One of the somewhat unique things about Westchester County, especially south Westchester, is that it was almost completely developed after the 2nd World War. What this means is that there are very few newer homes, and the inventory that we have is older, often much older, than a typical home in other communities around the USA. The home I am living in now was built in 1962. A home I spent a chunk of my childhood in was built in 1890. We have terms here like "pre war" and "turn of the (20th) century" that describe some neighborhoods.
This means that things wear out. Roofs need to be replaced, Plumbing needs to be upgraded, Electricity needs to be modernized, windows have to be replaced, and on it goes. Older homes, like older bodies, require more maintenance.
The other side of matters is that Westchester is one of the highest cost places to live you can find. My own property taxes are over $16,000. The median price of a home is $635,000.
When you mix "old" and "expensive" and a you aren't talking about wine, then the purchase of the real estate requires due diligence. You have to do your homework, and you have to get a home inspection. A decent home inspection can be done for as little as $400. But the value of the $400 investment is priceless. It is more than a means of discovering possible defects and problems, it gives the purchaser peace of mind and serves as an instruction manual for home ownership.
You just do it. To skip an inspection, or to rely on your friend the contractor to walk through and size it up is the ultimate in being penny wise and pound foolish. It can help you avoid a far more expensive mistake, and has almost always saved money for the buyer in my experience. Unless you know going in it is a gut renovation and nothing will be left after the work, you get the home inspected. It is the largest purchase of your life. Have a professional check it out before you go forward.