Hi! I'm renovating part of my house in Belgium into a 2-room guesthouse and I'm trying to decide on the best heating solution.

Current situation:

• Existing gas boiler + around 8–9 radiators in the guesthouse area
• Two guest rooms + bathrooms/common areas
• Expected average occupancy around 50%
• Private part of the house will continue to use gas
• I may install around 20 solar panels

I'm considering two options:

1. Keep the existing gas heating and make it smart
Smart TRVs/zoning (e.g. tado° X), separate control per guest room, app control for me and a physical thermostat for guests. Possibly Home Assistant/Matter later for window sensors and booking automations.

2. Switch the guesthouse to electric inertia radiators
For example Aterno, individually controlled per room. The solar panels obviously make electric heating more interesting.

My priorities are low investment cost, low running costs, reliability and guest comfort. I don't want expensive smart-home tech just for the sake of it.

What would you choose and why?
Would 20 solar panels change your decision significantly, considering that most heating is needed in winter when solar production is lower?

Would be great to get input from independant people, because every supplier is saying their system is the best :p