The house is a detached bungalow, late 1960s build, with the length of
the roof running from front to back so that the gutters run also front
to back. Similar to
https://st.hzcdn.com/fimgs/eca2b33a0...27-b0-p0--.jpg
when looking from the front.

A brick garage is on the left hand side and extends a few feet (enough
for a side door plus a bit). The roof is felted - see other post re
moss problems.

Water is getting in at the end of the bungalow and around the side
door.

I'm not fully up with the bulding terms but the verge under the last
two edge tiles are cracked, and the area underneath and therefore to
around the top of the garage is coming away. It's a sort of render.
The best I can do to explain it is that it is similar to the
unlabelled black area under the verge at
https://www.nationalplastics.co.uk/b...nedbullets.jpg

Tips, clues how to diagnose and how to repair needed.

--
AnthonyL

Why ever wait to finish a job before starting the next?