As chief government architect he was responsible for many of the federal buildings constructed in this period.

His son John Albert Ewart was an acclaimed Ottawa architect.

As federal architect he oversaw the design and construction of several buildings at the Central Experimental Farm including the Dominion Observatory, Carling Avenue in 1902; Chief Astronomer's Residence, 1909; and the Geodetic Survey Building, 1914.

structure features a façade, flanking towers and a low-pitched gable roof; it projects a solid, fortified appearance stone structure has a copper hipped roof.

His son John Albert Ewart was also a prominent Ottawa architect.