Interesting, but what will the town planners have to say about such a radical idea.

Poor journalism from the BBC - they should get the Kingspan claims checked:

"The home generates all its own energy" - impossible - it may be net zero but does rely on the grid as there is no electrical store.

"It counts as zero-emission because the carbon dioxide it gives off during the burning process is offset by the amount absorbed when the fuel crop was grown."
Not correct as the farm, processing plant, delivery, etc will not be carbon neutral. Biomass is close (about 1/10 of gas in CO2 intensity), but not that good.

The design is a gimick and a zero Carbon home could be built allong more traditional lines (I am not saying that traditional design is good -far from it).

Key design features of a 'Zero carbon home':
Big south facing roof (solar)
Multiple floors (eg 3 levels and one roof means less heat loss per floor)
Terraced (remove heat loss from two entire walls)
Solar Hot water
Biomas where practical

But why zero carbon - the extra 40% cost is a waste!
I am performing energy calcs every day and find it is easy to get 90% of the benefit for 10% extra cost
After that is is diminshing returns, chasing that last bit of CO2 with technology that is still over prices (Solar PV)
The money would be far better spent on large scale renewables... (economy of scale).

The carbon emissions all relate to the Code for Sustainable Homes and SAP calcualtions. The house will be NET carbon neutral i.e. over a whole year the emissions are zero as electricity is imported/exported depending on what is happening in the house.

Don't forget, the house was designed for an exhibition by a SIPS manufacturer to demonstrate their product. It gets a Code level 6 and is the first in the UK to achieve it. It is all pure marketing. The 40% extra cost would reduce in a large development but will still be extra, especially as it's covered in PVs, but it's a demonstration product so of course they are going to spend loads of money on it.

All the claims have been checked as the Code assessment process is quality assured by BRE on behalf of the government.

According to the leaflet I picked up yesterday at the Offsite exhibition, it can be designed as a 2/3 bed, 4 bed, semi, terrace, apartments... and on large developments, energy could be generated centrally using biomass CHP.

Peter,

I am basing my estimates on the SAP methodology (not on reality)

As a notional and quick analysis, Take a 100m2 new build and do the following:

Don't bother with adding more insulation(!!!)
Fit a wood boiler
>Looking at the range of prices for wood boiler (simple back boilers to state of the art wood pellet) this would be an average of £4,000
>The SAP rating should be at CSH level 4

To go to Level 5 (zero rating in SAP)
Add around 2Kp Peak of Solar PV per 100 m2
I believe it should be possible to get this for a net cost of £6,000 (?)

So a very rough estimate of £10,000 on a 100m2 house (starting at least £1,000/m2 standard build cost).

It's not the ideal route in terms of sustainability but it does mean that the house is a NET zero home in terms of its basic needs (lighting, ventilation and heating).
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The attachment is an example of a reasonably good home with a wood stove linked to a Solar hot water sytem (the solar does not save any significant extra CO2 over the basic boiler) and Solar PV
(Note: It is also reasonably air tight and has a default spec HRV)
It achieves level 5.
The SAP Target is around 2,000Kg CO2/pa
Without PV the home is around 800KG CO2/pa so a 60% improvement, easily level 4.
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What I would like to see is:
level 4 achieve primarily through insulation/airtightness and ventilation
Solar hot water mandatory on any fossil fuel home (with an available roof)
(Solar PV will, one day, be financialy viable to take us up to level 5, but not yet)

I do not have costings on this approach but will be generating them later this as we start designing our own SIPs homes