Some interesting sidelines I'm finding along the way, they may promote wood but:If a biomass system were used instead of gas, its carbon emissions would be about 30% less. The biomass system may be less efficient and use about 50% more energy than gas. Review of changes
I hope to goodness I am wrong on this one, as it would be the most draconian new measure I am aware of and possibly make these new houses almost unsaleable. Here are the regulation summaries direct from the government site:
27. For new buildings, the Government has committed to introduce zero carbon standards from 2016 (homes) and 2019 (non-domestic) for all new buildings. The proposed 2013 changes take the next step towards those zero carbon standards, by tightening the carbon dioxide (CO2) targets for
new buildings and introducing a specific energy efficiency target for new homes.
28 ...and are likely to require building-integrated renewable energy generation technologies (such as solar panels)...
Ove Arup haven't referred to the rule directly on their handout for compliance, but lists the alternatives as:
 Application of „flexible demand‟ systems (supporting demand side management)
 Use of grid-injected bio-methane linked to the site by Green Gas Certificates
 Installation of communal heat accumulator (site based heat storage)
 Home electric vehicle charging
 Electricity storage for the home (to store electricity generated from PV panels)
(note the absence of non 'Green Gas')
The sources appear to be: The legislation consisted of the European Energy Performance Building Directive, existing building regulations and the Code for Sustainable Homes.
Further research appears to imply the rules were changed after the election in 2011, which may by removing domestic appliances from Level 6 (zero carbon) have removed the requirement for blocking the use of gas:
"To qualify for the standard, the government says, housebuilders no longer have to supply zero-carbon power for domestic appliances. This will have a significant effect on the zero-carbon homes built after 2016, when the new zero-carbon target takes effect. Early zero-carbon prototypes, notably those on BRE’s Innovation Park near Watford, already look like historical oddities. Each home had to generate power for everything including appliances from on-site renewables, which meant these homes had to be engineered to save every last milliwatt of energy out of the building fabric and maximise energy gathering from solar panels. Some of the homes looked as if they had fallen off a spaceship rather than come from a catalogue of standard designs."
In the end I may have to revert to the old days and contact the sources directly, but it seems had Labour got in again this would certainly have been the case, but the small alteration (ie they still aim for zero carbon, but by using off-site offsets as part of the equation eg by building wind turbines to compensate for the gap between them and 0%) but does appear the original rules would pretty well require a total reliance (a contradiction in terms) on renewables. I'll keep checking but it's getting late.