What Is an Office Electrical Upgrade?
An office electrical upgrade adds distribution capacity and reorganises it, to the standard the Ontario Electrical Safety Code (OESC) sets, so tenant space can be powered, changed and metered without reopening the base building every time. In practice that means new feeders and per-floor or per-suite subpanels, added circuits for workstation density and equipment, and dedicated feeds for server and network rooms.
The technical work is rarely the hard part. The hard part is doing it in an occupied building. Feeders and panels can usually be installed alongside the existing distribution during normal hours, but the cutover, the moment the load transfers, has to happen when nobody is working. Where critical systems cannot drop at all, temporary power carries them through.
Office work also lives inside a coordination layer that residential work does not have: building management access, elevator bookings, after-hours work permits, tenant notification and landlord insurance requirements. We handle that layer as part of the job.
For the commercial range, see commercial electrical panel upgrades.
Typical Scopes
- Added circuits and one subpanel. A single tenant growing into their space. The smallest useful scope.
- Per-floor or per-suite subpanels. Multi-tenant floors where each suite needs its own distribution and schedule.
- Service upgrade with phased cutover. Where base-building capacity is genuinely exhausted. See 200A to 400A service upgrades.
- HVAC feeder upgrades. Rooftop unit or air handler replacement where the new nameplate exceeds the existing feeder.
- Staff EV charging. Load study, chargers and often load management across them.
When an Office Needs Electrical Work
- A tenant fit-out is planned. Partition changes, new workstation layouts and meeting-room technology all add circuits.
- The distribution panel has no spare positions. The usual first symptom, and the reason the next small change becomes a project.
- A server or network room is being built. Dedicated feeders, clean separation from lighting circuits and often a small UPS distribution arrangement.
- HVAC is being replaced. The most common trigger for feeder upgrades in Toronto office buildings.
- Breakers trip when equipment starts. Usually a sign that circuits were extended rather than added over the years.
- Staff or visitor EV charging is on the agenda. A capacity study before a charger decision.
What Drives the Cost Between $5,000 and $15,000
Number of subpanels and feeder runs is the main driver, because each one is a conduit route through risers and ceilings plus a termination at both ends. Cutover constraints are second and often decisive: after-hours labour and temporary power both add real cost, and they are the difference between a quiet upgrade and a disruptive one. Base service change is third, since a service upgrade brings the utility and a CT cabinet into scope. Building access is the fourth, particularly in towers where material has to move by service elevator on booked windows.
The ESA plan review, the after-hours premium and any temporary power are itemised separately in the quote.
What to Expect Through the Project
We start with a tenant load review: workstation density, equipment, server room, HVAC and any kitchen or charging loads, turned into a calculated load per suite. From that we plan the distribution, prepare the single-line diagram, and submit the commercial ESA plan review. Where the base service is changing, the utility service application goes in at the same time.
Installation happens alongside the existing distribution wherever the layout allows, so the live system is untouched until the cutover. Feeders are pulled through risers, subpanels set in electrical rooms or suite service closets, and circuits run to their positions. Work inside occupied suites is scheduled suite by suite with the tenant.
The cutover runs in the agreed window, with temporary power carrying critical loads if that was scoped. The ESA inspector attends, and you receive as-built panel schedules per suite, the final single-line diagram, the Certificate of Inspection and the itemised invoice for the building file.
Panel Upgrades for Office Fit-Outs: Workstation Density, Server Rooms, Meeting Rooms, and Shared HVAC
An office fit-out puts specific load types in front of the electrical designer, and the panel upgrade scope has to match the tenant plan. Toronto and GTA office fit-outs typically follow a defined pattern of subpanels, circuits and dedicated feeds.
Workstation and open-office loads
- Furniture-integrated power on 15A or 20A whips: modular workstation systems from Herman Miller, Steelcase or Teknion connect to poke-through outlets or wall-mounted receptacles.
- Circuit density planning: typically one 20A circuit per six to eight workstations, sized against a 180W-per-workstation baseline plus task lighting.
- Dedicated circuits for monitors, docks and phone chargers: shared with workstation power on the same 20A feed.
- Emergency and legally required lighting: on a separate panel with generator or inverter backup where the building has one.
Server rooms and technology loads
- Dedicated 30-60A single-phase or three-phase 208V circuits for server racks: typically APC, Eaton or Vertiv rack PDUs on redundant feeds.
- Precision cooling equipment: a Liebert, Vertiv or STULZ CRAC unit on 30-50A three-phase, running continuously.
- UPS and battery backup: APC Smart-UPS or Eaton 9PX systems on dedicated circuits, sized to the connected IT load.
- Structured cabling raceway: separate from the power raceway per OESC Section 60, with defined clearances.
Meeting rooms, kitchens and shared amenities
- Meeting room audiovisual power: dedicated 20A circuits for wall displays, ceiling projectors, and floor boxes.
- Pantry or coffee-bar circuits: a 20A dedicated circuit per major appliance (espresso machine, dishwasher, microwave), plus general receptacle circuits.
- Bike lockup or end-of-trip facility circuits: lighting, receptacles, and any charging points for e-bikes.
- Shared print and copy room: dedicated 20A circuits for each floor-standing copier, sized per manufacturer nameplate.
Distribution and subpanels
- Suite-level subpanel per floor or per tenant: a Siemens P1, Square D NQ or Eaton PRL series subpanel with 30-42 breaker positions.
- Riser feeder from the building main service: sized to the tenant load calculation, typically 100-400A per suite.
- Panel labelling and as-built schedules: required for the base building record and any future tenant improvements.
Minimising Downtime During an Office Upgrade: Live Cutover Planning, After-Hours Work, Temporary Power
Office electrical upgrades in occupied space cannot follow the same “power off for the day” approach as a residential upgrade. The scope has to be sequenced around the tenant’s operating hours, critical loads have to stay live, and the base building distribution has to remain available to other tenants.
Cutover planning ahead of the work
- Load inventory and criticality mapping: each circuit tagged as critical (server room, life safety, elevator interlock), semi-critical (workstation power, HVAC), or non-critical (general receptacles, decorative lighting).
- Cutover window agreed with the tenant: typically a weekend, overnight, or a scheduled maintenance window.
- Temporary power scoped for critical loads: a portable generator on a temporary service, or a battery-backed inverter for short-duration cutovers.
- Base building coordination: the building operator’s consent for after-hours work, elevator access for material and equipment, and access to the building electrical room.
After-hours execution
- Physical work outside occupied hours: feeder pulls, subpanel setting, and any work in the ceiling above occupied space happens overnight or on weekends.
- Two-crew sequencing: one crew on the new distribution, one on the cutover, so the live-to-new transition is short.
- After-hours ESA inspection where required: ESA offers scheduled inspection windows outside standard business hours for commercial work.
- Documentation captured as the work progresses: panel schedules, single-line updates, and circuit maps updated in real time.
Live cutover discipline
- One panel at a time: never energize a new panel and leave the old one connected in parallel. The cutover is discrete and documented.
- Critical loads on temporary power during the cutover minute: server rooms and life safety circuits switched last, or maintained on a UPS during the transition.
- Post-cutover verification: every circuit tested, every workstation confirmed powered, and any failure walked back before the tenant returns Monday morning.
Communication with the tenant
- Pre-cutover walkthrough with the office manager and IT lead: identifies critical equipment, hidden dependencies, and any equipment that requires a controlled shutdown.
- Cutover window confirmed in writing: date, time, expected duration, and rollback plan.
- Post-cutover sign-off: the tenant confirms operating status and the final Certificate of Inspection is issued.
