Common-area takeoff omissions: corridors, stairs, underground parking and rooftops

Why common areas need a separate takeoff

Common-area wiring devices depend on the building layout rather than the dwelling-unit count, and often use specifications unlike those inside dwellings, such as weatherproof or surface-mounted types. Mixing them into the dwelling-unit sheet forces recalculation whenever the unit count changes and may conflict with BOQs that separate dwelling and common-area electrical work. Create a separate ‘Common areas’ sheet from the outset and divide its rows by floor and zone.

Frequently missed locations

• Typical-floor corridors and elevator halls: Cleaning outlets and hall-light switches. When applying a typical-floor plan across several floors, check the number of applicable floors.
• Stairwell: Paired 3-way switches and sensor switches on each floor. There is often a separate sheet for the stairwell.
• 1st floor lobby, mailbox room, security room: Some devices appear only on a separate plan or enlarged view.
• Underground parking: Weatherproof outlets, EV charging outlets and column-mounted switches. Each basement level has a separate plan, and ramp sections are easily missed.
• Mechanical, electrical, pump and generator rooms: Many devices are surface-mounted and may appear on building-services drawings.
• Rooftop and elevator machine rooms: Weatherproof outlets and switches. The rooftop plan sheet is often omitted from the count.
• Ancillary facilities (management office, community facilities, daycare): A separate building or drawing bundle can be missed in its entirety.
• Outdoor areas (site paths, parking entrances, refuse collection areas): Shown only on outdoor electrical drawings.

Use a sheet index to prevent omissions

Obtain the drawing-set sheet index first. Mark every sheet ‘Dwelling units’, ‘Common areas’, ‘Outdoor’ or ‘Not applicable’, and record when you start counting it. Request files listed in the index but missing from the delivery. If a file is present but absent from the index, check which version is current. This systematically prevents omissions such as never opening the rooftop sheet.

What to include when submitting to Voltix

Voltix currently focuses on apartment wiring-device quantities. Both dwelling-unit and common-area plans can be submitted in DWG/DXF. For common areas, provide the floor/zone divisions and number of applicable floors to establish the takeoff scope. For outdoor electrical drawings or other trades, Contact us first to check support.