In Belgravia (SW1) the split is 92% flats to 8% houses over 3,844 households, and the stock is post-war.
Because 30% of Belgravia is privately rented and 48% socially rented, a lot of SW1 work is agreed with a landlord or managing agent rather than the person opening the door.
Belgravia substrates run to precast concrete panels and dense blockwork in SW1, often with surface conduit, measured on the walk in from Sloane Square (Circle, District) rather than assumed from a map. Nothing is drilled until the wall has been sounded, because Belgravia gives us drilling blind into a panel with reinforcement or a buried cable behind it, the reality on the streets around Eaton Square is the mistake that costs a SW1 customer twice.
Belgravia sits inside the Congestion Charge zone as well as ULEZ, so both are itemised on the quote rather than absorbed into an hourly rate. What shapes the job more is the neighbourhood itself — grosvenor estate stucco, embassies and cobbled mews behind Eaton Square — which is why a SW1 quote is not a Westminster average.
Estate parking rules, mews arches with height limits and listed staircases requiring protection. Nearest station is Sloane Square (Circle, District), and one technician for a private path; two where a communal walkway has to stay open to residents while the work is done, so one can manage access while the other washes.