Not too long ago, I happened upon an old Victorian house that had seen better days. It brought back vivid memories of the first old house I ever bought and renovated — a quaint, older three-bedroom home sold at auction for just $8,000 in the spring of 1975.

If I had known then what I know now, I might not have bought it. But the dream and adventure of buying and rehabilitating a “fixer upper” with historic charm is something many Americans pursue each year. If you’re considering going all-in on an old house, pay attention to the condition of the following elements, which may need partial or full replacement.

The foundation and frame. First and foremost, make sure the house has a solid foundation. Recently, my son was thinking of buying an old house and sent me a photo of a diagonal crack extending from the corner of a basement window down to the floor. The house was almost 100 years old. The crack was less than 1/16 inch wide, there was no evidence of water seepage and the concrete was not offset.

I pointed out that it’s normal for concrete to shrink as it cures, and cracks at window-opening corners are as common as flies at a summer picnic. The fact that there was no evidence of water seepage and that the concrete was still in the same plane suggested that there was no cause for alarm.

It’s also important that the house’s framing, or bones, is in great shape, with no cracks, wood rot or insect damage. The carpenters of yesteryear knew how to keep wood in great shape, and most used tar paper to keep the structure dry for decades.

Plumbing, specifically pipes. The presence of cast-iron plumbing stacks needn’t worry you, especially if you can see the cast letters “XH” on the pipe. These letters indicate that the pipe is extra heavy and can last for hundreds of years. (That is, as long as the previous homeowners didn’t routinely pour liquid drain cleaner down the pipes.)

If you see cast-iron plumbing in vertical pipes, it almost certainly means you’ll have smaller horizontal galvanized pipes that drain sinks, showers and possibly tubs. These pipes will almost always be in poor shape and require replacement.

Electrical wiring. The old electric wires and cables found in many early 20th century houses were not designed with enough capacity to handle modern appliances. You will likely need to install new cables to kitchens, bathrooms, laundry rooms and media or entertainment rooms where appliances consume lots of power.

Heating, ventilation and air conditioning. Don’t underestimate the cost to retrofit an older home’s HVAC system. Many older houses were built with supply and return air registers installed in incorrect locations by today’s standards.

Lead paint. If a house was built before 1967, you can assume it was coated with lead paint both inside and outside. You don’t have to get rid of it, but you do need to understand how to work with it so you and your loved ones don’t get lead poisoning. Never scrape or sand lead paint; even scraping exterior lead paint can potentially contaminate the soil.

Wood trim. If you’ve got the budget, you can buy custom wood trim to match both the interior and exterior details of an older home. Local lumberyards may have a mill, or they may know of a local mill, that can create matching profiles for all the fancy woodwork at your property.

Consider these issues at any older house that catches your eye. If listing information or visual clues indicate the presence of the problems or repair needs outlined above, hire a professional inspector affiliated with the American Society of Home Inspectors for further insights on the work’s scope and what is likely to cost.

Tim Carter has worked as a home improvement professional for more than 30 years. To submit a question or to learn more, visit AsktheBuilder.com.