All the houses are located at Willesden Green, inside London zone 2. To not take a risk of getting lost before you get there, you can check the best routes here, departing from the most known London airports.
If you decide to catch a minicab, you can find the aproximate journey prices below every route, which can be booked by me, before you arrive.
It is always a good ideia to walk around with a tube map
copy in your pocket, and if you don't have one, you can download
it clicking here.