What you need to know about granny flats

What you need to know about granny flats
By Scott Bentley


What you need to know about granny flats

Granny flats, secondary dwelling – they can be a great idea whether for extended family or adult children needing some space.


Before you make the decision to build a secondary dwelling, or buy a property where there already is one, there are a few things to consider, or take advice about.

For a start: how is it defined? A simple sleepout, with no amenities, reliant on the main house and less than 10 sq metres, can probably be built without a building consent, although it will need to meet other requirements.

However, anything else that is self-contained, with bathroom and cooking facilities as well needs to have a building consent and resource consent. This is one thing that, if you’re thinking of buying a property with a minor dwelling on it, it pays to check there has been a consent issued so you don’t land with extra costs.

The Building Act 2004 provides all the rules around building a separate granny flat, as well as regulations in the Building Code, plus here, the District Plan. Sounds rather complicated but the council is there to provide all the technical advice you need.

Some pointers :
  • Your minor dwelling will have to comply with the minimum and maximum size set down in the rules.
  • Your property will also need to be above a minimum size and zoned or converted for a granny flat.
  • It will need to be a single storey.
  • A minimum distance from the main dwelling will be required. 
  • Think about services – water, wastewater, electricity. If you’re in a rural area, you’ll need potable water supply and a sewage disposal system available.
At first glance, it looks a bit daunting, but in fact all it takes is a conversation with a council advisor.  Here at First National Marlborough, we are also more than happy to help if you’re thinking of buying a property and adding a minor dwelling.