​The building was designed by Robert Saddler in the Ministry of Public Buildings and Works and opened by Her Majesty The Queen in 1964. His design incorporated many features from RBGE staff that relate to its function. The fittings and furnishings were provided by the Ministry’s Furniture Branch. The main contractor was W. & J. R. Watson, Ltd, Edinburgh.

The box-shaped frame construction is in reinforced concrete with floors and roof of slab construction. The building is faced in polished white terrazzo – a composite material of marble chips set in a matrix.

The cost of the building was £250,000 and it won a Civic Trust Award in 1966.

The original design features of note include:

• Large windows and skylight for ample natural light to aid study of material
• Climate control to maintain temperature (20 °C) and humidity levels (50% relative humidity)
• Structural support in the form of pillars to cope with considerable weight
• Supporting pillars hidden where possible within cabinets and bookshelves
• Scope for extension of the building to accommodate the growing collection

The building has been extended in 1997 and again in 2006 and offers further scope for extension at the western end.