People construct houses with common walls on 2 or even 3 edges of their plot, totally bypassing the Municipal norms.
Municipal Officials too (dubiously?) give permission on some occasions or turn blind eye to the flaunt of rules.
Poor ventilation, feasibility/difficulty in maintenance, safety from fire/theft etc are conveniently forgotten by the land owner.
Only after incidences of fire or collapse of...
more... dilapidated buildings, both parties realise the mistake.
The root cause lies in the land mafia responsible for artificial price rise of land to such an extent that even lifetime savings are many times not sufficient for Indians to own a small piece of land and construct a house. Persons not owning home and in needing of land cannot afford the land price those owning huge tracts of land often have many houses. The disparity of Income distribution is growing worse day by day with top 1-2% owning most of the national assets while middle and poor continue to become poorer.
Digitisation of every square inch of land is not very difficult with present day technology. Linking of digitised along with linkage to Adhaar card and proper legislation/implementation can see land prices falling to affordable levels. Black money can also also be curbed to substantial extent.