Columbia subject headings:
Architecture and energy conservation--Europe, German-speaking.
Architecture, Domestic--Europe, German-speaking.
Architecture--Europe, German-speaking--History--21st century.
Dwellings--Energy conservation--Europe, German-speaking.
Harvard subject headings:
Architecture and energy conservation
Architecture, Domestic--Energy conservation.
Housing, Single family--Energy conservation--Austria.
Housing, Single family--Energy conservation--Germany.
Housing, Single family--Energy conservation--Switzerland.
Princeton subject headings: