Dissertations / Dissertation topics-in built environment subjects [4]

hi friends,
As a part of MSC ,I have to do a dissertation in built environment topics.
As I am doing my MSC in quantity surveying can any one suggest a nice topic.
what i have in my mind is a comparative study on cost analysis of traditional construction and sustainable costruction .Can any one provide any suggestion this topic or any other topic.

regards,
Cicin