Browne Smith Baker's Carbon Challenge scheme

We've started talking to one of our customers, Pickering & Ferens Homes about developing a standard house type specification. I think this is a great opportunity for us to find out how much a zero carbon Code Level 6 home will cost. I went to a presentation  by local architects Browne smith Baker a few weeks ago and was surprised at how cost efficiently they delivered it - would be interesting to know if anyone has achieved similar results on smaller schemes