Planning for an overbuild, Part one: MEP considerations
Many healthcare facilities have been built with the foresight of future expansion, which usually means a relatively large investment in oversized building MEP system capacity or distribution components. However, when the need arises to expand, the facility is usually fully occupied with active MEP systems and a lot of daily activity that cannot be disrupted. So what are some things to consider when undertaking an overbuild or vertical expansion project? The answer is in careful planning.
Lessons learned from some of our past projects have taught us that when planning an overbuild project, it helps to consider the following:
- Utilities: Review the existing utilities that will be extended and have your MEP contractors involved to ensure constructability, planning outages, and verifying capacities.
- During the design phase, you need to have a thorough analysis of the use of existing mechanical rooms and other MEP infrastructure versus building a new "plant" as part of the vertical expansion. If you decide to work with what you have, be prepared to do "forensic" testing and balance work in order to gather real data on existing equipment performance.
- If it’s an inpatient unit being built over an existing patient unit, it makes life so much easier to have shared headwalls on the new floors coincide with shared headwalls on the existing floors. This sets up a scenario where you only disturb two rooms below at a time to extend services upward.
- Vertical expansion may cause changes in the overall smoke and fire compartmentalization scheme. These changes must be documented and reviewed with hospital personnel so they understand what is changing (for their JCAHO SOC purposes).
- Investigate the existing conditions for all of the tie-ins as soon as possible, both in terms of their physical condition and ability to connect, and their capacity. Verify what work will need to be done within the lower floors to extend utilities.
- Is electrical service adequate? How will new gear be installed while old service continues to operate? Plan and communicate all shutdowns and switchovers carefully.
- Evaluate the fire pump to see if it needs to be increased to deal with increased building height. Develop a plan to replace it and keep the old one running.
- Where you need to cut holes in the concrete structure for shafts, survey first for electrical lines buried in concrete structure. In the past, that was an economical method of installation.