[/FONT]I have my doubts whether it (the agrahaaram or row-houses style of living) had anything to do with "hindu practice of architecture". We usually find such agrahaarams in places where the king or the local ruler, in the olden days, brought a group of brahmin families and settled them. Since the land would have been farmland or garden land before such a settlement decision was taken by the king, most probably the farming class would have been grieved if each such brahmin household were given a good plot of 10 cents or so; additionally, it was customary for the kings to exempt these agrahaaram lands and houses from all types of taxes and levies, in order to make it a complete "daanam" to brahmins. Hence, the efforts could have been to settle these brahmins in the bare minimum of land and since, the know-how for building multi-storied buildings was not known in those times, they arranged (packed) the houses tightly in the horizontal direction, instead of in the vertical direction as of today.
The temple at the eastern end, usually a Siva temple, possibly added to the auspiciousness and convenience of temple worship of the inmates and the word agra-haaram could also have meant the foremost garland, implying that the highest caste people only lived there. Even in my mother's youth, NBs could not enter into any agrahaaram; the NB vegetable vendors, reportedly, brought their vegetables and after placing them on the non-temple edge of the street, used to make a special sound and then the brahmin ladies used to go with a chombu of water, sprinkle on the vegetables, pick their needs and after the prices were bargained, keep the money (coins) on the ground and not give to the vendor. All this time the vendors had to stand a respectable distance away from their merchandise and only call out the prices, rates, etc. There was no weighing and prices were always on eye-estimate basis (கண் திட்டம்).
Similar street houses were there for weavers, potters, blacksmiths etc., but those were simply called streets (தெரு). Scholars in Tamil may debate whether this தெரு system is reflected in ancient Sanga literature. In any case, this தெரு, street or agrahaaram system is indigenous to the south only (no such thing in North India) and so, may be, we can call it a Dravidian architecture.[/COLOR][/SIZE]