Construction costs are currently skyrocketing

I definitely won't pay 1.2 million for a 140 sqm semi-detached house with green space and garage. Currently, we pay around 1500 warm for a 100 sqm apartment with garden use

Apart from the fact that this doesn't add up (you pay 1.2 million in interest over what period?), you must not compare the two properties when considering whether it's worth building instead of renting. You have to compare with the rent of a comparable property. Net cold rent vs. interest + non-transferable ancillary costs.

Then buy a sensor and you will be amazed at what the controlled residential ventilation system does ...

Throwing the window wide open is probably only due to habit depending on the individual situation and perceiving the incoming "colder air" as fresher air....

How do you mean that with the sensor?

This is not generally due to a controlled residential ventilation system, but rather to a poorly planned controlled residential ventilation system. Small difference with massive consequences.

What should one watch out for? Or what can be planned incorrectly?

I wouldn't be so optimistic, but the trend is clearly noticeable. Let's see if we reach the May values on the 10-year swap as early as next week or not.

I also believe that it won't happen that quickly. But at least the risk of further rising interest rates is off the table in the short term (at least until the next inflation figures).

I also believe that this will not happen quickly. But at least the risk of further rising interest rates is off the table in the short term (at least until the next inflation figures)

Interhyp published a press release today - slight relief after a sharp increase. Forecast of the institutes - short-term sideways or rising, but a slow, further increase over the year, towards 4%.

What must be considered? Or what can be planned incorrectly?

Incorrect air exchange rates planned in the bedroom (e.g. simply only 1x supply air and that was it). Overall planned for only two persons during the design, but there are actually four persons in the house. Poor positioning of the ventilation openings. Etc.