ᐅ Determining the Ongoing Costs of a House

I am currently in the very early planning stage of building our own home and need some help gathering and estimating the ongoing costs that come with such a house after construction. Basically, I want to find out how much of our net income will ultimately remain after deducting all ongoing costs, so that, for example, we can determine how much is left to cover loan repayments.

A few key details about the planned project:
- Passive house (semi-detached)
- Approximately 150m² (1,615 sq ft) living space, spread over 2 full floors
- Approximately 430m² (4,630 sq ft) plot size
- Garage
- Initially two adults and a newborn, with a second child planned
- Local multiplier (for property tax / ground tax) currently 471

From my own research, I’ve identified the following monthly cost items (all converted to a monthly basis):
- Property tax: max. €37.50 (I contacted the tax office and was told that property tax cannot be reliably estimated at such an early planning stage, but I should expect no more than €450/year)
- Electricity costs: approx. €150 (it is not easy to find reliable figures on electricity consumption of passive houses; online sources vary between 4,000 and 7,000 kWh/year. I decided to calculate with a rather high estimate of 6,400 kWh)
- Water: about €15 (assuming a consumption of 120m³ (4,240 cu ft) per year)
- Heating: €0 (a conventional heating system is not needed in a passive house, and hot water production and backup heating are usually electric. These additional costs are included in the electricity estimate)
- Waste collection: €26
- Sewage: €32
- Contents insurance: €15 (I simply used a comparison website and took the average price for coverage of €100,000)
- Building insurance: €25 (similar to the contents insurance)
- Reserves for repairs, etc.: €150 (simply the commonly cited one euro per square meter)

The following two points are not directly related to the house itself but, in my opinion, still belong among the ongoing costs:
- Internet + phone + TV: €55
- Public broadcasting fee (GEZ): €17.50

(I have tended to estimate on the safe side and rounded these numbers up where I was not able to get precise figures.)

All in all, this adds up to ongoing costs of about €523 per month. Now my questions to you experts here:
- Which ongoing costs have I not yet accounted for?
- Where have I gone wrong in my calculation or used completely implausible figures?

Thank you very much in advance!

I really like lists like this! I can't think of anything you forgot.

For the maintenance reserve, I would also add the usual ongoing maintenance costs (in addition). Maintenance of building services, but also simple tasks like clearing leaves from the gutters. Of course, this varies in each case, and many people probably handle these tasks themselves.

Depending on the size of the property and individual preferences, it’s also important to allocate a budget for the garden, not just initially but on an ongoing basis as well.

Weird_Wookie schrieb:
Residential building insurance: 25€ (similar to contents insurance)

Inclusive or exclusive of natural hazard coverage?

What about liability insurance? In other words, does your current policy already include property owner liability?

Weird_Wookie schrieb:
Heating: 0€ (a conventional heating system is omitted in a passive house, and hot water production and supplemental heating are usually provided electrically. These additional costs are already included in the electricity expenses)

No equipment that requires maintenance? No mechanical ventilation with heat recovery? No filters (mats)?

First of all, thanks for the quick replies!

Regarding liability insurance, I’ll have to convince my wife to provide the documents from our current policy. But thanks for the reminder to check on that.

I’m still not entirely sure if coverage for natural hazard damage would be useful for the plot of land we are considering. However, I definitely want to consult a professional about that.

In your opinion, should I budget €1.50 per m² (16 cents per sq ft) for maintenance and repair costs?

Somehow there has already been a general discussion thread this year... you can try searching for it, for example under additional costs.

Additional costs for a completed house