The task of choosing a heating system for a self-build or extensive renovation is no longer about simply plugging in a boiler and some radiators. We now need to take a holistic view and put efficiency at the forefront of our mind - and that starts with the fabric of the building. A well insulated and draughtproof home will require a smaller heat source, which will also operate for a shorter time. As such, decisions regarding what heating and hot water system to plumb for should only be made once we know the details of the insulation levels in the home and the way the home is going to be used by its occupants. Added to this is the fact that the old mainstay, the gas boiler, is no longer our only choice; renewables tech such as air source heat pumps and biomass have come onto the radar and the arguments in their favour can be very compelling.
As the energy efficiency of a property improves, things can get to the point (especially with Passivhaus and other low-energy buildings) where the energy required to heat the home’s hot water is about the same as, if not more than, the energy required to heat its rooms. This is an important factor to consider when selecting a heating system, as the high temperature demand (for hot water) can now potentially be bigger than the low temperature demand (for heating) and so the specifications of the technologies used need to take that into account.
You may be thinking that natural gas is on the way out, with certain information indicating that boilers may be banned from being installed in new homes from 2025. Whether this happens or not, we will certainly see the gas grid get a lot greener in the next few years and I would still be inclined to allow for easy change in the future. If you do fit a gas boiler then there is no reason why the emitters cannot be fitted in such a way that they are also compatible with low temperature renewable heat technologies, allowing an easy retrofit in the future.