Does a granny flat add value to your property?

A granny flat usually adds value, but not automatically and not always by the amount it cost. The value comes from 2 separate things: the income it can produce, and what a future buyer thinks it is worth to them. Those 2 can point in different directions, and which one dominates depends on your suburb and your buyer.

This article covers how to work it out for your property rather than quoting a number that was true for someone else’s.

A granny flat that can be rented produces income, and income is what valuers and investors respond to. For an investor buyer, a property producing 2 rents is straightforwardly worth more than the same property producing one.

This is the more reliable of the 2, because it is measurable. You can look up what comparable granny flats rent for in your suburb today.

This one is less predictable, because it depends on who is buying.

In a suburb full of young families who want lawn, a granny flat covering half the backyard can narrow your buyer pool. In a suburb with lots of multi-generational households or investors, it can widen it considerably.

The one that matters most is approval status, and it is not close.

An unapproved secondary dwelling is a liability, not an asset.

When you sell, it has to be disclosed. A buyer’s solicitor will find it. It can affect finance, because a lender may not value an unapproved structure or may refuse the loan. Insurance can be affected. Council can require it to be brought into compliance or removed.

This is why the approval pathway is worth doing properly even when it is slower. A fully approved granny flat with an occupation certificate is an asset on the title. An unapproved one is a problem you have to solve before you can sell.

Nobody can tell you the number from a blog post. Here is how to find it.

Step 1: Find the rental comparison. Search current listings for granny flats and one or two bedroom units in your suburb. Not last year, now. That gives you a realistic weekly rent.

Step 2: Find the sales comparison. Ask a local agent what properties with an approved granny flat have sold for in your suburb compared to similar properties without one. Agents know this and will usually tell you.

Step 3: Get your actual build cost. Not a market range, a quote for your block including site costs and approvals.

Step 4: Compare. You now have 3 real numbers instead of 3 assumptions.

Step 5: Ask the people whose job it is. A valuer can tell you the valuation effect. An accountant can tell you the tax position. Both are worth the fee before you spend 6 figures.

The honest position is this. A well-designed, fully approved granny flat on a block that still has usable yard, in a suburb where people want rental income or room for family, generally adds value and generally produces income that pays back over time.

A poorly positioned one that swallows the backyard, on a block in a suburb where buyers want lawn, may add less than it cost.

Anyone promising you a specific percentage return without seeing your block and your suburb is guessing.