Industrial park seeks property management solution (especially operating cost accounting)

We are a provider of commercial space in an industrial park and are looking for relatively simple software that can manage our 18 buildings, 30 tenants, and 40 rental agreements. All buildings are located on one property. It would be good if costs applicable to all buildings, such as drinking water and electricity, could be entered once globally. We do our own accounting in DATEV, so we don't need an accounting module. We have commercial and private tenants with and without VAT. The primary goal is simple and error-free utility billing. A DATEV interface would be ideal, but is not a requirement.

One software workstation is required.