If you spend more than your company capital expenditure threshold on an item for the office, you have to take the value of that purchase as an asset. Check out the explanation on Computer Hardware for further info regarding high value purchases of assets.
Chairs or Desks
Any other item of expensive furniture around the office
What's not included
Electronics and other hardware should be categorised in to Computer Equipment.
Less valuable items can be categorised directly against the expense, for things such as a keyboard or a mouse against Office Supplies for example.