Interesting system, but 350W per square metre isn't going to deliver a lot of heat. Any idea of cost per sqm?
To install this system, you do need to add another isolated layer on top of your existing walls. The plasterboard layer supporting the paint needs to sit over electrodes spanning the heated area. So it will take some space from all rooms, though perhaps just 20-25mm unless you're replacing the existing plaster. I don't see full installation specs online anywhere as they suggest is must be professionally installed.
I love their comment on one of the main advantages they're pushing:
Radiant heating doesn't dry the air, like traditional types of heating.
Ah, traditional systems here use radiators....so radiant heat... The difference with this system is they use your wall as the radiator.
Do you know what the energy requirement of the building is? This might be an option in a very well insulated space, but impractical and very expensive to run in larger or less well insulated buildings. How much of the generated head will simply conduct out through the walls? A typical small gas boiler might be around 15kW, to achieve the same heat output from this system would mean covering over 40 square meters of wall surface. For your space though your heating requirements may be lower.
The other forms of electric heating (storage / convection) are close to 100% efficient, so these cannot offer anything in that regard. So per deliverd kWh of heat energy, electricity will always be considerably more expensive than other
sources. There's an argument that a solar PV system with local battery technology could power such a system from electricity generated on-site, but the time we use heating most also coincides with the time we get the lowest levels of solar energy.