Office Interior Design: Density, Acoustics and Fit-Out Reality
Office interiors are judged on a spreadsheet and experienced on a Tuesday afternoon. The projects that work get the boring numbers right first — how many people per floor, how far to a meeting room, how loud it gets by 3 pm.
Space per person
A comfortable open-plan workstation is 1200 x 600 mm with 900 mm of circulation behind. Compressing to 1050 mm width is common and workable; below that, monitors start competing with elbows. Plan around 70–110 sq ft per person including circulation and support spaces — the low end is dense, the high end is comfortable.
Meeting rooms: the usual miscalculation
Most offices build too few small rooms and too many large ones. A useful ratio is one enclosed space per 8–10 people, weighted heavily towards 2–4 person rooms and phone booths. The 12-seat boardroom gets used twice a week; the two-person room is occupied all day.
Acoustics is the line item that gets cut
Open plan plus hard floors plus a glass facade equals a room where nobody can concentrate. The fixes are unglamorous: acoustic ceiling tiles or baffles, carpet or acoustic vinyl in dense zones, upholstered or perforated panels on at least one long wall, and enclosed phone booths so calls leave the floor. Budget for this at the start — retrofitting acoustics into a finished office is expensive and looks it.
Lighting and screens
Aim for around 300–500 lux at desk level with low-glare fittings. The common failure is bright downlights directly above screens, which reflect straight into the user's eyes. Position rows of light between desk rows rather than over them, and get daylight to the desks rather than the cabins — glass-fronted cabins on the facade wall borrow daylight without stealing it.
Services and coordination
Ceiling voids carry HVAC, sprinklers, electrical, data and lighting. Coordinating those before the ceiling grid is set is what separates a smooth fit-out from a site full of rework. Raised floors or floor boxes for power and data cost more upfront and save every time the layout changes.
Leased space changes the maths
On a five-year lease, spend on what you can take with you — furniture, partitions, loose fittings — and negotiate hard on what stays. Check the landlord's fit-out guidelines and reinstatement clause before you design, not after. Many designs get redrawn because the base build forbids a core drill or a facade fixing.
Phasing an occupied office
If the team stays in during the work, phase it: complete one zone, move people in, then start the next. Noisy and dusty activity belongs to evenings and weekends, written into the contract rather than negotiated weekly.