Yes, draftier is in the scrabble dictionary.

What does the word draughty mean?

/ˈdræf.t̬i/ A draughty place, especially a room, has currents of unpleasantly cold air blowing through it: a draughty old house. Wind & winds.

What is the bracing?

Bracing consists of devices that clamp parts of a structure together in order to strengthen or support it. Bracing consisting of a rigid steel frame prevents the structure from moving. ... Bracing consists of devices that clamp parts of a structure together in order to strengthen or support it.