ᐅ New Single-Family Home Construction – Gas or Air Source Heat Pump + Photovoltaic System + Energy Storage?

You definitely need an energy consultant. They can then tell you what you need.
In our case, the general contractor handled everything. I hardly had to do anything except be at home for the inspection appointments and sign a few forms beforehand to send to the energy consultant.

I can’t confirm that the costs only break even. Our house already met the Kfw55 requirements; the only choice was between a gas heating system (which would not qualify for Kfw55) and a heat pump (which would). This resulted in additional costs of about 4000 € (approximately 4,300 USD), but with a subsidy of 18,000 € (around 19,300 USD), the decision was easy.

motorradsilke schrieb:

to be home only for the final inspection appointments

Final inspection appointments? Plural? What exactly is being inspected and when?

motorradsilke schrieb:

the only option was between a gas heating system (then no KfW55) and a heat pump (then KfW55)

That choice is not really mine. There is no gas connection at the plot, but for about 3,000 euros I could have it installed. However, I’ve now requested a quote from a local supplier for a photovoltaic system. 10 kW + storage for 27,000 euros, and suddenly the subsidy of 26,250 euros disappears.

nullhorn schrieb:

Final inspection dates? Plural? What exactly is inspected and when?

I don’t really have a choice here. There’s no gas connection at the property, which is fine—I can have it installed for around 3,000€ (about $3,200).
But I just got an offer for a photovoltaic system from a local provider: 10 kW plus storage for 27,000€ (about $29,000), and just like that, the subsidy of 26,250€ (about $28,200) is gone.

The shell construction stage (though you don’t necessarily need to be present for that) and the blower door test.
Then, the energy consultant told me that the builder still needs to provide various documents, basically proof that the materials used match those specified in the application. For example, the thickness of the insulation material was also verified by measurement.

I wouldn’t include photovoltaics in this calculation, since it’s supposed to pay for itself (we don’t have one; I want to look into whether it’s really worth it next year—first, we need to see how much electricity we actually consume, since we mainly use wood for heating). But even if you install one, you should offset the saved electricity costs against the investment.

@nullhorn Skip the battery storage. It will eat into the profitability of the photovoltaic system. More information available via private message.

@nullhorn When are you planning to build (approximately which quarter), with whom (general contractor or individual contracts), and what type of construction (solid construction or timber frame)?

It is currently not unlikely that the new government will introduce some kind of immediate program that directly affects you. There are things that must be determined during the planning phase, but there are also aspects (e.g., sizing of photovoltaic systems, possibly storage) that can be defined during construction depending on the current funding programs.

A good energy consultant is much more than just someone who crunches numbers for the building permit / planning permission and energy efficiency financing. They can particularly help optimize the construction method, building services, and funding options. I would recommend trying to find a committed consultant and involve them from the very beginning.

@motorsilke ... For example, my energy consultant told me that for KfW 55 EE with 42cm (16.5 inches) masonry and triple glazing, 1. no additional insulation and 2. no blower door test are required.

@Hangman ... Construction will start in the first quarter of ’22 (hopefully). Since it’s a well-known family business and I’m “not really” in a hurry, I’m leaving it up to the shell construction company to decide when to pour the foundation slab and start masonry work. That also settles the other questions – individual contracts, solid construction with T8 or T9 42.5cm (16.7 inches) blocks (according to the energy consultant + triple glazing + heat pump + photovoltaic system, this meets KfW 55 EE requirements).

Hangman schrieb:

@nullhorn When are you building (approximately which quarter), with whom (general contractor or individual contracts), and what type of construction (solid or timber frame)?

It’s still possible that the new government will introduce an immediate program that affects you directly. Some decisions have to be made during the planning phase, but others (e.g. sizing of photovoltaic systems, possibly energy storage) can be defined during construction depending on the current subsidy programs.

A good energy consultant is much more than just a number cruncher for building permits and KfW applications; they can especially help optimize the building method, home technology, and funding opportunities. I would try to get a committed consultant involved from the very beginning.

Here in this region? No chance. You can only choose between those who do the bare minimum, either expensive or cheap.