Depending on where you are in the world the type of garden you have will vary greatly. Different regions of the world have different biospheres and in order to see gardening success you have to adapt your garden to the external environment. In tropical regions the humidity and downpours of rain mean that having a thatched roof is popular as it can be quickly pulled over a garden to protect plants from rain.
In contrast, in the northern hemisphere you will find a very different type of garden. In Scandinavia you will find thickly walled gardens are popular and these have also been adopted in parts of the USA.
In the UK the type of building that you have in your garden varies greatly. In Kent you can find orchard houses, summerhouses will be found in Devon, in Yorkshire you will find potting sheds and in Scotland you will find holiday cabins. What is clear from this is that is what is built in a garden changes with the needs of the local people as well as the terrain.
In Europe initially gardens were used as a place for religious worship but in the 13th century they use mostly changed for the cultivation of vegetables and fruits. During this time a great many glass structures were created to optimise the growth of fruit and vegetables. After this change, the next was the construction of buildings in the garden as a demonstration of wealth. Towers, treehouses, and even temples were seen to be deconstructed in the gardens and estates of the wealthy.
It is clear that throughout history, buildings in the garden have been constructed to serve more than just a functional purpose. It is a room that explores the culture of the country and provides a space for work and play.