Stairs and roofs

Fig. 1: Drawing of a stair SRAC (blue) along the wall SQRX : Draw diagonal d, choose A to define the length of the steps, connect A with VP1 to create B, draw vertical through B to create C : SRAC (blue) defines the stair.

Note : The side-lines defining the stair WPTU converge to a Vanishing Point (VP)  VPS located on a vertical line to the Horizontal Line (HL) through VP2.

Fig. 2 :  Note that the front lines of the roofs converge to VRP. VP1 and VPR define the Vanishing Line (VL) of the roofs.