Clearly the most important factor when relying on solar power for energy is sunlight. With this in mind you should look for a property with a south-facing wall that has good access to sunlight. The reason for this is that you will be reliant on the low sun coming from the south in winter. It can be hard but you need to look for any potential blockages to your sun light in the future as well such as tress that are growing near buy. You also need to think about the materials used in the house as you not only need to create energy but also prevent heat leaving your home be sure that the house is made of good heat storing materials such as concrete.