Been ages since update! That doesnt mean nothing has been happening!
Lead flashing to roof lights now in place with fleese natting betewwm lead and glass to mitigate risk of thefmal shock
Insulation to inside complete
Drains for utility room and shower room installed.
Slightly unorthodox testing, couldnt seal both ends as no easy access to existing vent stack , so stopped up in manhole before the road and filled system with water. After 1 hour the water had not dropped even a millimetre so recon all seals are water tight!