As master of work for Edinburgh burgh council, MacDowall measured quantities and made contracts with masons, including works at Newhaven and the conversion of a part of St Giles Kirk into a new Tollbooth.
As master of work for Edinburgh burgh council, MacDowall measured quantities and made contracts with masons, including works at Newhaven. After the reformation in 1560, MacDowall was excluded from the town works which recommenced with the conversion of a part of St Giles Kirk into a new Tollbooth.