Granny Flats

Granny flats are becoming an increasingly popular way of helping adult children with affordable housing, providing care for older parents or others in need, or for simply adding an extra income stream from rental.

We have been designing quite a few of these recently, and they present some great opportunities.

NSW legislation allows either attached or detached dwellings to be added to most suburban and semi-rural properties.

The general rule is a maximum of 60 square metres, although if the principle dwelling is more than 300 square metres, the granny flat can be increased to 20% of the main house size. For example, if your existing house is 400 square metres, the granny flat can be 20% of this, which would be 80 square metres.

Council rules with regard to maximum site coverage still need to be adhered to - most Councils have a limit of either 40% or 50% of the site which can be built upon - the remainder needs to be left free for landscaping and private open space. There are also various setback rules from boundaries which need to be maintained.  

The area limit applies to the enclosed area, with decks and verandahs generally possible in addition to this area. A garage or carport is not mandatory but, if provided, is also additional to the maximum area.

A market for granny flats has opened up, with lots of prefabricated options being offered. These are the cheapest options, of course, but with limited space you want to be sure you are getting the most useable and functional design possible. Every site is different, and an individually designed solution will always be the best. We design secondary dwellings to fit the site, the terrain, the views, climate, energy useage, and to be a good looking addition to your property.

Proper advice is critical when adding onto or converting part of the existing house for a secondary dwelling, as there are strict rules in the Building Codes regarding fire ratings and acoustic separation. These can become critical to the viability of the project.

Give us a call if you would like to discuss your options!