To create a garden structure, greenhouse, or shed, you must apply for householder planning approval if the total amount of ground covered is larger than 50% of the entire land around the home. It will be erected on the grounds of a historic structure. If the application is refused, then an appeal can be made to the same authority. The decision on the appeal is final. Building projects like these require significant expertise and specialized equipment, so unless you have adequate experience with large structures that are hard to maintain, it's best to hire a professional architect or engineer. These people can help you plan out your project effectively and avoid any possible complications during construction. The rules regarding building permits for gardens are different in most cities across the United States. Before you start work on your project, make sure that you find this out from the local government agency in charge of building regulations. Also check whether there are any special requirements for historic buildings. In some areas, it's illegal to build within the area of a city without a permit. Other cities may have restrictions on how high you can build on certain properties. Still others may limit the number of stories that you can construct. Make sure that you know the laws in your city before you begin work on your project so that you don't face any problems after it's finished.