I should explain ‘drainage’ more. Councils (in AUS) regulate ‘waste water’ from homes, its treatment and its release into environment and also ‘rain and flood’ drainage. This means that modifications or renovations do not create drainage issues to neighbors and others down-streams.

In Thailand, waste water from one home can cause issues elsewhere – uncontrolled; land-filling can be done (and cause flooding on neighboring homes) – uncontrolled.Water release (eg. by watering sprinklers, cleaning and washing ) from one home can compromise foundational and/or structural stability of near-by buildings – uncontrolled. There are more drainage issues that are uncontrolled in Thailand.