In St Paul's (EC4) the split is 98% flats to 2% houses over 4,914 households, and the stock is post-war.
Because 48% of St Paul's is privately rented and 15% socially rented, a lot of EC4 work is agreed with a landlord or managing agent rather than the person opening the door.
Walls are with metal stud partitions between rooms, over dot-and-dab plasterboard over blockwork, the pattern behind 4,914 households inside the EC4 neighbourhood, so the fixing that matters in St Paul's is chosen on site — the usual failure here is short screws that grip only the board and slowly lever it off the dabs, as the St Paul's stock goes, and with 48% of homes here privately rented, it sets the booking date as often as the job does.
St Paul's 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 — cathedral precinct, One New Change shopping and the streets running down to the Millennium Bridge — which is why a EC4 quote is not a City of London average.
Pedestrianised zones and camera-enforced streets; loading needs a permit from the Corporation. Nearest station is St Paul's (Central), and one technician with a portable extraction machine and air mover on a single household booking; two technicians on HMO, student accommodation and serviced-apartment rounds where six or more mattresses are cleaned in a day.