The Housing Ministry has actually issued guidelines to all the local authorities to implement the RWH system (SPAH) for all semi-detached houses,
detached houses and shops middle of 2012. The guideslines can be found here:

http://jkt.kpkt.gov.my/bm/fileupload/Garis-Panduan-SPAH.pdf

Most of the local authorities are still kelam kabut about it but are told to implement it anyway.

IMO, installing RWH system which involves pump which consumes electricity, require maintenance and installatiion cost does not make sense.
It defeats the purpose of 'going green', the objective being to conserve resources.

It is worthwhile only for double storey houses where you have the storage tank on the lst floor level to collect water from the roof and feed by gravity
to the wc's, garden taps, etc.

If you get acid rain in your area (industrial area especially), washing car with the acidic water would be harmful to the car body.

This post has been edited by tehtmc: Jan 5 2013, 11:34 AM