The attic says a great deal about the condition of the roof before it is converted for photovoltaics. Stains, a smell of damp, unevenness and traces of repairs help establish the scope of work. It is worth inspecting them before ordering the covering, not only once it has been removed. A BIPV system can give the house a new function and a coherent appearance. It will bring the greatest benefit when the renovation also resolves earlier problems hidden beneath the roof slope. The areas around chimneys, roof windows and the junctions between the roof slope and the walls must be inspected. Water marks may indicate a leak, but are sometimes associated with condensation. The conditions in which they appear are important. Information on whether a stain grows after rain, during a thaw or on cold days helps the person assessing the roof identify a possible cause.

An attached garage can be a good place for an integrated photovoltaic roof covering. A new roof is easier to plan from the outset, and its appearance can be matched to the house right away. This does not mean, however, that every extension has the right pitch and solar exposure. It is worth comparing its potential with the main roof slope, checking for shading from a taller building and establishing how the system will be connected. Only then can a sensible active area be chosen. With a new garage, the geometry, the substrate and the cable route for the chosen system can be designed from the start. There is no need to adapt the active covering to a worn-out roof. Panels with cells and passive elements can form a coherent whole, and the electrical part can be incorporated into the shared construction schedule.