[1] The oldest part, a Scottish vernacular L-plan tower house, dates from the early 17th century.

The term "Inch" derives from the Scottish Gaelic innis which can mean either 'island' or 'a dry area within marshland or a river meadow'.

[4] The lands of Nether Liberton on which Inch House now stands were granted to the monks of Holyrood Abbey from the mid-15th century.

[9] A supporter of the Covenanters, he died in 1650 from wounds sustained at the Battle of Dunbar where he fought against Oliver Cromwell's army.

A large doorway was built in the internal angle of the ‘L’ to form a grand entrance leading to a wide spiral staircase.

Sir Robert Gordon Gilmour (1857–1939) inherited the house and in 1889 married Lady Susan Lygon (1870–1962), and they planned a major series of internal and external alterations which took place between 1890 and 1892.

They commissioned the leading historical architectural firm MacGibbon and Ross, who had published a major historical survey of Scotland's towers and stately homes entitled The Castellated and Domestic Architecture of Scotland from the twelfth to the eighteenth centuries,[13] They were asked by the Gordon Gilmours to make the entrance to the house grander and more impressive and to make the house more comfortable for late 19th century living.

The modernisation and embellishment included enhancing the main entrance by creating an elaborate pilastered and pedimented porch, above which is inscribed the Gilmour family motto ‘Nil Penna Sed Usus’ ('the practice not the penmanship').

Externally the west wing was made to look grander with the addition of angle turrets and dormer windows.

[1] There was further major expansion of the building at this time with the addition of a north wing which resulted in the formation of an inner courtyard.

The large doorway, created on the north side of the tower at the same time, is now internal as a result of later additions.

The lintel carries the date 1617, the motto "Blessed be God" above the initials James Winram (IW) and his wife Jean Swinton (JS).

There are smaller rooms on the second and third floors from where a turret stair leads to a roof area which commands panoramic views.

On the west external wall above two windows are the initials 'IW' and 'IS', again representing James Winram and Jean Swinton.