Our carpenter balances on his ladder, and a saw buzz-screams into the wooden beam, sending a flock of birds fluttering away to the quiet of a neighbouring garden.
They’re cutting out a small rectangular piece, into which the rafters will be slotted. An equivalent small piece is cut into each rafter, so that they will fit snuggly into each other. It’s painstaking millimetre-work, involving much measuring with his set square and water-level to get it right.