Extended buildings

Everybody tries to maximize the building placement and efficiency of production. However, even with the most optimal building placement sometimes you have half a space left where you cannot place a new building because it's too small, but it still feels like "lost" space.

My idea is that you can upgrade or extend a building, making the space used not 2x2, but 2x3 or 3x2. This should be very expensive and give +10-25% production per building, so it's not worth it to extend every building you have. Only the buildings that are next to a 1x2 or 2x1 free building space on a full island will get the incentive to use this extension.

Consider how many buildings there are and then the length of time to make a new graphic for every single one just to use that small space. The better idea is extend the island or give us a new island.