Peffermill is an altered 17th century tower house of three storeys and a garret, with a semi-circular stair-tower in the re-entrant angle.
The entrance is at the foot of the stair-tower and leads to the wide turnpike stair and the partly vaulted basement. The basement contains a kitchen with a large arched fireplace. The hall on the first floor has been sub-divided and the house has been much altered inside.
The property originally belonged to the Prestons of Craigmillar but was sold to the Edgars who built the house. It later passed to the Osbornes, then to the Alexanders. The house is in good condition and still occupied.