Gas without solar possible for new construction?

Hello,

A KfW40 house has a calculated heating demand of 25 kWh/sqm, from which the 4000 kWh result.

...the word "calculated" heating demand is the decisive one here. This calculation is only marginally more realistic than consumption values for cars. Minor things like children who go in and out every 5 minutes in winter, leaving the front door wide open for 2 minutes each time, or the bathroom window that is opened after showering and unfortunately remains open for the next 3 hours because it was forgotten, or the fresh air fanatic who insists on cross-ventilation despite controlled living space ventilation, are not accounted for. In other words, reality is somewhat missing...

For real life, you can quite reasonably add 50% or more as a surcharge.

Best regards,

Andreas

The additional costs for controlled residential ventilation with gas were taken into account.

Option 1 Air heat pump + controlled residential ventilation: Tecalor THZ 504 +€36,800 (compared to gas)

Option 2 Gas: Wolf CSZ (incl.) Controlled residential ventilation: Tecalor TVZ 180: +€17,600

Calculation (current prices from Check24 today): - Heat quantity = 12,000 kWh per year - Gas: ~€1,800 per year - Electricity (annual performance factor: 4): 12,000 kWh / 4 = 3,000 kWh => €1,214 - Difference: €586 per year

1. Prices unrealistic. May depend on the general contractor. For another one where we were in the planning phase, a 4 kWp photovoltaic system and 4 kW storage would also have cost an additional €20,000.

2. You have to consider with photovoltaic installation that with a heat pump you can run at least part of the heating via the photovoltaic system. That is not possible with gas. Thus you have another point in favor of the heat pump.

Hi,

...the word "calculated" heating demand is the key here. This calculation is only slightly more realistic than consumption values for cars. Small things like children who go in and out every 5 minutes in winter, leaving the front door wide open for 2 minutes each time, or the bathroom window that is opened after showering and then unfortunately left open for the next 3 hours because it was forgotten, or the fresh air fanatic who insists on cross-ventilation despite controlled residential ventilation, are not included. In other words, reality is somewhat missing here...

For real life, you can certainly add 50% or more as a surcharge.

Best regards,

Andreas

This exactly does not apply in reality. Much more often, the actual heating load is lower than calculated. It starts with flat-rate surcharges for thermal bridges and ends with internal gains. Large window areas also promote warming due to low-lying sun, and roller shutters have an effect as well. The better the insulation of the house, the greater these aspects become. Cooking, television, people, tealights... all of these are internal gains that the heating does not have to provide.
By the way, children can be taught to close doors. I know this because I did it.

Attention, off topic…

You can do everything with it, just not fly ... not yet. ;-) I assume that this caravanboat will replace the usual trailers and caravans. From my point of view, there is no longer any reason to buy a trailer or caravan if you can have a caravanboat instead.

Don’t overestimate the business idea: this thing doesn’t compete with a trailer, since it is way too big, heavy, and expensive. Those who can afford it probably already have a proper boat at their dock, own a lakeside property, or otherwise need to get rid of their money. Investors will more likely rent this thing out rather than move it back and forth themselves.
08/27 … the date conflicts with the Caravan Salon in Düsseldorf :oops:

...the word "calculated" heat demand is the crucial point here. This calculation is only slightly more realistic than consumption values for cars.

I am relatively close to the standard consumption and sometimes even below it. But of course I also know people who constantly start their car for short and very short distances, which naturally causes double-digit consumption and wears out the car like crazy. The same applies to heating. In our heating cost statement, we always pay significantly more for the square meter share than for consumption, even though we have a second exterior wall and most neighbors have only one. In a single-family house, I certainly expect us to be in the range of the calculated demand. Beyond the possibilities mentioned by , the bedroom also comes to mind. We don't need 22 degrees there, so the heating demand is significantly lower.

A floating caravan or do you mean a houseboat?

Addendum: It's settled for us. My husband told me earlier that the price of around €99,000/100,000 from about 3-4 years ago has now risen to €200,180. :-( The demand seems to be high, otherwise such price increases, as I assume, would not be possible.