I would not allow it, there are a number of problems:
- Has a site/height plan already been created for your property? How is that supposed to work when piles of earth and the raised crane setup area cover the actual terrain?
- Crane on your property = construction site that must be reported, meaning you have to notify the municipality of the start of construction, which then reports it to the BG Bau, and so on.
- No matter what, as the owner of the property you are responsible; you cannot simply transfer this to someone else. The formal procedure is always: you are liable to the injured party and, in case of damage, you can then approach the external construction company, the crane operator, etc., to get your money back. --> Good luck
- Are you sure that the municipality or, for example, the BG Bau will be 100% satisfied during an inspection with the securing of the crane, e.g., fencing, barriers, etc.? What if not?
- Then there is the delay issue, your construction start is too close. In our residential area, shell constructions were sometimes delayed by months due to construction defects or the bankruptcy of a subcontractor. For example, one had to wait 8 weeks after completing the ground floor for his precast ceiling elements because, for whatever reason, the statics had to be redone and new precast ceiling elements had to be ordered... (current waiting time at the plant)
Be polite and justify it with the surveying work and an allegedly advanced construction start. The potential for a neighborhood dispute over the crane on your property is much higher than the risk of annoyance from not allowing it. Instead, offer him that they can temporarily store building materials such as pallets of stones, reinforcement mats, roof beams, and the like, items that can be quickly cleared away if needed. No piles of earth! What if your neighbor’s funds run low towards the end and he realizes how expensive earthworks or transport & disposal really are... don’t do it.