ᐅ Which home technology systems are advisable?

Hello everyone

I’ve been following this forum for quite some time. It has given me some useful insights, but I feel there’s still a bit missing.
First, here are the key facts: We want to build a Tuscany-style house (solid construction) measuring 10m x 10.5m (140 m² (1,507 sq ft) living space) with a garage in northern Germany. It will be a KfW 70 energy standard house.
I’ve been pondering for a long time about what would be the most sensible and effective solution for our region and situation (two-person household, possibly up to four in a few years, both working).
We are considering either
- a solar thermal system for hot water,
or
- a solar power system of about 3 kW with self-consumption combined with an active ventilation system with heat recovery.
What do you think would be more suitable? Am I missing anything?

Thanks in advance for your help!

There is already a lot of information about active ventilation and exhaust systems here in the forum and generally on the internet. We will install one and know from colleagues who have one that they never want to do without it again.
We are building to KFW 55 standard, where this system, as well as solar for hot water, is mandatory.

But keep in mind: a ventilation system causes additional costs if a wood-burning stove is planned, and only recirculation air is allowed in the kitchen, no exhaust ventilation.

Hello,

Zecke schrieb:
...I've been pondering for a very long time now about what would be the most practical and effective solution, ..

Pondering alone won’t bring much insight here. A solid basic assessment is necessary first (performance and energy demand for heating and hot water). Only after these calculations are made can different solutions be compared and evaluated.

Solar thermal systems rarely come out as the preferred option. On the other hand, the combination of a ground-source heat pump with or without photovoltaic panels is quite common for KfW 70 standard.

Best regards.

€uro schrieb:
The combination of a brine heat pump with or without photovoltaic panels is quite common in KfW 70 standard buildings.

I'm a bit confused right now, solar thermal system is clear: Solar Thermal Application.

Energy demand: currently, there are two of us and both work full-time. So we use very little energy, and if anything, only after 4 p.m. I’d say it’s difficult to determine.

Zecke schrieb:
..., energy demand, ....

The values refer to the building project. Obviously, no one would want to build without first knowing what the future energy costs will be. These depend on the building structure, the climate location, user behavior, and the installed systems.