PE review required. Sample illustrative output. Every recommendation here must be reviewed and stamped by a licensed Professional Engineer before use in any bid commitment or construction document.
Fairmount Medical Office Building HVAC Retrofit
Mechanical · HVAC retrofit
Why bid: We self-perform the hydronic rough-in, terminal units and equipment setting, but the rooftop rigging and the occupied-building phasing sit outside our typical envelope — a crane pick over an active operating suite and ten months of night work. Controls are by the owner's building-automation vendor, so our scope stops at the terminal. Bid only with the rigging and infection-control contingencies carried explicitly.
Six-story, 148,000 SF medical office building replacing its 1998-era constant-volume system with a 4-pipe VAV retrofit across 22 zones. Four new rooftop air-handling units replace three aging units, served by a new chilled- and hot-water loop routed up the existing north stair shaft. Halston Construction Partners, the GC, keeps the building fully occupied throughout — clinical suites on floors 2-4 mean nightly containment and negative-air work under the owner's infection-control plan. Rooftop structural capacity has been investigated; two of the four unit locations require curb reinforcement by others. Controls integration is by the owner's building-automation vendor, and our point of interface is the terminal wiring. Ten-month phased schedule with tenant-occupancy milestones on the clinical floors.
The structural report flags the southeast and northwest unit locations. Reinforcement and the new curbs are owner scope, but our rigging plan and crane day depend on them being installed first.
Risers reuse the stair shaft and require firestop-rated sleeves at every floor. Routing is tight — a single field dimension drives the riser fabrication, so verify shaft dimensions before releasing pipe.
Clinical floors 2-4 require negative-air containment and nightly shutdown windows. Labor is loaded at a night-shift premium across roughly 60% of the duration.
Rooftop VAV air-handling units on a new 4-pipe hot/chilled-water loop
Rooftop curb reinforcement (owner scope) not ready on the crane date
HIGHMitigation: Gate crane mobilization on written confirmation that reinforcing is complete; carry a demob/re-mob allowance for one slip.
Occupied clinical floors force night work and containment cost
HIGHMitigation: Price the night-shift labor differential and containment build into the base; exclude tenant-relocation cost.
Building-automation integration responsibility is split from our scope
MEDIUMMitigation: Confirm the point-of-interface schedule before bid; exclude controls programming and head-end work.
Riser shaft dimensions differ from the design drawings
MEDIUMMitigation: Field-verify the shaft before releasing pipe fabrication; carry an allowance for one re-route per floor.
Who provides and installs the structural curb reinforcement and new curbs?
HIGH priorityStructural notes assign reinforcement to 'others' without naming a party. $90-140K scope if it lands on us.
Is the rooftop rigging and street-closure permitting in scope?
HIGH priorityBid form is silent on rigging and street closures; the units must be set over an active entrance. $55-80K depending on responsibility.
Confirm the controls boundary — terminal wiring only, or building-automation programming?
MEDIUM prioritySpec 23 09 00 assigns the head-end to the owner but RFP language implies contractor integration. Changes the package by ~$120K.
- Rooftop air-handler procurement and crane rigging with street closures
- Night-shift labor differential for occupied clinical floors
- Hydronic pipe and terminal-unit labor — 164 VAV boxes, ~9,400 LF
- Infection-control containment build and daily negative-air setup
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