how it is drawn. Our experience with Design-Build allows us to understand the design process used by other mechanical experts and engineers on every project. We are always looking for ways to create value to the project owners and implementers.
Plan and Spec vs. Design-Build
In the Plan and Specifications (P&S) method of delivery, the owner of the project contracts with separate entities for design and construction. There are three main phases: the Design Phase, the Bidding Phase and the Construction Phase.
Design Phase
An architect or engineer designs and produces documents on which general contractors will bid and ultimately be used to construct the project.
- The architect works closely with the owner to identify the needs of the project and to develop a written description and schematic design drawings. This is further developed into a "biddable" set of plans.
- Various professionals are used to come up with the design and specifications for the project including structural and MEP (Mechanical-Electrical-Plumbing) engineers.
Bid Phase
The bidding phase can be "open" - any qualified bidder can participate -or "select"- few pre-selected contractors are invited to bid.
- General Contractor's (GC) receive the bid documents and contact various subcontractors to receive bids for sub-components of the project.
- The architect reviews bids, seeks out any clarification needed of the bidders, ensures that documentation is in order and discusses the ranking of the bids with the owner
- If the bid is acceptable to the owner, the owner can discuss the proposals further. The owner will not necessarily pick the lowest bid by a GC since past performance and quality of work also play a role in the selection process.
Construction Phase
Construction documents may have to be updated to account for addenda or other changes, but approvals must be achieved through the proper authorities in order to begin construction.
- The architect acts as an agent to the owner to ensure that the work is progressing appropriately and also to issue site instructions. Changes may be made to the drawings for price adjustments. Then the project is constructed, or in some cases, abandoned.
Proponents of the Plan & Spec's method claim:
- The design-build approach limits the client's involvement in the design.
- Contractors often make design decisions outside their area of expertise.
- A designer -rather than a contractor professional- is a better advocate for the client/owner.
- By having designers and contractors representing different perspectives and remaining in their separate spheres on influences, designers and builders ultimately create better buildings.
- The design-build procedure is poorly adapted to projects that require a complex and elaborated design for aesthetic or technical purposes.
What are the potential problems & Benefits?
Potential Problems:
- Failure of the design team to be updated with construction costs in excess of original design due to changes
- Redesign expenses can be disputed
- Tendency for General Contractors to seek out subcontractors who offer the lowest cost to ultimately end up with a "cheaper project"
- Disputes between the design team and owner
- Disputes between the architect and general contractors
Benefits:
- Design team is impartial
- Fairness to potential bidders and more options for the owner
- Engineers often help owners in the transition to building operation (e.g. reminding the owner to service the equipment regularly)
- When the "right" design is selected that represents that best value and the "right" contractor is picked, the competition for the work improves efficiency and quality for owners