3 Tips for Granny Flat Designs Sydney

In this blog post, we will provide 3 tips on granny flat designs Sydney and NSW.  iBuild offers more than 10 granny flat designs for you to choose from.  You could bring your own design and we can provide customised design for you.


  • For CDC with a Private Certifier, the external dimensions must be 60m2 or less.  Even if there is a small variation, it will be a problem.
Granny Flat Designs Sydney :: Parramatta


The key is above existing ground – The lowest point of existing ground is the measuring point – To the highest point of the roof peak.

  • The maximum height from the existing ground to roof tip must be no more than 3.8m.  If it is higher, it will affect the setback.  On blocks less than 900m2 (which is most of the blocks), this could make the setback too big to fit the granny flat on the block.
  • When a floor footing system is used, it would often raise the height by 400-500 mm.
  • In the event that the roof tip exceeds the the height of 3.8m, you can lower the roof pitch so as to lower the height.

Setback Calculations Notes

Building to be maximum 3.8m above existing ground

  • Setbacks – Determined firstly by block size and width at building line of existing house.
  • Below 900sqm and below 18m wide, setback = 0.9m for Side and 3m for rear.
  • If block is 18m + wide, setback = 1.5m for side and 3m for rear.
  • If Big block 900sqm + and 24m + wide, new set of rules.

Building exceeds the maximum 3.8m above existing

  • Side setback: Divide height above 3.8m by 4 and add this figure to side setback.
  • Example: 4.8m overall height from existing ground = 1m over.   Add 0.25m to side setback = 1.15m Side setback
  • Rear Setback: Multiply height above 3.8m by 3 and add to rear setback.
  • Example: 4.8m overall height from existing ground = 1m over.  Add 3.0m to rear setback = 6m rear setback


Many granny flat designs use a lot of space for a laundry.  Instead, you could just use a small area with a sliding door to cover the facilities such as this for example.  

You May Also Be Interested In

Compare listings