Would you build a granny-flat on your investment property?

The rules have been becoming more flexible in Perth regarding secondary dwellings and the strategy has been popular in Sydney for some time, but is it a strategy that you as an investor would undertake?

Recently, a property industry expert has come out against them saying that they are worse investments than vending machines,  however we have also been told that they are a great value adding technique.

"A property which recently added a granny-flat in addition to the house was able to achieve a consolidated income of $900 per week," said founder of Australian Mortgage Options, Robert Projeski.