I'm always intrigued by the Segal method, but it's so closely tied to the sizes of construction materials available at the time and I can't help wondering if anything has changed since.
I've been thinking about doing this, and my main thought is that the insulation standards were probably effectively non-existent at the time, beyond "as few draughts as possible"!
Edit: not sure if these will be geo-blocked, but there are a couple of programmes about that project here:
Build: https://www.channel4.com/programmes/grand-designs/on-demand/...
Revisit 10+ years later: https://www.channel4.com/programmes/grand-designs/on-demand/...