Structural framework (7)
I believe the answer is:
chassis
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">structural framework</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 chassis that I've seen before include "Vehicle structure" , "Mounting" , "Bodywork" , "Vehicle's base frame" , "an estate may be built on it" .)