ᐅ District heating versus air-to-water heat pump for KfW 40 Plus standard

Hello everyone,

we are currently planning our single-family house (about 160 m² (1720 sq ft)). It will be built using a timber frame construction method with a basement. The prefab house supplier offers a standard KfW 55 house. The rooms will be heated with underfloor heating.

In the building area, connection to the local district heating network is mandatory unless you build a KfW 40 plus house.

I have compared the possible costs.

District heating:
District heating connection including transfer station €8,948.80 (offer)
Additional costs for an extra heating circuit for underfloor heating €952.00 (offer)
Hot water storage tank €1,000.00 (estimate)
Connection costs for “heating” €3,000.00 (estimate)

Base price per year: approx. €350
Price per kWh: 10 cents gross

Total €13,900.80

Upgrading to KfW 40 plus:
Additional wall insulation €5,590.00 (offer)
Photovoltaic system €5,590.00 (offer)
Battery storage €7,990.00 (offer)
Air-to-water heat pump €3,000.00 → offset against current planning (estimate)
Additional basement insulation: €2,000.00 (estimate)

Total €24,170.00
Minus KfW 40 plus subsidy €10,000

Adjusted total €14,170

I have to admit the consultation with the energy advisor is still pending. They will probably be able to say exactly which measures are necessary to reach the KfW 40 plus standard.

Would you continue pursuing this option, or is KfW 40 plus with a basement unattainable? Starting with the existing district heating and then switching later in about 10 years probably doesn’t make sense either?

Thank you very much for your feedback!

Best regards,
Björn

The repayment grant for KfW40plus is €15,000. For KfW40, the repayment grant is €10,000. Unless it is the difference between the repayment grant of KfW55 and KfW40plus.

I will be building a timber frame house with a basement myself, which meets the KfW40 standard. However, not the 40plus, because currently the battery storage systems are not cost-effective for me. If I had been required to connect to a district heating system, I probably would have chosen the KfW40plus option. That way, you are somewhat more independent, even if you cannot predict how electricity prices will develop. With district heating, however, you are tied to one provider. At the same time, you get a better-insulated house.

Is a ventilation system with heat recovery included in the KfW55 house offer? This is mandatory for KfW40 and KfW40plus.

This is just my layperson’s opinion; the energy consultant will surely be able to explain in more detail how the ongoing heating costs differ.

World-e schrieb:
The repayment subsidy for KfW40plus is €15,000. For KfW40, the repayment subsidy is €10,000. Except when it is the difference between the repayment subsidy of KfW55 and KfW40plus.

It is the difference between KfW 55 and KfW 40 plus.

The offer for the KfW 55 house already includes a ventilation system with heat recovery. The basement insulation is currently 14 cm (5.5 inches).

Of course, it must also be considered that the additional costs have to be covered from equity if the loan agreement has already been finalized.

Are there any KfW 40 plus homeowners here in the forum?

District heating sounds quite unattractive. The initial investment costs are considerable, you are tied in; the annual base fee is outrageously high and the price per kWh is also expensive. An air-to-water heat pump can generate one kWh of heat at comparable costs (with a COP of 3, given the current electricity price, it’s under 10 cents). You could also simply use this in a KfW55 house, for example, and the overall cost would be much lower than with district heating.

I have now received more precise figures:

District heating
Base price (for the first 15 kW) €401.57
Basic energy price 10.12 cents/kWh

The problem is that, under the standard district heating option, I am not allowed to install an additional heat source in the house. Only with a KfW 40 Plus standard house would I be exempt from this. On the other hand, the technology in my house with district heating is quite simple. From my perspective, there is less that could break down, and maintenance is included in the price.

With a KfW 40 Plus house, I would have to maintain and look after the photovoltaic system, the air-to-water heat pump, and the battery storage. Battery storage systems also still have room for improvement.

I’m torn between the options, but the builder is supposed to run the calculations for me.

Hello,

skybiker2000 schrieb:
I have now received more precise figures:

District heating
Basic fee (for the first 15 kW) €401.57
Basic energy price 10.12 cents/kWh

The problem is that under standard conditions, with "district heating" you are not allowed to install any additional heat source in the house.

That price is definitely more than unreasonable. For comparison: we currently spend about €400 per year on gas for a gas heating system heating 135 sqm (1450 sq ft) plus a 60 sqm (645 sq ft) heated basement. That’s about the same amount they want to charge you just as a basic fee...

And you are completely at their mercy, since you cannot even change the supplier like you can with electricity when using a heat pump.

And the second restriction obviously serves to secure the provider’s future business.

For me, that would be an absolute no-go.

Best regards,

Andreas