Party Wall Agreements

[Bazile]

If you are building an extension across the rear of your house ( semi-detached houses ) . Do you need a party wall agreement both from the house that you are attached to and the house on the other side as well ?

The house that's attached to already has a conservatory and the other house already has an extension 

[Buenchico]

This might help:
https://www.fmb.org.uk/find-a-builder/ultimate-guides-to-home-renovation/party-wall-agreements-what-you-need-to-know.html

[Bazile]

Thanks Chris 

Have you got some picture examples of what constitutes party walls please ?

[Buenchico]

See the diagrams in Part 1, Section 3 ("What is a party wall?") of this detailed information document:
https://www.gov.uk/government/publications/preventing-and-resolving-disputes-in-relation-to-party-walls/the-party-wall-etc-act-1996-explanatory-booklet