Ongoing costs of a passive house?

Good morning everyone!

My wife and I started yesterday to set up our budget in preparation for building a passive house or at least a KfW 40 house (130 - 150 sqm, 5 rooms, 2 children and both of us). I was not clear about what monthly ongoing costs we should expect. So far, we have planned 325 euros per month - i.e. including electricity, water, garbage, and whatever else occurs monthly for the house, which is 2.17 euros per square meter for 150 sqm. Is that sufficient, especially if the house will probably be rather 130 - 140 sqm, and are *all* ongoing costs really covered (of course except for the loan repayments)?

Thanks in advance!

Best regards,
Christian

P.S.: Would you actually build with or without a basement, and to what extent would that affect the ongoing costs? We tend to go for a basement, but we don't know if we can finance it.
Our favorite is currently Viebrockhaus, because Viebrockhaus convinces us. But we are also currently looking around Göttingen.

Electricity, water, and garbage can be inquired about at your municipality. Home insurance costs another (in our case about €300 for household contents and liability including fire, storm, etc.). Property transfer tax depends on the assessment rate of your municipality - it can be anywhere from €70 to over €500 per year - depending on the size of your property, house, and the set assessment rate. Heating is not a big issue in a passive house; if a controlled residential ventilation system with heat recovery is used, you will of course have electricity costs for this device - AND electricity consumption according to the manufacturer often has nothing to do with actual electricity consumption.

In my opinion, the question about the monthly costs is hardly answerable. No one knows your electricity consumption, since we don't know whether you have old or new appliances, how often you run the dryer (we currently do almost daily), how often you use the oven, or how many freezers are in operation.

We have a KFW 55 house and manage with the following payments:

about 45 € gas per month for heating/cooking and hot water (reduced by solar for hot water) about 60-70 € electricity 40 € to the municipality for water and property tax 20 € waste 50 € insurance related to the house and risk insurances 50 € telephone and internet 18 € broadcasting fee 30 € proportional construction costs in the municipality as a recurring contribution 35 € maintenance of heating, ventilation, and soft water system

Of course, this is all very roughly estimated. What is added for us are about 150 € extra fuel costs and 70 € for a public transport ticket, since we now have a significantly longer commute and also cannot just walk to the supermarket like we could in the rented apartment. Saving for possible repairs to the house in a few years should also be considered.

Generally, I have to say, we gave up relatively quickly on the passive house idea because the costs were disproportionately high compared to the expected cost savings in consumption. KFW 70 was aimed for; it then became KFW 50.

Regarding the basement, everyone has to decide for themselves whether they can do without it. We don’t have one because the money was simply too expensive for us to invest an additional 50,000 €. The result would have been that we would have only had 120 sqm in the living area instead of 150 sqm. We currently do not have one, but we miss it, especially since we also don’t have a garage yet... once that is eventually built, we might finally be able to declutter inside. At the moment, two strollers, a tricycle, and other stuff are standing in the hallway under the stairs... you really don’t want that inside the house.

Hello Christian,

My wife and I started yesterday to set up our budget in preparation for building a passive house or at least a KfW 40 house (130 - 150 sqm, 5 rooms, 2 children and the two of us).

A PH only makes sense if at least one person is in the house during the day – when calculating to PH standard, the body heat of the occupants is also taken into account. You can wonderfully observe what it means if the house is largely empty at the example of a model house in Lehrte. The green colleague competitor wanted to show with this model house what he is capable of delivering. With the result that the colleagues working there sit in the office with a fan heater during the transitional period and winter days. From this experience, the so-called solar house developed, which embraces a 7000-liter buffer storage tank.

The other aspect, of course, is that a PH is a building in which a comfortable temperature can be achieved both in winter and summer without a separate heating or air conditioning system. It is supposed to offer increased living comfort with a heating energy demand of less than 15 kWh/(m²a) and a primary energy demand including hot water and household electricity of under 120 kWh/(m²a). Of course, this means you have to invest a lot of money.

Economically reasonable from my point of view is currently KfW 70; for the red colleague competitor also KfW 55, because his wall construction allows for it anyway. Only the exhaust air heat pump should be replaced by another system.

What are the reasons you are considering KfW 40 or PH?

I was not clear about what monthly ongoing costs we should roughly expect. So far we have planned 325 euros monthly – that means including electricity, water, waste, and whatever else comes up every month with the house, so 2.17 euros per square meter with 150 sqm.

If you stick with KfW 55 – the standard of the red colleague competitor, you will not manage with your above-mentioned costs. He uses an exhaust air heat pump as standard and this is not sufficient to properly heat a house. The internet is full of builders who have had to soberly acknowledge that a house below PH standard with this system, which basically corresponds to a controlled residential ventilation with heat recovery, cannot be heated comfortably.

P.S: Would you actually build with or without a basement, and how would that influence the running costs? We tend to lean toward a basement but do not know if we can finance it.

I face this question every day and therefore answer you as I also explain to our interested parties.

From my point of view, a basement only makes sense if it either results from a hillside location (the required earthworks for such a plot are not insignificant, so a basement always pays off) or if the basement is converted into living space. Because as a rule, with a pure utility basement, the following happens: the desired basement is fully used as storage space. Heating supply temperature. In the rear, larger basement, there might be a party once or twice; soon, however, the person responsible for housework notices that the terrace and garden are much easier to clear of party debris. Afterwards, the basement still houses the utility connections, possibly a washing machine and dryer, and a storage room – the rest is used as storage. For moving boxes, furniture the builders do not want to part with, decorations, etc.

For a house of the size 140/150 sqm, a pure utility basement costs about 40 thousand euros, for living space conversion another 20 thousand euros for the required insulation, underfloor heating, living space windows, and interior plaster. Floor and wall coverings are not yet included. For this money, you can better build above ground; unless you want to create a utility garden and need storage space for the harvest of potatoes & co., as the generation of our parents has done before.

The running costs only increase if it is to become a living basement; with a utility basement you have "only" a higher upfront investment, which you have to consider in financing.

Rhenish greetings

We moved into our KfW 40 house with approximately 160 m² of living space at the end of January. Since then, I have been monitoring the electricity consumption for our air-to-water heat pump, and from the end of January until now, the average is about 8 kW per day for heating and hot water.

However, one must also consider that it was unusually warm during this period, and consumption will certainly be significantly higher in a harsh winter.

As for the question about other ongoing costs, you have to answer that yourself. It depends on the number of people in the household, lifestyle, place of residence, and several other individual factors that an outsider cannot reliably assess.

Regarding the cellar question. We don’t have one and don’t miss it either. I share Epis' opinion. A functional cellar often becomes a junk room, and at least in my case, I was usually too lazy to carry things constantly down and up again in the previous rented apartment. That means items used "daily" eventually find another place somewhere in the house, garage, or garden, and the cellar often only ends up as clutter. Therefore, burying 40-50 thousand euros in the ground was not worth it to me.

The idea that inspired me to build: the luxury of no longer having to go underground