As the photos, suggest, this house is in a spectacular location with some really great views of the Bosphorus. Buyukdere, the Istanbul suburb where it is located, is a relatively unfashionable area but I felt it has a lot of charm and being next to the Bosphorus is always good. There is a ferry stop here and you can get all the way to Eminonu in the old town for around 40p (you'll need an Istanbul card - a worthwhile investment for buses and underground too)! The journey is also spectacular. Sariyer, a larger area with some nice restaurants, cafes, pubs and a further ferry service to the less visited northern Bosphorus, is about 15 minutes' walk up the road. Other transport links into town include the buses and a minibus service into Besiktas (you'll probably need at least some Turkish to take this on). Or you can get a taxi to the end of the Metro line (Haciosman) for about 20-25 lira (£3-4). On the way back taxis will need help finding the house, though! Or you can simply walk up the (very steep) steps to the house.
The house is really very impressive (and very clean), with some really great double rooms; the kitchen is well-equipped too and we really liked the patio. The only lack we felt was a lounge or similar room downstairs. And it gets quite warm in the house in summer - there are fans but no aircon.
Mesut is a kindly and helpful host (it helps if you can speak Turkish or German) and stays out of the way but is also happy to have a chat too. He helped us set up the bbq and proved expert at making a good fire. He helped us order taxis for the airport too.
In short we had a great stay, facilitated by Mesut's sensitive and helpful hosting. Would love to go back.