30 percent roof rule 2

https://wiki-quicky.win/index.php/5_Signs_You_Need_a_New_Roof_Before_It%27s_Too_Late

The 30 percent roof rule is a common guideline in construction and remodeling, advising that no more than 30% of a roof's total area should be dedicated to features like skylights, solar panels, or vents to maintain structural integrity and weather resistance. Sticking to this keeps the roof strong and avoids leaks.