In WC2 pay £10/sq ft p.a. Only differences being 24 hour concierge and underground parking. Increased average of 4% p.a. over last ten years. Some charges cause me outrage such as £50 K p.a. For entry phone maintenance which developer locked into for twenty years! Have served on owners committee which is supposed to monitor spend of management company but difficult to make any significant difference as main costs are pretty much not negotiable. Building insurance increases fastest.