For PV, if your roof shingles have 10 years or less of life in them, then we recommend having your roof replaced before installing solar. For Thermal, that number changes to 5 years or less. The reason for this is because removing and reinstalling solar collectors can be very expensive. While thermal systems only cost about $800-1,000 to R&R, PV systems can run in the $1,000’s. While you may lose some money on the remaining value of your shingles, you will more than make up for it in the energy savings that the solar system will provide!