Building design (12)
I believe the answer is:
architecture
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">building design</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for architecture that I've seen before include "Structure of buildings" , "Structural design" , "Branch of design Goethe called frozen music" , "Style of building design" , "Art of designing buildings etc" .)