Subdivide and build new home at rear vs no sub/d but build Granny Flat

Is it worth investing in a sub-dividable or already subdivided home, then building a new home behind/side for instant equity increase as well as good yields and handy depreciation VS buying a simple IP that allows a granny flat at rear, saving outgoings, build time/costs then moving onto another property.

I'm considering purchasing another IP for a granny flat build at rear, and recently came across a buyers agent who built a new home at rear. His figures are similar to what I've used so it's got me thinking, the increase in equity is really handy especially for someone like myself who is in the accumulating phase - granted of course the build happens fast and no major issues arise. For this example I've gone with a property already split into 2 lots, and house cost/rents from Logan and Ipswich regions.

Option 1 Granny Flat Option 2 Sub/D
House 250K House 250K
Granny Flat 120K New house 220K
Total Costs 370K Total Costs 470K
Current Valuation 370K Current Val 600K
Combined rent $480 p/w Combined rent $620 p/w
Equity 0 Equity 130K
Yield 6.7% Yield 6.8%

CBA broker told me if I were to build a granny flat on the back of my property they would value it as the exact cost of the granny flat on top of the house value, no increase in equity on top even with increase in rent - Hence my figures. Depreciation on new Granny flat 1st yr approx $5000, new home minimum of $7000 pr yr declining.

 

You're assuming a subdivisable property would be the same price as one that is only allows GFs though.

All other things being equal they wouldn't be the same price. That's why it looks like an easy choice.

 

In your new house scenario I can't see any allowance for subdivision fees such as council services contribution, surveying, town planner etc?

 

There is actually many lots in said area's already on 2 titles under 300K. I looked at one last week for 257K but the house needed too much reno $ so I didn't put an offer in.