Aurelia Tower

A new high-rise rental building on an urban infill site, with roughly 250–300 apartments from studios to two-bedroom homes, a share of them permanently affordable, plus shared amenity spaces on the lower and upper floors. It is a design-build project: the contractor is the engineer of record, so every load, airflow and pipe size has to be calculated by the trades and coordinated in Revit, to California's Title 24 energy code and Plumbing Code.

We laid out the heating and cooling for every apartment type: VRF heat recovery fan coils for the larger homes, with room-by-room airflows for living rooms, bedrooms and baths, and packaged terminal heat pumps for studios and one-bedrooms. The VRF condensing units are grouped and stacked so each typically serves three floors, with separate units for the amenity spaces — over 200 tons and around 100 indoor units in all. Energy recovery ventilators serve the corridors and shared spaces, and we scheduled the garage and smoke exhaust and the stair pressurization fans. On the plumbing side we sized domestic water and drainage to the California Plumbing Code and laid out the domestic water risers: booster pumps in the basement with reduced-pressure backflow preventers, three pressure zones (basement to level 4, levels 5 to 13 and levels 14 to 20) controlled by pressure-reducing valve stations, and the top amenity floor on its own branch. Hot water comes from a bank of air-source heat pump water heaters and storage tanks, with a thermostatic mixing valve, recirculation pumps and a return on every hot water riser. A greywater treatment system with its own booster pumps supplies separate non-potable water risers to the apartments and make-up water to the mechanical equipment, and each service is submetered. The electrical design uses two 277/480 V three-phase services (4,000 A for house loads and 2,500 A for the homes): the residential switchboard feeds two 750 kVA step-down transformers and busway risers to apartment meter banks on alternate floors, each unit with its own 100 A meter and breaker, with separate transformers for EV charging and the parking stackers and energy-use metering by load type. Two paralleled 600 kW diesel standby generators with eight hours of fuel carry the emergency, legally required and optional standby loads through separate automatic transfer switches, with a docking station for a temporary generator. For fire protection the tower is fully sprinklered to NFPA 13 with quick-response heads in the homes and a Class I wet standpipe, fed by two electric fire pumps with jockey pumps on dual fire services, plus a fire-water storage tank sized for the stacked-parking demand and hose streams, with fire alarm to NFPA 72.