Party wall notice

[duckers26]

I am going to be building a rear extension to a semi detached property. I understand that there are two types of notice that can be served: a party wall notice or one for building within 3 metres of a neighbouring property.

On both sides the extension is set back from the boundary by around 45cm, and the attached house has a similar extension, again set back a similar distance from our boundary.

The other neighbour who are not attached actually have a garage which is right up to the boundary and forms the wall between the two properties for about 3 metres.

My understanding from reading the planning portal is that I should serve a party wall notice to my joined neighbours and a 3 metre notice to those that are not joined. Is this correct or might it be a party wall notice to them both?

Thanks

[Johnniem]

This is made complicated by the fact that there are no drawings attached to your post. Please feel free to pm me and I can arrange to speak directly to you. I am a party wall surveyor and can point you in the right direction. It can get costly!