The original Norman Keep was added to in 1581 and the new castle and old castle so skilfully joined and re-roofed that the two periods are now difficult to distinguish from the outside.
In 1700, the 1st Earl doubled the size of the building by adding a William-and-Mary style mansion house onto the Castle at a slight angle, built to the Earl's instructions by the well known mason, Thomson Caldwell.
The Victorian Wing was built in 1879-80, possibly by Alexander Crum, M.P. for Renfrew, who rented Kelburn from 1875 to 1886 from the 6th Earl of Glasgow, who spent most of his time in one of his other Scottish homes.
Kelburn brought together four of the world's leading graffiti artists from Brazil to work alongside Scottish talent, to create a unique burst of colour, embracing the walls and turrets of the south side of Kelburn Castle.
On a building steeped in rural conservative perceptions, this bold and shocking artistic statement received huge media attention, while challenging the public's understanding of both urban graffiti art and the British institution the building represents.
It is a project of contrasts and collaboration that bridges between cultures, rural and urban realms and unites two proud and very different cultures.
The project involved the artists and organizers living together in the Castle for approximately one month, documented by various forms of media. The artists had time to share and explore new ideas, from both sides of the equator, culminating in a one-off, giant piece of collaborative art.