1817 Appointed architect to complete design work on the Old College, University of Edinburgh, on the basis of his proposals to complete the plans originated by Robert Adam.
The building was completed around 1831.

1818 Commissioned to design Dollar Academy: the original building which he created is now known as the Playfair Building
1818 City Observatory, Calton Hill
1820 East New Town (Calton Hill), Edinburgh (including Regent, Carlton and Royal Terraces), built between 1821 and 1860
1821–24 Royal Terrace, East New Town, Edinburgh only completed in 1860
1822 Commissioned by the Institution for the Encouragement of Fine Arts in Scotland.
The building was opened in 1826 and is now the Royal Scottish Academy Building, Edinburgh
1823 Royal Circus, New Town, Edinburgh
1824 in collaboration with Charles Robert Cockerell, designed an exact replica of the Parthenon which was to be built on top of Calton Hill as the National Monument, Edinburgh.
However, due to lack of investment it was never finished and became known as Edinburgh's Disgrace.

1825 Regent and Carlton Terraces, East New Town, Edinburgh, completed in the 1830s
1826 John Playfair Monument, (he was William Henry's uncle), Calton Hill, Edinburgh
1827 – 1828 St Stephen's Church, St Stephen's Place, Silvermills, Edinburgh
1829 Drumbanagher House (demolished), London Road Gardens, Edinburgh
1830 – 1832 For the Royal College of Surgeons of Edinburgh, Surgeons' Hall, Nicolson Street, Edinburgh
1831 Dugald Stewart Monument, Calton Hill, Edinburgh
circa 1837 renovations to Floors Castle, outskirts of Kelso, Scottish Borders
1846 – 1850 New College, Edinburgh
30 August 1850 Prince Albert laid the foundation stone of the National Gallery of Scotland.
adjacent to The Royal Scottish Academy.

1851 Donaldson's College, Edinburgh
1859 National Gallery of Scotland opened to the public two years after Playfair's death.
1817 Appointed architect to complete design work on the Old College, University of Edinburgh, on the basis of his proposals to complete the plans originated by Robert Adam. The building was completed around 1831.
1818 Commissioned to design Dollar Academy: the original building which he created is now known as the Playfair Building
1818 City Observatory, Calton Hill
1820 East New Town (Calton Hill), Edinburgh (including Regent, Carlton and Royal Terraces), built between 1821 and 1860
1821–24 Royal Terrace, East New Town, Edinburgh only completed in 1860
1822 Commissioned by the Institution for the Encouragement of Fine Arts in Scotland. The building was opened in 1826 and is now the Royal Scottish Academy Building, Edinburgh
1823 Royal Circus, New Town, Edinburgh
1824 in collaboration with Charles Robert Cockerell, designed an exact replica of the Parthenon which was to be built on top of Calton Hill as the National Monument, Edinburgh. However, due to lack of investment it was never finished and became known as Edinburgh's Disgrace.
1825 Regent and Carlton Terraces, East New Town, Edinburgh, completed in the 1830s
1826 John Playfair Monument, (he was William Henry's uncle), Calton Hill, Edinburgh
1827 – 1828 St Stephen's Church, St Stephen's Place, Silvermills, Edinburgh
1829 Drumbanagher House (demolished), London Road Gardens, Edinburgh
1830 – 1832 For the Royal College of Surgeons of Edinburgh, Surgeons' Hall, Nicolson Street, Edinburgh
1831 Dugald Stewart Monument, Calton Hill, Edinburgh
circa 1837 renovations to Floors Castle, outskirts of Kelso, Scottish Borders
1846 – 1850 New College, Edinburgh
30 August 1850 Prince Albert laid the foundation stone of the National Gallery of Scotland. adjacent to The Royal Scottish Academy.
1851 Donaldson's College, Edinburgh
1859 National Gallery of Scotland opened to the public two years after Playfair's death.
William Henry Playfair