Demolishing 1 of 2 detached garages

[Knock-knock]

Hello,

I've recently moved in to a property and I am planning on replacing my garage with an extension.
My garage is linked to my house but detached from my neighbours. My neighbours garage is completely detached. However, the two garages are very close to one another. They both have pitched roofs and share a gutter to stop water running down between the two walls. It is clear that over time the walls have been weakened by overflowing water that has potentially deteriorated the foundations of both garages (if there even are any!)

I'm concerned that if I remove my garage for an extension this may unstabalise my neighbours garage.

As the garages are detached from one another and sit on our own boundaries, who would be responsible for ensuring that the neighbours garage is structurally sound in the event of me demolishing my garage, digging new foundations and extending my house? If they shared a wall I assume it would be on me but unsure in this situation.

I will of course have a structural engineer check it all out however just trying to get my head around what lies ahead.
Thank you in advance for your advice.

 

[Notch7]

I wonder if the garages have a shared foundation?
if built at the same time, it would make sense.

garages are sometimes built on a raft


Since your extensions foundation will be deeper than the neighbours garage you will need a party wall notice to be sent (I think).

 

[^woody^]

If the garages are separate then I can't see how your garage affects the neighbouring garage structurally.

You are responsible for allowing the neighbours roof to drain properly regardless.

If the PW Act applies, which is dependent on the wall location, then the preservation of neighbours walls and property generally is included in any Award.