The front of the guinea pig cage should have a door with a wooden frame and wire mesh attached, to allow light and air into the hutch. The door usually covers two thirds of the front of the hutch with a smaller door covering the rest of the front. This will give the owner easy access to the hutch for every day jobs such as feeding and cleaning.
If your guinea pigs are kept in their hutches in a shed then windows should be opened for airflow and wire chicken mesh can be placed over the back of them to make the shed safe from predators such as cats.
Sleeping Area
The covered part of the guinea pig hutch is not absolutely necessary as they do not make nests as a rabbit would in their hutch, however it provides them with a more restful place within their housing and its here you can place heaps of bedding material such as hay or soft straw.
Security
Some guinea pig hutches are fitted with a solid wooden panel, the same size as the mesh opening of the hutch, which can be fastened up over the cage at night or espacially in bad weather. If this is fitted remember to drill holes into it so air can flow throught the guniea pigs hutch. This is fitted for added security.