ᐅ Operating Ancillary Costs in New Single-Family Home Construction – Survey

Hello,

we are planning to build a single-family house (around 150m2 (1,615 sq ft)). We would like to build as energy-efficiently as possible (ideally KfW 40+), even though we are not yet sure if that fits our budget.

The more energy-efficient, the lower the additional costs – that much is clear. We are interested in what kind of additional costs you have in your KfW X houses. Electricity, (waste)water, waste disposal, etc. I understand there are regional differences. If we build, it will be in Brandenburg.

Thank you very much for your answers!

This is roughly as meaningful as asking: “My car weighs 1.5 tons—what is your consumption like?”

I’ve seen electricity consumption ranging from 1,200 to 8,000 kWh.

Water usage can also vary greatly depending on shower habits, garden size, etc. Prices range from about 2.x euros per cubic meter (m3) of water/sewage up to 6.x euros per m3.

Waste disposal fees also differ by district; some places put almost everything into the general residual waste bin, while others require thorough sorting.

Property tax depends not only on the size of the property but also on the municipality’s tax rate.

However, you can inquire about all these prices in advance from the utility providers! How much you will actually use can be estimated easily by looking at the utility cost statements from your current residence and adjusting according to local price levels. For electricity, add about 500 kWh for heating and controlled ventilation if you have a gas boiler. For rough estimates, assume around 3,000 kWh electricity consumption with a heat pump, or about 40 euros for gas at that size.

The fact is: The savings in operating costs for KfW X relate exclusively to heating and, under normal circumstances, are unlikely to pay off over the house’s lifetime without additional subsidies. If you keep all the lights on 24/7 everywhere, even the best KfW X house won’t help. The same applies to water consumption, disposal fees, and property taxes.

Electricity is roughly balanced over the year due to investment in (unreasonably expensive) solar panels.
Heating is supplied with raw materials from our own forest – which takes time, so I don’t include that cost.
Fees and charges – it is what it is.
Children’s apartments as separate living units with a bathroom and kitchenette – in case space becomes tight later, they can be rented out as holiday apartments.
Therefore, ongoing utility costs don’t matter much, as they can be offset.

That was the concept – we didn’t really build with cost optimization in mind, but we also don’t want to have to move out if our finances change. Now some capital is tied up, but we sleep well and feel comfortable. That’s what it’s all about, isn’t it?

We have a KfW40+ house with 205m2 (2,205 sq ft) and, after two years, our average annual consumption for electricity, heating, and hot water is:

2900 kWh/year (primarily in winter)

and we feed back

2100 kWh/year (primarily in summer)

(so effectively a net consumption of only 800 kWh/year)

Our self-consumption rate with our small 5 kW photovoltaic system and battery is about 50%. With a larger system, I could hardly achieve much more since it would only help us on very few days of the year.

We have a green eco tariff with shared decision-making on how the local utility invests part of the profit. Please calculate yourself what your costs would be. The annual additional costs for the house are definitely not my biggest expense; much more money is spent in the hardware store, at least in the first two years...

Water: It really depends. In the first six months, there were just two of us using only 7 m3 (247 ft3), but the garden wasn’t set up yet, and we were still on vacation and usually showered at the gym. Then the garden was established, and we needed to water it, which used up 150 m3 (5,295 ft3); our neighbors used 300 m3 (10,590 ft3). Now we have a well, automatic garden irrigation connected to the pump, and everything is different again. Since water and wastewater fees, like waste charges, vary widely, you will need to research this yourself. If you have to water your garden with municipal water, you should have a separate meter installed for this so you don’t pay wastewater charges on it. Otherwise, I strongly recommend having a well.

Regarding waste, it depends on the size of the containers you choose. For residual waste, we have the smallest bin emptied every two weeks. For organic waste, despite having a compost, we have a medium-size bin emptied every two weeks. Paper is collected every four weeks, recyclable materials every four weeks in a very large bin (in our area, only the large bin is available).

Then there are building insurance, household contents insurance, property tax...