If I wasn't so lazy, I'd look for the study for details but some obvious support for the study is looking at the lifespan of a roof, hot water heater, HVAC, and appliances.

Roof: 30 years

hot water heater: 10 years

HVAC: 15 years

Appliances: 7 - 12 years

Some items last much longer than average but your first 10 years of the houses life, pretty much nothing needs to be replaced. Replacement costs, for the most part, start during years 10 - 20 and again in years 20 to 30 when you also get to put on a new roof.

Like I originally said, the current market will cause one to adjust the study's age brackets for profitability.

I'm not sure what your point is with the rent vs buy and rent compared to carrying cost of properties with a mortgage. My comment was only about the cost to maintain a home and how that affects the profit when you sell it. Renting doesn't factor into the total cost of ownership for a house.