It all depends what you want with the house for? Colombo district is small but do not get houses near the sea, it is very humid , very hot and every thing gets rusted. Get houses by river which area is not poluted not near beira lake. Colombo 2 is being fully demolished. Only expenisve flats are being buit in Colombo 2.Most of firms are in Colombo 1 and 2. Take houses in Colombo inland but not in Kelaniya or Wellampitaya where there is flood all the time. Methotamulla stinks. Rajagiriya and Borrella with full of traffic. Colombo 3,4,6 only good for people who want to buy from shopping malls, very expensive food stuff, and full of traffic ,lots of good institutes to study.Dematagoda full of pot holes , cinamon gardens very expensive remote from all the shops.Matakuliya full of dengue mosquitos.Maligawtha and maradana one way street. Most of other areas of colombo is very conjested. Grandpass,Kotahena parts of bluemendal road,High level road are very good places.Dehiwala and Mount Lavinia are not part of Colombo.