Granny flat under DA with setback restrictions

Hi,

We’re looking to buy a NSW property with a double garage off to one side on the N boundary. It has a 1:8 E downwards slope, so the back has 2m of earth behind it and is being pressured in by a failing retaining wall, but the sides are double brick and seem solid if under pressure.

We’re looking at the potential of adding a granny flat on top. Since the zoning is E4, it would be DA in any case. We would dig out for a new retaining wall behind the garage and plan on a rear staircase entrance.

All setback regulations seem ok, aside from the boundary to the N, which is perhaps 1-2m. Regs say 0.9m for the existing garage, or >2.1m if we went for a cathedral ceiling on the upstairs to get our max 8.5m from ground.

Are the regs applicable regardless of whether permitted development or DA? Given the lack of windows/view towards us, I would hope for little objection if we did propose this. But if the 2.1m rule holds fast, then we’re a bit stuck as we’d otherwise have to take out and move the entire wall/garage.

Many thanks,


Damian

 

How big is the block?

 

2m of soil behind a brick wall will cause it to fail too.

 

About 850m2

 

If it is secondary dwelling permissible, then as long as you adhere to the NSW AH SEPP guidelines on setbacks, you should be able to do it under complying development.

Blocks 450-900 require a 0.9 setback from the side boundary, and varying setback depending on building height from the rear boundary.

 

It’s E4 zoning, so it’ll be DA

 

By reading the bolded line, E4 is similar to R1, have you spoken to a Town Planner or GF builder?

You could give Backyard Grannys (not affiliated) a call and see What they have to say, I've found them very knowledgeable.

If you can get away with a CDC you'll save alot of headache.

 

Thanks! It does sound like I need to look into it a bit more.

However, CDC wouldn’t help even if available as it wouldn’t comply. The side setback is likely <2.1m, which is what we’d need for an 8.5m apex. The rear setback must be 8m (the lesser of 8m and the formula which yields 10.6m), which we have and is fine.

So the question is really the other way around, which is if we do not fit into CDC, can we use DA instead?

Many thanks,


Damian

 

That's a very tall building, I think you'll struggle with a DA, I'm no expert, 8.5m sounds like it could be above the building height limit, that may need to be checked as well.

You should definitely consult with a Town Planner/Certifier/Experienced Granny Flat Builder imo.

 

I will. 8.5m is max under the regs, although I’m thinking the garage + flat + cathedral ceiling may come to 7.5m. It’s inline with the primary residence (2 stories) on the side surrounded by trees and adjacent to the neighbouring plot of a 3 storey house, and 3m lower than the plot behind, so I’d hope it would be reasonably sympathetic to the surrounds.