I'm off to appraise housing development (6)
I believe the answer is:
estate
'housing development' is the definition.
(housing estate)
'i'm off to appraise' is the wordplay.
'off' indicates named letters should be taken away.
'to appraise' becomes 'estimate' (appraise can mean to estimate something's value).
'estimate' with 'im' taken out is 'ESTATE'.
(Other definitions for estate that I've seen before include "Family land" , "all the deceased owned" , "Car; landed property" , "The whole of one's worldly goods" , "A group of buildings built together in one development" .)