Question

why were the early temples much like a house?

Answer 1

However Temples and Houses are structurally different but here is the answer of your respective quest..

(i) The temple symbolize the community as a whole and was the nucleus around which the city developed.
(ii) It was here that the processing of produce- grain grinding, spinning, weaving was done as in household.
(iii) The rulers of early Mesopotamia's cities were priests.They lived and administered from there. Since temples were used for residential purposes they looked like houses.
(iv) The complex was not only a place of rituals and worship but contained warehouses, workshops and living quarters of artisans...

Hope it helps you...