Civil Engineering Reference
In-Depth Information
An important amendment made in the latest version of the EEWärmeG is the
role model of public buildings and the expansion of the definition of 'heat', now
also considering 'cold'. Special requirements for public buildings undergoing
major renovations are stated in Articles 5a of the law. In case of a major reno-
vation with the use of gaseous biomass, a minimum share of 25 % of the heating
and cooling demand of the buildings has to be covered by the renewable source.
For the deployment of all other renewable sources, the necessary share is 15 %.
All building owners obliged to fulfil the requirements of the EEWärmeG are
also allowed to alternatively implement one of the following measures:
• Exhaust heat: If exhaust heat pumps are used, 50 % of the heating demand has
to be covered. If a ventilation system with heat recovery is used, a heat recovery
rate of at least 70 % and a coefficient of performance (usable heat/electricity
input) of 10 have to be achieved.
• Combined heat and power (COP): The COP plant has to be highly efficient,
which means that the generation needs to result in primary energy savings
compared to a reference situation;
• Energy saving measures: The maximum allowed primary energy demand and
insulation requirements according to the actual EnEV have to be reduced by at
least 15 %. In new public buildings, the average heat transfer coefficient has to
be reduced by 30 % and in the case of a major renovation by 20 % compared to
the requirements of the EnEV.
• District hot or cold temperatures: Allowed if a significant share of the hot or
cold temperature is generated from renewable sources or a minimum 50 % by
exhaust heat or CHP or a combination of all.
The Federal States are allowed to set higher obligations (see the following
example of Baden-Württemberg).
Example from Baden-Württemberg—EEWärmeG-BW
One interesting transposition of the requirements on national level has been made in
the Federal State of Baden-Württemberg. The EEWärmeG-BW already entered
into force one year earlier than on national level (1 January 2008). Since January
2010, the obligation to use renewable energies in buildings has even be expanded to
existing buildings, and thus, Baden-Württemberg was the first and still is the only
Federal State where renewable energy systems have to be considered in the case of
a refurbishment of residential buildings, when the heating system is exchanged. In
this case, at least 10 % of the heating demand has to be covered by renewable
energies (depending on the specific technology). Also, the EEWärmeG-BW offers
the opportunity to use alternative measures. Deviating from the options on national
level, in Baden-Württemberg, a ventilation system with heat recovery is not con-
sidered in the law; instead, a photovoltaic system can be installed.
