The use of renewable technologies on commercial buildings is something which is at an early stage in Europe. This is due to regulations doing catch up and emissions regulations starting to arrive. In the UK from 2018, it will be unlawful to rent any property, domestic or commercial unless the meet an EPC (Energy Performance Certificate) of E or higher.
Another reason for the lack of deployment historically on commercial buildings was that the main technologies like solar hot water & heat pumps need Government subsidies to make them financially viable. These technologies date from the 1800's and have outdated performance efficiencies.
Retrofitting existing commercial buildings with HONE is also straight forward. Roof space is generally the challenge but integration with existing heating, cooling or electric systems is straight forward.
Imagine, it is raining heavily and you have your under floor heating running and then the sun comes out and starts shining in the windows of your nice new house, the temperature will climb rapidly and you won't be able to stop your heating system for 4 hours and all that energy will make your home very uncomfortable for several hours. By using radiators, you can turn your heat on instantly and turn it off instantly; thus using the correct amount of energy and keeping your home at the right temperature. This is worth considering especially if your building has lots of glazing.
Using radiators in a modern A3 or better means only a few slim radiators are needed, typically only 6 in a 2,000 sq ft home and not under any window so your walls are clear. The design considerations have all changed.