The length of time it takes to complete a home extension can vary significantly depending on a number of factors, including the size and scope of the project, the complexity of the design, the availability of materials and labor, and the weather. In general, a small extension that involves only a few changes to the existing structure may take a few weeks to a few months to complete. A larger, more complex extension that involves significant changes to the structure or requires the addition of new foundations, walls, and roofs could take several months to a year or more to complete.

There are a number of steps involved in building a home extension, and each step can take a different amount of time. For example:

• Planning and design: This stage can take several weeks to several months, depending on the complexity of the project and the time it takes to get all necessary approvals.
• Preparation: This stage involves preparing the site for construction, including clearing the area, grading the ground, and installing any necessary utilities. This stage can take a few days to a few weeks, depending on the size of the project.
• Construction: This is the main building stage of the project, and it can take anywhere from a few weeks to several months or more to complete, depending on the size and complexity of the project.
• Finishing: This stage involves completing any final touches and installing any fixtures or finishes, such as flooring, paint, and cabinets. This stage can take a few weeks to a few months to complete.

Overall, it is difficult to give a specific timeline for a home extension, as there are so many variables that can affect the length of the project. It is important to work closely with a contractor to develop a detailed project plan and timeline that takes into account all of the necessary steps and factors that may impact the project.