Can't destroy my buildings as Engineer
Solution 1:
The current version of TF2 does not have this interface. You likely modified your own installation somehow. Pictures made a few minutes ago:
Edit:
After OP mentioning Gamepad controls, I googled a bit. According to this resource you can enable them only via the console by executing exec 360controller. Trying this one does indeed get the HUD as shown by OP. You can access demolish with left trigger, and build with right trigger. Use exec undo360controller to get your normal HUD back.