The required roof area for a solar roof system depends on multiple factors, including the following main factors:

Energy demand: How much electricity consumption your rooftop system needs to support is a key factor in determining the required area. Usually, people determine the size of solar energy systems based on their household electricity needs. If you have a high energy demand, you may need a larger roof area to install more solar panels.

Solar panel efficiency: The efficiency of different types of solar panels varies. High efficiency solar panels can generate more energy on a relatively small area. If you choose low efficiency solar panels, you may need a larger roof area to achieve the required energy generation.

Area limitation: The actual usable area of your roof is also one of the factors determining the size of the solar system. If your roof area is small, you may need to choose more efficient solar panels to maximize the use of available space.

Geographic location: The efficiency of solar energy systems will also be affected by the sunlight conditions in your location. If there is less sunlight in your area, you may need a larger roof area to compensate for the lack of energy generation.

Overall, taking a household as an example, a typical solar roof system may require an area of tens to hundreds of square meters. However, the specific area requirement still needs to be calculated and evaluated based on the above factors, and combined with the actual situation for decision-making.