Is summer heat protection in new buildings *mandatory*?

However, afterwards I was somehow concerned and inquired by email. The lightning-fast response was: "Summer thermal protection is a must according to DIN4108 part 2 and is calculated by [...]. It shows which rooms must be equipped with shading."

But is summer thermal protection also legally or otherwise mandatory, or can we do without it without being sanctioned in any way – in the worst case by mandatory retrofitting?

If summer thermal protection is a somehow sanctionable must: does it have to be an external thermal protection? My wife cannot live without curtains, so we already have internal thermal protection – of course worse than external, but present. We will not retrofit an air conditioning system...

At least if my wife keeps the bedroom windows closed during the day, which unfortunately is not always the case. The children have so far survived without serious difficulties, in summer it just gets really hot for a few days, it is what it is.

I don't want roller shutters because I know from my parents’ house the manually operated blinds, where either the strap now looks terrible (torn) or the blinds eventually partially get stuck or break otherwise. I don’t want to have more devices to maintain in/on the house – and especially with the internal and plastered or wallpapered roller shutter boxes it will be a big "fun"/huge effort in case of a defect with the strap/motor/radio receiver/shutter or anywhere else – and that with 19 or at least 14 windows...

However, my wife could get used to shutters, which can – I fear in red – also be a design element.

I will take a closer look at venetian blinds right away, maybe they are also significantly cheaper...

Many quotes, I’ll keep it short: We also didn’t want to spend money on it, then had to sign with the architect for the records that we were instructed. Our office extension, a cheap building, also has thermal protection on the south windows. So apparently this thermal protection regulation exists. Just google it. We then decided to take it, cheap plastic roller shutters, everything else from the inside is useless or outside more expensive. And they are not electric either. We are glad we decided on roller shutters. We have many large windows to the south and west. Upstairs we will probably get a fan now, if we were to build again, I would install an air conditioning system in the bedrooms facing south and west. Our office extension: a catastrophe regarding sun and thermal protection. The heat accumulates, you can do nothing. I’ll put it this way: to do without it is like installing only cold water with a boiler in the bathroom. In today’s new build, the savings tap in this area is definitely a design failure. P.S. Internal thermal protection is new to me – it doesn’t even exist, does it?!

P.s. An internal thermal insulation is new to me - it doesn’t even exist, does it?!

No, it doesn’t. Everything that is on the inside only blocks solar radiation in the sense of “things fading.” The energy is already in the room and stays there (apart from negligible amounts reflected by reflective blinds or similar). Not even covering the windows with aluminum foil brings any noticeable effect. Tried everything last year. Then it’s just dark and hot instead of bright and hot.

Alternatively, one can also:

a) plan the house accordingly. For example, as suggested, with few/smaller windows facing south/west. This might possibly reduce the living quality.

Or b)
plan a large roof overhang (for high sun) in combination with suitable planting (for low sun). Depending on the floor plan, maybe a covered terrace around the corner, so that perhaps two large patio doors are already covered.

I also had roller shutters installed everywhere; besides thermal protection, they also provide protection against unwanted views.

because I know the manually operated blinds from my parents' house,

I don't think you can compare that with modern roller shutters. With electrical systems, you don't have straps. Do you even have to access the boxes from the inside nowadays? I would definitely recommend sun protection to you. As my predecessors have already said: you can't get the heat out anymore and it heats up very quickly. Even in winter, on sunny days, we need sun protection.

Alternatively, one can also:

a) plan the house accordingly. For example, as suggested, with few/smaller windows facing south/west. This might reduce the living quality.

Or b) plan a large roof overhang (for high-standing sun) in combination with suitable planting (for low-standing sun). Depending on the floor plan, maybe a covered corner terrace, so that perhaps two large terrace doors are already covered.

I have also installed blinds everywhere, which in addition to thermal protection also provides protection against unwanted views.

As far as I can tell, the original poster has no desire to invest time or money in maintenance. The measures cost money and maintenance? So in 5 years no one has come for the blinds.

We have no revision option from the inside for [Raffstore] and roller shutters. I wouldn't even know if that is still compliant with the Energy Saving Ordinance, since it represents a significant thermal bridge. Everything is accessible from the outside, which is not a problem at all in case of emergency.