15.4.3:
An impact absorbing structure must be fitted in front of the survival cell. This structure need
not be an integral part of the survival cell but must be solidly attached to it.
No part of this structure may lie more than 525mm above the reference plane.
It must have a single external cross section, in horizontal projection, of more than 9000mm² at
a point 50mm behind its forward-most point. Furthermore :
a) No part of this cross-section may lie more than 250mm or less than 135mm above the
reference plane.
b) The centre of area of this section must be no more than 185mm above the reference
plane and no less than 750mm forward of the front wheel centre line.
Edit: Already been posted.
This is what I have so far for the volumes allowed for bodywork for 2014 (not including anything else like the 75mm radius areas etc), for 3400mm wheelbase and where the front of the tub is in line with the FWCL (doesnt have to be, moving the front of the tub rearwards gives you a less severely sloped area for the nose cone).
There are some other interesting changes, like the fact that the curved edges of the floor have to have a constant curvature - That will surely have some effect on the area around the floor leading edge. Also by my interpretation the top of the tub can't be U-shaped (flat or convex only).