Hi DP
When I've quoted for large offices, I've quoted in two different ways. For bonnet cleaning I've quoted on day rate, and for all other systems, ie HWE Host & Dry Fusion I always quote on Sq.M. For day rate, I include my own labour costs, other labour & sub-contractors, materials, travelling including time travelled if not local etc. etc. When I have the final figure I will then
at least double this to give profit for the business and to cover normal overheads. Quite often it has been plus 200% or even more. HWE would have a larger premium for, say, 2 days work than the same time spent elsewhere on a bonnet.
On a job like this I would break down the task into it's component processes such as: To pile lift vacuum, pre-condition etc. etc. Carpets to: Board Room, Accountants Office and so on. I would not normally break down the cost to individual areas, just a total at the bottom. My perception is that the prospect will then have a feel for what's involved and the areas sound more than just "1st floor carpets". Check your liability insurance. For example, you may have sufficient Public Liability, but the Treatments Risk may be as low as £5k.
Subject to agreement with the prospect, I would include:
13amp power sockets, hot water and WC(s) for soiled water to be made available. Employees personal effects and any ongoing files etc to be removed from the floor. Fixtures, furnishings etc. will not be moved for cleaning purposes. It is not uncommon in offices for power sockets to be less than 13amps so are of no use to us. Check first so you don't blow fuses.
Good luck
Safe and happy cleaning

Ken