To me it says that someone in the housing authority fell for a sales pitch on metal roofs. "Buy it once and never have to pay for a roof again." That person is now probably long gone, as is the salesman and likely the roofing contractor who installed it. The roof is now leaking, and the current administration looked at what they could afford and asphalt it is.
Metal roofs for SFHs are mostly beneficial in wildland / forest areas where there are wildfires. Shingles will burn (they're made of petroleum products), while a metal roof will resist far far far longer. However this only makes sense if the rest of the structure is also just as fire resistant.
Metal roofs will also last a lot longer. Their color may not, but the roof itself, as long as it was installed properly (major component here), will outlast asphalt by decades.
I agree. The sales pitch on metal roofs is that they last twice as long as shingles, but the reality has not matched that promise. If I were replacing a leaking metal roof that cost me twice what a shingle roof would have cost, and it has been less than 30 years, I would be a fool to buy another metal roof to replace it.
