Neighbor wants to plant a mountain maple

From my professional activity, I often see that a tree that becomes too large must eventually die in the prime of its life - and I find that terrible! They are cut down (replacement planting, planting obligation, felling ban or not, all of that needs to be regulated),
- for example, when an old woman becomes afraid of burglars or
- when the gardeners get old and can do nothing except mow the lawn or
- when the successor of the builder feels there is not enough light or
- when the tree's roots have reached the sewage pipes or
- when it lifts the access path or or or.

Relying on someone wanting to prune a tree against its natural growth form and height is problematic. Large common species are often cheaper to have than smaller growth forms. I think a tree is also a living being and should be chosen with capital investment so that it and the people there can live well together for a long time. Whoever is listed in the land register is probably quite indifferent to the tree.

Hopefully, there will be no big tree on call.

Best regards Gabriele

For example, prefabricated garages are prohibited,

Such inappropriate restrictions can jeopardize an entire development plan. Nonsense to the third power, prefabricated garages exist in the same volumes (also with pitched roofs if desired) and facade designs as onsite-built garages. This is not per se a different species.

thus our municipality has always also accommodated resettlers, then refugees decentrally and mixed in everywhere. Result: no ghettos, hardly any problems. [...] Only long-term rentals, no holiday apartments. No changing rentals.

I call that inconsistent: holiday guests are also much more socially compatible when they are scattered rather than concentrated like sponges in individual spots. By the way, I spent my nicest holidays in guesthouses run by widows whose house had become too big just for themselves. With guests they had income, a task, life around them, and could keep their familiar home. If someone does the same with a granny flat: who cares? — it only becomes problematic if a whole property is built up as a "party club" for Ballermann tourists. But that can be regulated just as discreetly and efficiently as a framework of permitted roof pitches.

Plot ratio 0.25. Maximum 1.5 stories, no knee walls. Roof pitch at least 25 percent.

That starts off so reasonably: plot ratio and number of stories. Together that is completely sufficient so that the floor area ratio does not also have to be specified. It is practically included already; it cannot get out of hand. But then it gets stupid: what you perceive as the external effect of the building is the eaves height. How far below the eaves an interior floor ceiling runs is of no concern to outside observers. If I can place a knee wall at eaves height, no one should begrudge me this luck, since it is no one's misfortune. So why? — because Ms. X got her shrubs included in the development plan in the municipal council, must Mr. Y now also have his knee wall mentioned?

But I can understand your shock. I’m also looking forward to my nice sunny lawn.

Apart from the fact that the lawn is happy when you don’t have to water it into a swamp only so it doesn’t scorch out in the sun: I’m just imagining the neighbor of the OP, from whose perspective the difference between the two garden definitions is only different in direction, but just as big: he "suffers" just as much under a neighbor who understands "garden" as "paving over with lawn." Just as a suggestion for a change of perspective.

Incidentally: if there is something "Japanese" in the planting plan, that rather indicates a different understanding of garden art than the cultivation of giant sequoias. Re-laaaax (ommmmm ...).

P.S. (because of Edit Timeout):

Pyramid roofs on square floor plans are allowed.

Such points in development plans can simply be removed without replacement: a pyramid roof is simply the result when you place a hip roof on a square floor plan. Then the house logically has no axis and the hip roof has ridge length zero from all directions. That it then has a different name, like "square" for the rectangle with equal side lengths, does not change the matter.

I agree with : to the emperor what belongs to the emperor, and the development plan should not contain more than necessary. The thing is supposed to regulate architectural coexistence, not to put the opinion of every garden gnome of every council member about the philosopher's stone on paper.

If the goal of a municipality is to offer plots of land with partly prime lake views for 115 per sqm in a region with over one million overnight stays per year and corresponding real estate price developments, in a touristically very strongly shaped environment, in order to enable locals to build affordably, one must prevent investors from big cities from misusing these plots for holiday rental purposes, even buying them up and covering them with such properties.
The thing with the knee wall probably aims to prevent disguised urban villas. This preserves a typical architectural image for SH, gables, bricks, bungalows, wooden facades, also gladly colorful, red houses have always been here. And it prevents something too massive from being built right in one’s face. Whether this is a bit exaggerated? Maybe. I welcome the holiday rental ban from experience in neighboring municipalities. Karsten

Such inappropriate restrictions can jeopardize an entire development plan. Nonsense to the third power, prefabricated garages exist in the same volumes (also with pitched roofs, if desired) and facade designs as locally built garages. They are not inherently a different species.

Whether they exist in indistinguishable quality, I do not know. To my knowledge, I have at least never seen such a one in nature (or it was actually so high-quality that you couldn't tell). Such quality is certainly not the reason to issue a ban. It’s about the quality that can be seen in abundance in every new development area, and that is horrible. Those things have the appearance of a plastered freight container, and I am glad not to have to see such things in my view in the future.

To enable affordable building locally, one must prevent investors from big cities from misusing these plots for vacation rental purposes, even buying them up and covering them with such properties.

This can be suitably secured in a less crude way, e.g. by tying short-term rentals to the landlord using 75% of the living space on the same property as their primary residence.

Whether they exist in an indistinguishable quality, I do not know. To my knowledge, I have never actually seen one in nature (or it was indeed so high-quality that you couldn’t tell).

That’s exactly right: the architecture of a masonry plastered flat-roof garage is exactly the same as if the thing, with the same exterior dimensions, offered more than 20 cm more interior width as a precast concrete room module or consisted of delivered pumice wood panels with the same wall thickness. Terrifying is sheet metal with stracciatella coating as plaster imitation, which I also don’t like. But this wording in the development plan is not appropriate – and can cause the plan to be rejected in its entirety.