Heavily overgrown property - what is the best way to proceed?

The lady from the office has not mentioned anything about replacement planting yet. For her, a possible reason in favor of approval is if the tree to be felled is in the way of a construction project. According to today's inspection, this is the case for at least 9 out of 10 trees. Or if there is a danger coming from it. This is also the case for 2 trees.

What will be interesting is the cost of these permits. It is clear that felling can only take place in October, and the property is not yet ours. Today I sent the owner the current pictures, and tomorrow I will clarify with the lady from the office what the permits will cost or when she would like to inspect the site.

So if you have a rough idea: removing 5 trees > 4 meters and trunk circumference >60cm including roots costs 1,800 EUR with a landscape gardener, approval from the environmental protection office <100 EUR. Replacement plantings must be carried out, "buying out" of them is expensive. If it is the same for you and you don't want to plant 10-20 new trees on your property, please ask what the buyout of replacement plantings costs with you.

In Berlin, you almost always have to carry out the replacement planting.

I would also suspect that. From the tree protection ordinance here: "As a replacement planting, for every started meter of trunk circumference (measured at 1 m height above ground level) of the removed tree, a native tree according to Appendix 1 'List for the replacement planting of native trees' with a circumference of 20 cm at 1 m height above ground level must be planted and maintained at the owner's expense. If the tree does not grow, the replacement planting must be repeated.... .... .... The amount of the compensation payment is based on the average value of the trees according to the list of native trees (see Appendix 1 to § 8 para. 2), with which the replacement planting would otherwise have to be carried out (see paragraphs 1-2) plus the planting cost flat rate of 30% of the net purchase price."

Thank you very much for the examples.
The federal state is Brandenburg.

The environmental protection office is not responsible because there is a separate statute. As far as I remember, there is also something about replacement planting. Well, we'll see what comes of it.

60cm is not much, you will probably need some permits.