How to keep an overview of all maintenance (renovation) tasks on the house?

How do you intend to find an appropriate target group if not here in the forum? There are plenty of apps on the market that already cover everything you offer. Some have already been mentioned here in the thread.

Examples - Clean gutters - Clean trash bins - Treat/paint wooden frame windows - Clean roller shutters - Check/clean drains - Clean birdhouses - Check basement walls for moisture -....

In your list, I only see two points where I see an advantage in doing this proactively. Everything else is done as needed. For example, in my entire life, I have never cleaned a trash bin. Why should I? It is emptied every 14 days. And if there happen to be maggots in it during summer, that takes care of itself after the next emptying.

In the basement, you certainly spend some time occasionally, so you should notice at some point if it is too damp. Or do you start emptying entire rooms to check the walls precisely? Hardly.

That's something you notice. When the performance decreases, you have to take action again. I wouldn't necessarily schedule it.
You could also simply put a sticker on the front of the device with the date of the last cleaning. Then you see it every time you use it. If someone still ignores that, an app won't help them either.

That might work very well for you, but I would hide the sticker after a week at the latest and never get around to it. Every person is wired differently, you need to look beyond your own perspective a bit. Besides, the performance declines gradually and you only notice it much too late.

I write all tasks into my to-do lists and schedule them so that everything gets done appropriately. That way, I can focus on the important things and have a completely clear head. I hate having to keep things in the back of my mind, and for my quality of life and satisfaction, that was a big step. Overall, I live much more carefree like this.
Additionally, my partner is always informed this way and we can share the tasks well. That doesn't work if everything happens only in one head.

So, I descaled my coffee machine for the first time the day before yesterday after 3.5 years, never cleaned it with those nasty tablets. It works like on the first day.

But the coffee will certainly not taste as good as on the first day. After half a year without cleaning, we already notice a clear difference. Take it completely apart and clean the brewing unit. You will be amazed at how different the coffee tastes then. By the way, all the fats and coffee residues can also mold inside the machine. Then it not only becomes disgusting but also unhealthy.

I'm getting increasingly fed up with this over-optimization of life. Sometimes things have to go wrong – that's the spice of life – you only gain experience through fails :D

And maybe someone will accidentally cultivate a noble mold in the coffee machine that then takes this divine drink to the next level ;)

This constant over-optimization of life is really getting on my nerves.

Me too, the world is getting sicker and sicker, rules for rules, and I totally agree with and
We have been living in the house for 9 years and every September, we independently remember to call the heating technician for maintenance. Everything else works well "as needed" or by usage (e.g. attic). The KVM is regularly cleaned by us, mostly when the kitchen is cleaned and there is time. We don’t need an app or calendar to tell me when the oven is dirty and should be cleaned.

Away from the kitchen: those who enter the garden more often also take a look at the facade or the roof. Even when cleaning the windows (this also works without a tool) you can discover something. And so on. I don’t really know what I would need to schedule there. If not today, then tomorrow. And gladly, if the weather permits.
Let me put it this way: whoever cleans their clean car might have missed a beat or has no other hobby. But it’s about cleanliness – also in the house, which some like to do on a fixed day of the week. Not me, many others orient themselves according to need and when there is time. The note in the brain works quite well according to priority.
Whoever turns into a slave to their house and garden and chases appointments probably has too little else fulfilling in their life.

A house is still meant to give its family a home where one can develop. That means: hobbies, joint activities, mental and physical development as desired.

Any calendar puts you under pressure, and that can make you sick.
Where I can’t escape it is work. But even there the calendar is patient, it has to be. Flexibility is contemporary and necessary.
And this also applies to problem houses like old properties. My parents sometimes have drainage problems in the kitchen: they deal with it when they notice that the drain is a bit slower. That doesn’t require a tool, nor a calendar. And yes, the calendar: it still exists: everything important like doctor’s appointments, school performances, weddings and birthdays at one glance. For forgetful people, there is even room for the heating technician in September.

I think it’s a pity that people think they have to subordinate themselves and their property. That is exactly the path you are on right now.

The last few years have only been filled with work, family and renovation etc.

That’s called life, and that’s a good thing, enjoy it.

Sure, I could also sit down for a morning and open an Excel sheet,

But you don’t have to.
I know there are people who need structured routines and even schedules to feel comfortable and to get anything done in everyday life. But that is specific and if it has to be that way, it is a niche target group. Because that also includes brushing teeth and everything that is normal for many people to think of independently. Possibly the professional group of controllers also falls into this target group.
But anything else can be noted somewhere from O to O, start of the quarter or in month X or season period. And if it is postponed or forgotten, there is no damage in sight right away. Then you make a note for next year.
In that respect: I’m out (fitting for the tool, quote from Höhle der Löwen)

Me too, the world is getting sicker and sicker, rules for rules, and I fully agree with and We have lived in the house for 9 years and every September we independently remember to call the heating technician for maintenance. Everything else works fine "as needed" or by usage (e.g. attic). The KVM is regularly cleaned by us, usually when the kitchen is cleaned and there is time then. We don’t need an app or calendar that tells me when the oven is dirty and should be cleaned. Away from the kitchen: whoever enters the garden more often also looks at the facade or the roof. Even when cleaning windows (which also works without a tool) one can discover something. Etc. I wouldn’t know what I would have to schedule there. If not today, then tomorrow. And gladly, if the weather allows. Let me put it this way: anyone who cleans their clean car may have missed the point or have no other hobby. But it’s about cleanliness—also in the house, which some like to do on a fixed day of the week. I don’t, many others orient themselves according to need and when there is time. The note in the brain that is created at the top works quite well according to priority. Anyone who makes themselves a slave to their house and garden and chases after appointments probably has too little else fulfilling in their life. A house is still there to give its family a home where one can develop. Meaning: hobbies, joint activities, mental and physical development as desired. Any calendar puts one under pressure, and that can make you sick. Where I cannot escape it is work. But even there the calendar is patient, it has to be. Flexibility is contemporary and necessary. And that also applies to problem houses like old properties. My parents occasionally have a drainage problem in the kitchen: they deal with it when they notice that the drain is a bit slower. No tool or calendar is needed for that. And yes, the calendar: it still exists: all important things like doctor’s appointments, school performances, weddings, and birthdays at a glance. Then even the forgetful have room for the heating technician in September. I find it a pity that people think they have to subordinate themselves and their property. You are currently on that path. That is called life, and that’s how it’s supposed to be, enjoy it. But you don’t have to. I know there are people who need structured routines and even schedules to feel comfortable and to achieve anything in everyday life. But that is special and if it should be so, that is a niche target group. Because that also includes brushing teeth and everything that is normal for many to think about independently. Possibly the professional group of controllers also falls into the target group. But everything else can be noted somewhere from O to O, beginning of the quarter, or in month X or season period. And if it is postponed or forgotten, there is no damage in sight. Then you just make a note for next year. So: I’m out (fitting for the tool, quote from “Höhle der Löwen”)

It is great to see how diverse the approaches to property management can be! Everyone has their own way of organizing their home, based on individual needs and priorities. While some prefer a flexible approach and handle tasks as needed, others may rather appreciate a structured approach with a fixed plan. In my opinion, neither is negative. No black or white, no one size fits all, but depending on each individual and their current life phase. Homerockr is not aimed at providing a one-size-fits-all solution, but a support for those who see the benefit in it. So for those who want it easier to manage their property without restricting flexibility and joy of life. It is not for everyone, and that is okay. Thanks again for your perspective and your honest thoughts on this topic.