Desks, chairs, old IT equipment — sized for a commercial clearance, not a household one.
Large skip (8 yd³), scaling with office size
Office clearances are usually bulky rather than heavy — desks, chairs, and partitions take up volume fast even though they're relatively light, so size for space rather than weight.
Computers, monitors and other electrical equipment fall under WEEE regulations, same as household electricals, and need separate recycling rather than going in a general skip.
Business waste in the UK is regulated differently from household waste and usually requires a registered waste carrier and a waste transfer note — check your skip supplier handles this as standard for commercial bookings.