ᐅ Which heating system is suitable for KfW70 standard houses: underfloor heating or alternatives to gas condensing boilers?

Hello everyone,
we are currently planning the construction of a new single-family house. Like many others, we are now facing the question of which heating system is the right choice. One thing is certain: we want underfloor heating in the house.

The following options are under consideration:
- Gas condensing boiler (natural gas connection is available on the property)
- Air-to-water heat pump
- Micro combined heat and power (micro-CHP) system

The living area of our house is approximately 180 m² (1940 sq ft). The heatable area according to a heating contractor’s quote is about 250 m² (2690 sq ft), including the ground floor, upper floor, and two basement rooms.

At the moment, we are leaning towards the micro-CHP system, but we would like to know if it is cost-effective or if the heating costs in a KfW 70 energy standard house are so low that we actually need very little heating energy.

Thank you in advance for your suggestions.

Hello,

Neubau_EFH schrieb:
Hello everyone,
we are currently planning the construction of a new single-family house. Now, like many others, we are facing the question of which heating system is the right one.

This is one of the most frequently asked questions here. Ultimately, the answer is always the same:
A reliable and dependable answer is only possible once the actual demand (capacity, energy) for heating, hot water, and if applicable, ventilation has been calculated beforehand (basic assessment). Based on this, only then can the suitable and truly cost-effective concept be determined. Those who skip this step risk making a wrong investment. What makes sense for A may barely work for B and turns into a money pit for C.
There simply is no universal “one-size-fits-all” solution!

Neubau_EFH schrieb:
...Our current preference is for a micro combined heat and power system...

In most cases, this is uneconomical for single-family homes!

Neubau_EFH schrieb:
... or whether the heating costs for a KfW 70 house...

The heating costs for a KfW 70 house can be completely different from yours! How high will yours be? Also, not only heating costs are relevant but also the share for hot water and, if applicable, ventilation 😉

Best regards

Hello €uro,
thank you very much for the information!
I will contact our developer regarding the site investigation. They should be the right contact person for these questions, correct?

Best regards

Hello,

Neubau_EFH schrieb:
Then I will contact our general contractor regarding the initial site survey. They should be the right contact for these questions, right?

In theory, the general contractor should be the right contact. However, the subjunctive is intentional because in practice, the situation is quite different. The focus here is mainly on sales rather than consulting, planning, and sizing. Often, installations are put together rather haphazardly, which is rather inefficient. Very often, the subcontractors of general contractors in this trade lack expertise. Experienced system installers can compete in the market without a general contractor. 😉
Since this is not a new insight, more and more clients exclude this trade from the contract from the start and outsource it. The initial site survey, planning, and sizing are then carried out by an independent building services engineer.

Best regards

Thank you for the information