Most commercial leases contain terms that require tenants to pay additional rent. Additional rent is usually a share of the costs and charges incurred to operate the property. These costs can include municipal taxes, insurance premiums, repair and maintenance costs and common area utility charges. In any given year, these charges change and fluctuate. Landlords often provide an annual estimate which tenants pay subject to a year-end reconciliation. Lease terms governing these types of costs are often general in nature because it is not possible to contemplate all the variables and, at the same time, have the same additional rent provision apply to all the tenants in a commercial building.
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Usually gas and electricity are included in the additional rent costs (or Nebenkosten) and organised by the landlord, but this is not always the case. Monthly combined costs for gas, electricity and water are typically about 150 Euros per month for a one bedroom apartment, and 300 Euros per month for a three bedroom apartment. Note that in "apartment for rent" advertisements, Nebenkosten will often include the above utilities and internet, trash disposal, basic insurance and cleaning of communal areas.
You will receive a Nebenkostenabrechnung from your landlord at the end of each year detailing your actual gas and electricity usage, and in some cases may be asked to pay the difference or be refunded.
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"bill for additional rent" :http://goo.gl/c8FTdR