I am planning on building a SIPS garden room, and want to build it as close as possible to my existing garden wall. (It will be within UK permitted development rules, so I don't have to leave 1m gap.)
From a practical point of view, though, how do I weatherproof the panels that will be next to the walls? I anticipate leaving a 6-12" gap so they're not right up against the brick so there is some airflow, but it wouldn't be enough room to get into the gap to clad it.
In the diagram below it would be the walls highlighted in blue I'm unsure how to approach:
The red ones are easy - I plan to use suitable damp proof membrane, with battens and cladding over the top.
However, the blue ones have me stumped!