Which city has greatest number of old and new houses?

Ninety-two per cent (92%) of the homes currently for sale in Detroit, and 83% of those in Baltimore, MD are at least 50 years old. Philadelphia, PA and Milwaukee, WI boast the third-highest shares of old listings: 76% each.
The Texas cities of El Paso, San Antonio, and Austin — as well as Oklahoma City — are the only large hubs where new homes built post-2012 make up more than 40% of the stock for sale.
New York City has the most homes for sale that were built in this past decade (about 4,500), followed by Houston and San Antonio with around 3,500 each.

Here’s something that will make you twist and shout: According to the US Census, nearly 40% of homes in the US were built before The Beatles broke up, according to the report. “Clearly, ‘out with the old’ is not something that defines residential listings in the country — particularly in staples like Detroit, Baltimore, or Philadelphia, the report found.

Detroit claims the highest percentage of older homes for sale: 92%. This means that around 2,400 of the 2,600 homes that are currently on the market in Detroit were built before 1970. Here, some of the oldest of the bunch — which were built as far back as the turn of the century — are mostly sold for land value, according to the report.

Baltimore also was found to have an abundance of vintage homes – one of the oldest dating to 1850 recently selling for $175,000, according to PropertyShark. Today, 83% of the current for-sale stock in Baltimore comprises homes completed at least 50 years ago — around 3,200 of all 3,900 current listings. By comparison, just 3% of Baltimore’s current listings were built in the last decade — the same percentage as in Detroit.

While New York City didn’t make the top half of the list, it actually has the largest number of pre-1970 homes on the market with a cool 16,500. In this regard, the Big Apple is followed by Chicago with 6,100 homes built more than 50 years ago, which represents 51% of its current for-sale stock.