Heat pump - Is it only worthwhile with KfW55 insulation?

We want to build with DEURA. By default, they build with 36.5cm Poroton bricks, without additional insulation on the exterior walls. The extra costs to meet the KfW55 requirements are estimated at about €10,000. To save costs and because KfW does not benefit us much for financing, we want to leave out the additional expenses. Now to my question: do you think we are right to build with a heat pump, or is it only worthwhile if the house is really insulated according to KfW55? The topic of heat pumps is rather controversial, and I am considering switching to gas.

I can only say this from my humble opinion, I don’t have real expertise, but I think if you only want to install a heat pump without additional energy sources like [Photovoltaik], then you are better off with gas. The heat pump runs only on electricity, and electricity prices will rise more over the next 10-20 years than gas prices. Of course, I could be wrong.

The gas price will rise more strongly than the electricity price over the next 10-20 years. But of course, I could be wrong.

Both systems provide heat and achieve the goal. But if gas, then design the system so that a switch to a heat pump is possible later. Anyone building with gas today must be aware that politically, from 2030 at the latest, it will no longer be desired for initial installations, i.e. replacing the boiler will only be possible due to grandfathering rules, which in the past led to high effort when changing ownership ... but who really knows.

I think what will happen in 2030 does not need to be considered today. For FB heating, use the smallest possible pipe spacing, then you can easily operate with a low flow temperature, which saves energy both with gas and heat pumps. The additional cost for a few meters of pipe is minimal...

I would bet on gas today because the additional cost for a heat pump will never be recovered. And even if you put photovoltaic on the roof, it doesn’t save you anything because in winter it hardly provides any energy and in summer I don’t need it for heating.

just my 2 Cent

This way, one can push the arguments back and forth. Ultimately, personal preference and the price of the systems decide. For me, gas is outdated. The price is historically low and tempts one to assume that this will always be the case. Price doubling within a year is quite possible. Additionally, there are political ideas like CO2 taxation. The electricity price is historically high and primarily determined by politics, not by international crises or speculators. It is difficult to think about 2030; in fact, it is not that far away anymore, as the first replacement of the boiler is likely to be due after this date. In new buildings, the share of hot water supply in the total energy demand is around 30-40%, so a photovoltaic system can definitely contribute something in summer regarding the annual heating costs. But this should not be overestimated; after all, the photovoltaic system is not free to acquire.

In new buildings, the share of hot water supply in total energy demand is about 30-40%, so photovoltaic systems can certainly contribute something in summer with regard to annual heating costs. But this should not be overestimated, after all, photovoltaic systems are not free to obtain.

This is an important point that must not be forgotten, especially with growing children! Because of the large differences in winter, the air heat pump works particularly inefficiently and also noisily here. Therefore, a ground source heat pump is better. It always depends on the individual case. A passive house in the Lower Rhine region with two residents will perform great with a good air heat pump, including the BAFA subsidy..