Here, the net return is calculated as follows:
$$\text{net return} = \frac{(\text{basic rent}
- \text{running costs}) * 100\%}{\text{purchase price incl. additional costs}}.$$
In the above formula the basic rent as well as the running costs are provided per year.
The running costs for the property per year consist of the non-transferable
operating costs plus the maintenance fee:
non-transferable operating costs per year
+ addition to the maintenance reserve per year
running costs per year
The additional costs for the purchase consist of the real estate agent's
provision in case, the notarial charges, the land register costs,
as well as the transfer tax:
real estate agent's provision
+ notarial charges and costs for the land register
+ transfer tax
additional costs
In the calculation of the net return on investment
the individual costs such as the financing or reparation costs
are not taken into account.