Peak day, not average
If average attendance is 60% but Tuesday is 85%, you need to size for Tuesday. Sizing for the average creates a peak-day pinch point that drives people away from the office on the day you most want them there — usually the day with the most collaboration value. The right starting question is not 'what is our average?' but 'what is our 85th-percentile day?' Size for that, plus a small buffer, and the office works on every day people come in.
Desk-sharing ratios in practice
UK hybrid teams typically operate at 0.7–0.85 desks per employee. Below 0.7 and peak-day discomfort sets in. Above 0.85 and you're paying for empty desks. Booking data is the only reliable input to this calculation — guesswork and survey data both overestimate office attendance by 15–25%. Run 3–6 months of booking data before committing to a ratio, and re-validate annually as the working pattern evolves.
Don't forget parking and rooms
Parking and meeting-room demand are often the binding constraint, not desks. Plan all three together. A site optimised for desks but underspec'd for rooms pushes people back to Zoom from their hot desk, which destroys the case for being in the office at all. The hierarchy of constraints in most hybrid offices is: meeting rooms > parking > desks. Plan the room mix and parking capacity first, and the desk count will fall out as a derivative.
Room mix by size
The most common room-mix mistake is over-providing large rooms and under-providing small ones. Hybrid meetings are smaller on average than pre-pandemic meetings — more 2–4 person calls, fewer 12-person workshops. Aim for a mix weighted toward 2–4 person and 6–8 person rooms, with a small number of larger rooms for set-piece events. Phone booths for one-person video calls are no longer optional; budget one per 8–12 employees.
Flex days and the weekly rhythm
Most hybrid offices have a clear weekly rhythm: Tuesday-to-Thursday peak, Monday and Friday quieter. Capacity planning should align with the rhythm rather than trying to flatten it. Spreading attendance across the week sounds appealing but rarely works in practice — people come in on the days their collaborators come in, and management edicts to flatten the curve drive resentment without changing behaviour. Plan for the peak, accept the quieter days, and use the quieter days for cleaning, maintenance and quiet-focus seating.
What changes as the team grows
A 20-person hybrid team can manage with informal booking. A 200-person team cannot. The system needs to scale with the headcount, and the ratios shift slightly as the team grows — bigger teams need more meeting capacity per head, more phone booths and more parking flex. Re-plan capacity at every 50% headcount change, not just at lease renewal.
When to break the lease
If utilisation has run below 60% on the peak day for two consecutive quarters, the lease is too big and the operating cost is leaking. The right answer is usually to sublet or surrender a floor, not to try to fill the existing space with mandates. Mandates produce short-term spikes and long-term attrition; right-sizing produces sustainable operating cost.
Right-sizing a hybrid office is a multi-variable problem with one good answer per site. Measure, model, then commit — and revisit annually as the working pattern evolves.