Fitness Area Planning

I think calling it irresponsible is a bit exaggerated. It could be electricity from one's own photovoltaics. And for about 1 hour a day, the electricity consumption won't be that high. It's not supposed to run 24 hours straight.

Sure, photovoltaics can help in summer and in winter heating will be done like crazy. This is about a hobby and not something essential. When I think about the world for our children and grandchildren, I don't think irresponsible is an understatement.

For me, a garden shed would be nothing. You can heat up the room temperature quite quickly, but the barbell still stays as cold as an icicle. Often, some equipment is added to such training rooms. TV on the wall, sound system, treadmill, ... I would not subject these devices to extreme temperature fluctuations.

I have never dealt with the topic before. How much does the temperature fluctuate when building massively and/or insulating something? But presumably, the easiest way is to add an extension to the house and include the room in the thermal envelope.

The solution is energetically irresponsible and completely unnecessary.

Come on, that's really extremely exaggerated now. But okay!

On topic: Build 40 m2 larger on the property, install air conditioning, and have large floor-to-ceiling windows. Then you can also use the garden as an extended gym, which is really cool!

We have ours with 25 m² in the basement. However, living space quality with 2 large windows. It's really cool, but if I had the choice, always above ground.

How much does the temperature fluctuate when building massively and/or insulating?

The difference in energy consumption is roughly a factor of 10. That’s also not a problem if you accept the fluctuations and can endure it being colder or hotter at times. A simple outer shack without a power air conditioner and killer heating is great. Those who want to exercise in a well-tempered environment are better off with a different solution. It’s not about preventing this hobby. By the way, not only from a responsibility perspective, but also in the long run, better energy solutions pay off financially (which still interests many people in our prosperity bubble more than the impact of their own behavior).

Ideally, I would also like Bookmarks' solution: an extension as a cold winter garden (but without a glass roof), floor paved and with sliding doors to the terrace. Then cover the floor with rubber mats and place crash mats in the critical areas. In summer, you open the doors and can also do things on the terrace; for winter, you have infrared heating or a hot air blower. That heats up quickly, 15° is enough and it is only for a few hours in some months of the year. And so you also have a playroom for kids or an extra party room. A cold winter garden should be feasible for 1000 euros/m2. Warm would be significantly more expensive, at least as much as living space. I would set the ceiling height at 280 cm; that would be good for Olympic lifts or pull-ups. A bit higher and a climbing wall would also be possible.