Construction Documents (100%)
Construction documents (100%) represent the final set of drawings that will be issued for contractors to bid on. At this point, all architectural and engineering systems have been reviewed and designed to ensure that project goals are being met.
A final review with all members participating in previous reviews should be planned to ensure all information from previous design reviews have been incorporated into the construction documents and all other renewable energy integration issues have been resolved before being issued for bid.
At this point, it is expected there will be few, if any, changes to the overall building design. The planned renewable energy technologies will have been evaluated to ensure project goals continue to be met.
Engineering calculations and/or whole building energy simulations reflecting current design, as well as measures to further increase the overall building efficiency, should be reviewed at this and all phases of the design process.
It is suggested that separate energy simulation files be preserved at each phase of design to reflect the design documents at that point in time. Any changes incorporated into the current model should be documented with the simulation files. Changes may include operating schedules, architectural components, mechanical system components, or other energy end use systems, including process loads, that may not have been previously identified.
Value Engineering
Pricing will come back to the design team after construction documents are issued for bid to the participating contractors. Contractor bids that fall within the project's planned budget provide the assurance that project goals can be met without additional costs to the project. In cases when all contractor bids are coming in over the project's budget, the design team may need to reevaluate design decisions that may be adding to project costs.
Value engineering describes this scenario, or the process for scaling back design at any phase of the design process, but can be misleading when first-cost is the only consideration used to quantify value. A best practice is to consider life-cycle costs when conducting value engineering and to rerun energy simulations on any proposed cuts or alterations to energy systems. Unintended consequences can be better identified with re-run simulations.
It is easiest to ensure project goals remain in place when these goals are incorporated as a requirement of the project at its inception. Whereas significant costs savings can be realized with the replacement of particular mechanical system components, these typically result in less energy-efficient systems. The impact of the selected renewable energy systems are diminished and could ultimately require a larger system to meet previously defined energy goals for the project. Projected increases in annual energy use and the associated costs, as well as increased renewable energy system capacity to meet established project needs, should be considered when making such value assessments.
With the integrated design team, coming together to review and reevaluate the building as a system can create an opportunity for greater energy efficiency. When components need to be evaluated for cost effectiveness, all systems should be evaluated to determine the most energy-effective way to bring the project within budget while preserving the project's goals. For example, rather than changing the systems designed to handle specific building heating and cooling loads, it may be more cost effective to look at architectural components, including wall assemblies, glazing, and shading strategies that may further reduce equipment size and associated costs.