Floor plan design with cooling load calculation

Put bluntly, it can make a big difference whether I have to heat with ~10 W/m² in the passive house in the depths of winter or if in midsummer >100 W/m² (direct) solar radiation heats up the house.

That would then clearly not be a passive house in any case.

As far as the calculation of the cooling load is concerned. Practically, it is not about how much less I have to heat due to solar radiation in winter, but how much I have to cool additionally in summer in order not to exceed a certain room temperature throughout the day.

At its core, with a centralized controlled residential ventilation system with heat recovery, you ensure that the temperature can remain constant even though the sun moves around the house. And a storage system must also play a role. Passive houses are a planning field that cannot be grasped in a rush. Nevertheless, the calculation is not magic. One thing is certain: as long as you have not understood that the methodology of climate constancy calculation cannot be divided into a separate heating or cooling load calculation and that the temperature number line is continuous and level, you should limit your involvement in the house design to your design wishes and leave the technical stuff to the professionals. Even I do that—not despite understanding it, but because I understand it. I am a construction consultant with broad basic knowledge, but even an orthopedist leaves surgery to the specialists in that field. Trust in other people's expertise is a very important building block; as a layperson, you will not be happy with the self-imposed demand to have the fullest universal insight throughout your life as a builder.

First of all, thanks for the numerous responses and comments.

Why don’t you thank us with an insight into your project and your planning practice level.
By the way, my profession is to coach builders in communicating their wishes to the project-related specialists—often scribbled down on a scrap of paper. Many of my clients try their hand as house planning gamers, but NONE with weak amateur-compatible specialist software. And none of them have inferiority complexes about going into architectural discussions as acknowledged laypersons. At least no longer after we have met. There are certainly colleagues of my kind with a passive house focus as well.

Why should a house with a max. heating load of 10W / m² not be a passive house (cf. Wikipedia)? With a larger window area facing south, on the other hand, at least in summer even with partial shading, 100W / m² can easily be achieved.

In general, it is indeed true that the thermal load depends on many factors, some of which have already been partially mentioned here. But precisely for this reason, the temperature profile cannot simply be estimated with pen and paper.

My concern is therefore to be able to discuss in an exemplary and well-founded manner with a professional planner what effort would be necessary for wall or ceiling cooling in order not to exceed 19°C year-round and in the future in the bedroom.

to not exceed 19°C in the bedroom all year round and in the future.

then show your floor plan, if the bedroom is on the upper floor and faces south, the planning mistake will cost you a lot of cooling capacity. Our bedroom in the bungalow faces northeast and achieves any desired temperature with a 2000W split air conditioner cooling capacity. Although we never go down to 19° when it is 28° outside in tropical nights.

The floor plan does not yet exist in detail. However, in accordance with the idea of a passive house, there will be a predominantly southern orientation with extensive shading options there. Conversely, the bedroom is expected to face east in particular, in order to benefit mainly from the morning sun. I would like to avoid a split air conditioning unit as much as possible, among other things because of the noise it generates. With thermally activatable drywall panels, such as those from Uponor, a maximum of about 60W / m² of heat is dissipated. This is of course much less than with a split unit, but that is precisely why the question arises as to how far one can get with this, especially for longer-term / continuous cooling of such areas. Naturally, with surface cooling, humidity must also be kept in mind, but this is more a matter for the (already existing) ventilation.

Why should a house with a max. heating load of 10W / m² not be a passive house (cf. Wikipedia)? With a larger, south-facing window area, on the other hand, at least in summer, even with partial shading, 100W / m² can be easily achieved.

So you spoke and still speak of having to spend energy at ten times the heating effort at another time to prevent unwanted heating, and that does not sound like a passive house, but on the contrary, like generous process energy being shuffled around.

In general, it is of course true that the thermal load depends on many factors, as have already been partially named here. But exactly for that reason, the temperature curve cannot simply be estimated with pen and paper.

There was no mention of pen and paper, but of not having to use another, separate calculation tool in the opposite direction of effect. Although, yes, pen and paper for side calculations, of course ;-)

My concern is therefore to be able to discuss exemplary with a specialist planner on a sound basis what effort would be necessary for wall or ceiling cooling in order to not exceed 19°C in the bedroom all year round and also in the future.

And for that, you want to simulate various dozens and dozens of house designs by the Infinite Monkey method until one brings you the desired room temperature (which you do not understand why)?
I consider it more clever that you deal with the basics and the (inter)actions of the involved elements and systems.

The naive idea of a measured value and dimensioning of the counteraction overlooks the (inter)action of various sluggish participants.
But you are in the best company: according to the same misunderstanding principle, political economic control also does not work ;-)

The specified 10W / m² refers to the maximum heating load per living area, whereas > 100W / m² refers to the expected heat gain per (partially shaded) window area in midsummer. The latter therefore varies greatly and cannot be directly compared 1:1 with the previously mentioned heating load.

The "generous process energy" for removing heat from individual rooms is thus also very variable. Additionally, this can behave neutrally regarding primary energy demand, for example via a photovoltaic-coupled heat pump or a ground probe. In this respect, I see no general contradiction to the idea / concept of a passive house.

In the modeling, it is not about experimenting with different floor plans. Rather, it is about questions such as the approximate influence of different window areas and orientations, their proportional shading, or the exact choice of glazing.

Exemplary, therefore, a tool of the kind shown in the screenshot of the [GEQ], but for the German market and local climate zones.