I had a look at this yesterday (Sun 24th June) - I'll have some pictures shortly, but in the meantime here's a link
If you want to see it for yourself, it's right by St Wendreda's church (very fine carved roof beams) in the town of March, Cambridgeshire.
Anyway, my impressions were quite an attractive design, on a very small plot. Quite a large area of photovoltaics on the roof (maybe 5 sq m.). Roof is slate and these tiles match the slates very closely, very unobtrusive, mostly a change from matt grey to a glossy grey.
I couldn't see the high levels of insulation as the build is near finished. What could be seen on the lower floor and amongst the builders rubble was 50mm Kingspan. Lower half had just had mesh attached ready for rendering. Upper half has chestnut cladding, and very neatly done too.
Windows looked to be pine timber framed quality units, though no large areas of South facing glass for solar gain. No apparent sign of solar water heating.
I haven't seen the earlier stages of construction, though the picture on my link above shows blockwork, certainly up to first floor windows. There's a small amount of exposed lower floor brickwork around doors and windows.