Office wiring isn't more complex than a home installation so much as it involves more equipment running at once in a smaller footprint: computers, monitors, office equipment, network gear, air conditioners. Without planning outlets, data points, and load in advance, six months after a renovation the office ends up living on extension cords and power strips.
Here's where to start planning so office electrics don't become a bottleneck later.
Where to start planning
The first step isn't picking outlets — it's a seating plan: how many workstations, where printers and office equipment sit, where the server room or equipment rack goes, where the meeting rooms and reception are. Power and data point counts get calculated from that plan, not the other way around.
The second step is a list of equipment with rough power draw: computers, monitors, air conditioners, a coffee machine, a kettle in the kitchen, office equipment. That's the basis for calculating panel load and splitting it into circuits.
Outlets and data points at workstations
A single workstation with a computer typically needs at least 2-3 power outlets: for the PC tower, the monitor, and some spare capacity for a phone charger or extra device. If a workstation is set up for two monitors or extra equipment, plan for more — redoing a power point after renovation costs more than installing one spare outlet upfront.
Data points (network or wired phone) are planned separately, usually in the same duct or close to the power outlets, but with proper spacing kept between mains and low-voltage cable to avoid interference on the network.
Powering the server room or equipment rack
The server room or network equipment cabinet is the most demanding area of an office electrically. What matters here: a dedicated line from the panel, separate from workstation outlets (so an overload elsewhere on the floor doesn't take the server down), and typically a UPS that keeps the equipment running briefly during an outage and allows a clean shutdown without data loss.
If the server room holds active network gear or several pieces of equipment, it's worth calculating the total load in advance and sizing outlets and the breaker with headroom rather than the bare minimum — server equipment tends to get added to over time, not scaled back.
Calculating the load of office equipment
A computer with a monitor typically draws relatively little — around 150-300 W — and doesn't create much load on its own. Air conditioners, an electric kettle, a microwave, and a kitchen coffee machine draw noticeably more — appliances like these are actually the most common cause of overloaded office wiring when they share a circuit with workstations.
| Equipment | Approximate power draw |
|---|---|
| Computer with monitor | 150-300 W |
| Laser printer/MFP | 300-800 W (at peak printing) |
| Air conditioner (split system) | 1-2.5 kW |
| Electric kettle | 1.5-2.5 kW |
| Microwave | 1-1.5 kW |
| Coffee machine | 1-1.5 kW |
This table shows why it's worth putting the office kitchen area on its own dedicated circuit — or two to three circuits if there's a lot of equipment.
The office panel: circuits and breakers
An office panel is usually split into at least several circuits: workstations and lighting by zone, a dedicated circuit for the server room/rack, a dedicated circuit for the kitchen and appliances, a dedicated circuit for air conditioning. That split means an overload or short circuit in one area doesn't cut power to the whole office.
Circuits with outlets, especially in the kitchen and areas with electrical appliances, should have an RCD (residual current device) — it cuts power on a current leak and reduces the risk of electric shock. An RCD makes sense on computer and network circuits too, but sizing breakers and choosing types is best left to an electrician at the panel design stage, based on the office's actual total load.
Common mistakes in office electrical work
- Outlets planned to fit the current seating exactly — the first office reshuffle brings out the extension cords.
- Kitchen appliances and workstations sharing one circuit — a kettle or microwave trips the breaker and cuts power to computers.
- The server room running off a shared circuit with no dedicated line and no UPS — a voltage dip causes equipment to restart improperly.
- Panel sizing done with no headroom for future staff growth or additional equipment.
It's worth designing office wiring together with an electrician during the renovation stage — a seating plan and equipment list are all that's needed to start calculating the panel and outlet layout.