Holland Park/Shepard's Bush
Is actually a very posh area. Well Holland Park mostly always was, with great Victorian homes built out from the park, and since Jean Hardcastle lives just across from the park, you can imagine her house would be worth a bob or two.
Funny scene in "AbFab" when Patsy Stone is being interviewed by "Hello Magazine" at Ed's house and the reported says "where am I", "what is this area"? "Shepard's Bush?. Edina appears screaming "Holland Park, Holland Park"! She futher goes on to say it is the "rich heartland of Holland Park".
As for Jean HardCastle's townhouse kitchen, it is on the same floor as the livingroom and dining room, just down the hall. Indeed if one walks in the front door it is right down the way past the stairs.
If the house is old as the area, it could be at one time the kitchen was located down stairs, but moved up to the first floor as servantless housekeeping took over. Many people who purchase NYC townhouses (Brownstones), lament having the original kitchens in the basement as it means trudging up and down several flights of stairs all day long.
Wealthy familes with live in help of course rarely if ever went down into the kitchens, since that was the servants domain. When developers began to build middleclass suburb houses in and around London around 1900, the put the kitchen on the main floor (as in 1900 House), since it was a given that these homes wouldn't have the old arrangement of full time servants.
en.wikipedia.org