to implement energy saving have often implemented in the end is difficult to how hiter to achieve meaning that they are possible without extremely extensive renovation work potential for energy
Easy to implement energy saving measures have often been implemented in the past and it is difficult to estimate how high the easy to achieve (meaning that they are possible without extremely extensive renovation work) potential for energy savings is.
to implement energy saving have often implemented in the and it is difficult to how high the to achieve (meaning that they are possible without extremely extensive renovation work) potential for energy is.