The European Historic Houses Association collaborates on a regular basis with the International Union of Property Owners, notably on issues relating to private estate and housing, including the revision of the energy
efficiency directives (EED,  EPBD and RED).

UIPI is a pan-European not-for-profit association comprising 28 organisations from 27 countries. Jointly, they represent more than 5 million private property owners and some 20 to 25 million dwellings. Founded in 1923, the UIPI aims to protect and promote the interests, needs and concerns of private landlords and owner-occupiers at national, European and international levels.

http://uipi.com/new/