In 1889, a new plan was announced for the building: a thick-walled brick tower, 16 stories high, devoid of ornamentation and suggestive of an Egyptian pylon. Brooks insisted that the building have no projections, for which reason the plan did not include bay windows, but Aldis argued that more rentable space would be created by projecting oriel windows, which were included in the final design. The Monadnock's final height was calculated to be the highest economically viable for a load-bearing wall design, requiring walls thick at the bottom and thick at the top. Greater height would have required walls of such thickness that they would have reduced the rentable space too greatly. The final height was much dithered over by the owners, but a decision was forced when the city proposed an ordinance restricting the height of buildings to . To protect future income potential, Aldis sought a permit for a 16-story building immediately. The building commissioner, although "staggered by the sixteen story plan", granted the permit on June 3, 1889.