Sometime around 1824, Notman joined his older cousin,
William Notman to train as an architect in the office of
William Henry Playfair in
Edinburgh prior to emigrating to the United States in 1831. He settled in
Philadelphia and first appears in the city directory as a carpenter then as an architect. He returned to Scotland in 1833 to move his mother and siblings to America. He met John Jay Smith who helped him obtain a contract to construct a building for the
Library Company of Philadelphia in 1835. Notman's design for Laurel Hill was selected over more experienced architects including
William Strickland and
Thomas Ustick Walter. The 1845
Athenaeum of Philadelphia was the first Italianate building in the city. Many of his designs for churches were dictated by the ideas of the
Cambridge Camden Society who suggested that
Anglican churches of the
Low church variety should be built in the
Romanesque style, while those of the
High church variety be built in the
Gothic style. until an argument over the terms of his contract resulted in his dismissal. In 1845, Notman designed a three-stepped office wing addition to the north side of the
New Jersey State House. Notman was also the architect of the highly influential
New Jersey State Lunatic Asylum in Trenton, New Jersey of 1847. This building was the first example of the
Kirkbride Plan in asylum design. In 1848, Notman was selected to design the
Hollywood Cemetery in Richmond, Virginia. The success of this project led to additional projects in Virginia including improvements to Richmond's Capitol Square. He also designed and built
Ivy Hall for Princeton University in 1847. In 1857, one of his last projects Notman died on October 3, 1865 His early death was reportedly accelerated by alcoholism. After his death, his architectural firm continued for several years under his protege
George Hewitt. A plaque was added near his gravestone in 1998 when Laurel Hill was designated a
National Historic Landmark. It reads: ==Personal life==