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.
44% of households rent privately and 28% own, which is why bath and shower screen fitting demand here peaks around tenancy changeovers and completion dates.
Expect dot-and-dab plasterboard over blockwork in SW1, with metal stud partitions between rooms — which is what a 95% flat share across the ONS neighbourhood covering Westminster and Whitehall actually produces behind the plaster in SW1. That is why fixings are picked in the room rather than off a van shelf, and why short screws that grip only the board and slowly lever it off the dabs on these streets — 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.
Getting to the door matters as much as the job: security cordons, camera-controlled streets and pre-notified vehicle access on many roads. Westminster (Circle, District, Jubilee) is the nearest station, and one fitter for a pivot or fixed screen; two for sliding and bi-fold enclosures and any wet-room panel over 190cm, which is awkward to hold plumb alone.