Five construction workers building the side of a gray building.
A group of construction workers were working on the side of the building.
" A group of construction workers" is a rephrasing of "Five construction workers".  It is normal for construction workers to be working on a building.
exists e1 s1 x1 x2 x3 x4.(n_side(x3) & Theme(e1,x3) & Actor(e1,x1) & v_build(e1) & of(x3,x4) & n_building(x4) & a_gray(s1) & Theme(s1,x4) & n_worker(x1) & of(x1,x2) & n_construction(x2) & card_eq_5(x1))
exists e1 x1 x2 x3 x4 x5.(n_building(x5) & n_side(x4) & on(e1,x4) & of(x4,x5) & Actor(e1,x1) & v_work(e1) & of(x1,x2) & n_worker(x2) & of(x2,x3) & n_construction(x3) & n_group(x1))