Census 2021 puts Westminster and Whitehall at 3,927 households with a median age of 35.1. The period conversion stock is renter-heavy, which is why 5% houses and 95% flats need different handling in SW1.
Private renting sits at 44% and owner-occupation at 28%; the first group books shed assembly at short notice, the second plans it.
Expect dot-and-dab plasterboard over blockwork; locally that also means with metal stud partitions between rooms — the reality on the streets around The Palace of Westminster behind the plaster in SW1. That is why fixings are picked in the room rather than off a van shelf, and why in SW1, short screws that grip only the board and slowly lever it off the dabs — which is why Westminster City Council kerb rules get settled before the van is loaded is the fault we are called back to undo.
Two streets can behave very differently in Westminster and Whitehall: government quarter around Parliament Square, Whitehall and Smith Square. The quote reflects the street the job is actually on. Westminster and Whitehall sits inside the Congestion Charge zone as well as ULEZ, so both are itemised on the quote rather than absorbed into an hourly rate.
On access, security cordons, camera-controlled streets and pre-notified vehicle access on many roads — one reason one fitter for a small shed on a ready base; two for anything over 8x6ft or where roof panels need lifting together. Fitters travelling in use Westminster (Circle, District, Jubilee).