In 1693 John Menzies, then owner of Cammo Estate, commissioned Robert Mylne to build a house. This is the first historical reference to a house on the estate, though it is likely that Cammo House was built on the site of a former house, or is, in fact, a substantial re-modelling of an earlier building.
The house was constructed to face south-east, and originally consisted of two main storeys and an attic storey, set over a raised basement. The main front entrance had a broken stone pediment doorpiece, dated 1693, and set on either side of this were two large windows. On the floor above, five large windows spanned the front of the house, with four similar windows spanning the sides of the house at each level.
The attic storey was completed at the front by twin crow-stepped gable-heads linked by a balustraded flat over the central entrance. At ground level, immediately below the main front entrance, a second doorway led into the raised basement. It is not clear what form of stair led up to the main entrance at this time. The external walls were of rubble stone construction, 0.75 metres thick, with sandstone margins to corners and openings. The house contained twenty rooms with fires, consisting of four public rooms, smoking room, billiards room, and fourteen bedrooms. There were also bathrooms, laundry, wash-house, kitchen, pantries, larder, two lofts, two cellars, and ample servant’s accommodation. Hot and cold water was laid on throughout the house.
The earliest record of improvements being made to the house occurred in 1718 when Sir John Clerk had the ground storey rendered on the outside with lime plaster. Presumably, the remainder of the house was also completed in this fashion. In 1724 John Hog, the then owner of Cammo, commissioned William Adam, the leading Scottish architect of that time, to re-design the house in a grand manner. This work was never carried out, but the proposed design is recorded in Adam’s renowned publication Vitruvious Scoticus.
In 1790 Charles Watson added a peron (external semi-circular stone stairway and balustrade) leading up to the main front entrance of the house, at a cost of £300. In 1794 a single storey pavilion was added to the east side of the house, and in 1814 an extensive three storey north-west wing was constructed, which considerably increased the size of Cammo House. Later in the 19th century, the east wing was also increased to three storeys, and the front of the house was altered by reconstructing the twin gable-heads into a continuous crenellated parapet. At the height of its splendour in the 1800s, when owned by the Watson family, Cammo House was a fine country mansion containing more than fifty rooms, and employed a total of nine gardeners, seven labourers, and twenty two domestic servants.
Between 1914 and 1920 a succession of tenants occupied Cammo House, while the absent owner, Mrs Maitland-Tennant, and her two sons were abroad. In 1940, shortly after the start of the Second World War, the Air Ministry requisitioned Cammo House. The Maitland-Tennants were obliged to leave Cammo House and took up residence in the nearby uninhabited golf clubhouse, which had been vacated by the golf club in 1929. During 1946, the Air Ministry relinquished Cammo House back to the Maitland-Tennant family, who took up residence once again.
In 1955 Mrs Maitland-Tennant died, and the entire estate was inherited by her younger son, Percival. Between 1955 and 1975 Percival Maitland-Tennant once again lived at the former golf clubhouse (which, in 1952, had been converted into a farmhouse), and was looked after and cared for by the tenant farmer and his wife. During this extensive period of time, Cammo House, already crumbling and dilapidated through neglect, lay empty and uninhabited except for a pack of about thirty dogs which Percival, an ardent dog-lover, had collected and accommodated in several of the once fine rooms. Percival spent each day at Cammo House sitting in an adjacent caravan, while, in turn, the various groups of dogs were fed, watered and let out for exercise.
In 1975 Percival Maitland-Tennant, the last private owner of Cammo House, died, and bequeathed the entire house, contents and estate to the National Trust for Scotland. By this time the house was in such a state of dereliction and filth that the National Trust could not afford to restore it, and the house was left empty for a couple of years while deliberations took place regarding its future.
On 23rd March 1977 the house was partly destroyed by fire, started by vandals, in which the entire north-west wing was totally engulfed, including the staircase and roof. A second fire occurred two months later in May, when the interior structures were completely burned out, leaving only the chimney stacks and outside walls standing.
In 1979 the estate and remains of the house (shell of original building) were gifted by the National Trust for Scotland to the then Edinburgh District Council in a feu charter, with a conservation agreement attached. In 1979 the house was considered to be in a dangerous condition, and was partly demolished. During this demolition work the late 18th and early 19th century extensions were completely removed, leaving no trace. In 1980 the final demolition to consolidate the ruins took place, when the walls were taken down to half the height of the first floor windows, but retaining the original 1693 doorway. This was considered to leave a safe ruin, and focal point of the estate. The demolished masonry is contained under sloping grassy banks which have been built up within, and around, the remaining ruin.