Welcome back to Period Dramas, a weekly column that alternates between raiding historic homes on the market and answering questions we’ve always had about older buildings.

Restoring a historic home is no easy feat. Not only do old structures and building materials need to be treated with extra care, but old houses are full of surprises, and costs can add up quickly. But if there’s one thing we’ve learned, a well-done renovation can turn a nightmare into a dream home.

We turned to one of our favorite interior designers and architects, fellow old-home obsessive Steven Gambrel, who has restored and renovated a number of 18th-and 19th-century homes in and around New York, such as the 1853-built Captain Overton House in Sag Harbor, to learn about what to expect and what to look for when restoring a historic home.

Living in an old house is an obligation. As a must-have, do you count on things like underfloor heating—or even just something like an evenly heated or cooled space? Then living in an older house, with its irregularities, might not be for you.

If you’re going to buy a historic home because you like the old wavy glass windows and the vibe of the floors, “understand that you won’t be able to have some of the comforts that are part of 21st-century life.”

“I would do anything to keep that undulating glass in the windows, even if that means having to have a draughty room,” adds Gambrel. I would just put on a different jersey. But if you’re not that person, then that’s not the right house for you. “

Water damage is the enemy

“Water damage is serious, important, and needs to be addressed,” says Gambrel. Water damage has long-term effects, such as dry rot. Insects also like wet environments. “

Keep an eye out—especially around ceilings, floors, and windows—for signs of water damage. That could be a warning sign of serious structural problems.

Something to pay special attention to is the sill plate. The sill plate is the lower horizontal part of the structure that wraps around the entire foundation. All vertical structural supports for the house are attached to the sill plate.

“The sill plate is most vulnerable to water because it is close to the wet ground,” Gambrel says. If the floors are skewed, it could be because of a warped sill plate because that’s the entire structure the house stands on.

Put together a team to assist you

A contractor and an inspector can help estimate the amount of work needed and its cost. But it can be helpful to research people with experience in historic preservation.

You need a local historian or contractor who restores historic homes. They can provide the most helpful and tell you about the recovery process that needs to be done, “says Gambrel.

And above all, anyone you take with you should understand your ultimate goal of restoring the property. “A lot of people don’t understand the difference between saving and …