A double-storey extension is a type of home improvement that adds two additional floors to an existing building. This extension can provide extra living space, such as additional bedrooms, bathrooms, or a larger kitchen. It is a popular choice for homeowners looking to increase their property's value without moving. These extensions can be designed to blend seamlessly with the original structure, enhancing the overall appearance of the home. Planning permission may be required, depending on local regulations, and it is essential to consider factors like building materials and architectural style to ensure a cohesive look.