Converting an older office building or mill into apartments is one of the most active segments of multifamily construction in Connecticut’s downtowns. The structure, the location and the character are already there. What is not there is an electrical system designed for 150 kitchens, 150 bathrooms and 150 people who all come home at six o’clock. Here are the issues we see on nearly every conversion, and the ones that most often turn into change orders.
The existing service is almost never reusable as-is
Office buildings were served for lighting, plug load and HVAC with one tenant per floor. Residential load is different in character: electric ranges, dryers, in-unit heat pumps and water heaters, plus a meter for every apartment. In most conversions the service is replaced, the utility transformer is upsized, and a meter room has to be found in a building that was never designed to have one. Getting the utility involved during due diligence, not after closing, is the single best cost-control step.
Vertical pathways
New construction gets chases designed in. Conversions get whatever the original building left behind: a couple of pipe shafts, an abandoned dumbwaiter, or nothing. Every apartment needs a feeder, data, fire alarm and often low-voltage pathways from the ground floor up. Finding or creating vertical routes through post-tensioned slabs, historic floors or cast-iron structure is a coordination problem between the electrical contractor, the structural engineer and the architect, and it has to be solved before the drawings are priced.
Ceiling height and what is above it
Residential layouts want flat ceilings. Office buildings hide ductwork, sprinkler mains and old conduit above a dropped grid. When the grid comes down, every one of those runs is either in the way of a new wall or in the way of a new ceiling. The electrical rough-in has to be sequenced around the mechanical and sprinkler trades more tightly than on a ground-up building.
Unknowns behind the walls
Abandoned wiring, undocumented circuits, asbestos-wrapped conduit, knob-and-tube in a wing nobody knew was original. A pre-bid walk-through with the ceilings opened in a few representative areas is worth more than any amount of drawing review. Where that is not possible, a contingency line specifically for electrical unknowns protects both the owner and the contractor from a dispute later.
Life safety in an occupancy change
Changing a building from business to residential occupancy triggers residential life-safety requirements: interconnected smoke alarms in every unit, carbon monoxide detection, emergency lighting in corridors and stairs, and typically a full fire alarm system replacing whatever the office had. On historic buildings, the fire marshal’s requirements and the preservation requirements sometimes pull in different directions, and the electrical contractor ends up in the middle. Raise it early.
What makes conversions go well
- Utility engagement and a service plan during due diligence.
- A pathway study (vertical and horizontal) before the architect finalizes unit layouts.
- Selective demolition in a few areas before the bid, so the contractor is pricing what is actually there.
- A metering decision made early, because it determines the meter room and the feeders.
- An electrical contractor who has done it before and knows which surprises are normal.
Sunderland Electric’s conversion work includes The 55 Elm Club in Hartford, where historic office buildings became apartments. See our projects or send us your drawings for a conversion you are evaluating.