minimum energy performance requirements for buildings or building units, in order to achieve a "cost-optimal level" (the energy performance level which leads to the lowest cost during the estimated economic life-cycle) ;
ehitiste või ehituselementide energiatõhususe miinimumnõuded, et saavutada kulutõhus tase (energiatõhususe tase, millest tulenevalt saavutatakse eeldatava majandusliku eluea jooksul madalaimad kulud);