John Venator, now 70, didn’t mean to take on a costly, all-consuming project when he retired from his Chicago job as president of a technology association. Relaxing on a beach was more his style. But then he stumbled upon a home in Valladolid, Mexico.

It was a 17th-century hacienda that once housed the local mayor but had been abandoned since 1964. Attracted to its potential and a love of Mexican history, Venator put in an offer the same week. “It had good bones and had never been cut up,” Venator said.

It took more than eight years to fully restore the 18,000-square-foot (1,670-square-metre) home, says Venator who paid for it with US dollars and moved with his wife Dorianne just five years ago. The estate cost $150,000 and the couple ponied up another $450,000 for renovation.

Now the retirees enjoy a swimming pool with inlaid Italian tile, upgraded plumbing and appliances. What’s more, they charge for guided tours, and the income is used for upkeep or donated to local nonprofits. The monthly electricity bill is the single biggest expense at around $2,000, he says. Seven staff help with the constant upkeep, which includes 22 air conditioners, 147 ceiling fans, 18 bathrooms and five suites for the couple’s visitors. Owning a historic home, “you need to feel comfortable with some mess,” he said.

Venator isn’t the only one to fall in love with a piece of history. But looks can be deceiving. Behind all the ivy, original stained glass windows and historic brick, purchasing a home that’s more than 100 years old can mean spending more money than the price of the home on upkeep and lengthy renovations. Still, owning a historic gem that stands out from the new construction in your neighborhood is the draw, say homeowners. Here’s what to consider before buying a celebrated property:

How to find it

Some real-estate professionals specialise in finding homes which are officially designated as historic by local or national agencies. Consulting home registers can help you understand what’s sought after in a particular neighborhood and their official classification. Some sellers may tout vintage details that may not be valuable and simply used for marketing. But if a historic property is officially classified and created by a famous architect, be prepared to pay up. In 2014, the John B Storer home built in Los Angeles by architect Frank Lloyd Wright was listed for $6.9m by Crosby Doe Associates, a realty specialising in historic homes and estates. Nearby homes in the Hollywood Hills neighbourhood sell for less than $2m.

How to pay for it

Be prepared for red tape. Many countries restrict changes on homes with historic designations. In England, buildings on the National Heritage List must undergo a lengthy approval process to upgrade windows, facade or the inside. If the home is altered in a non-approved manner, the homeowner can be fined. Before purchasing his Mexico home, Venator had to agree to keep the original facade but was allowed to change the internal structure.

In many parts of the world it’s more common to get mortgage loans than financing for restorations. Banks can be unwilling to sign off on large loans because there’s no guarantee of the final product, says Peter Chinloy, professor of finance and real estate at American University in Washington DC. It’s difficult for “lenders to estimate what the property will look like completed,” he said.

But it’s not impossible to get money. In the US, borrowers can get federal loans to pay for renovations, but taking out secondary mortgages or additional credit lines is more difficult than it was prior to 2007. In France, renovation mortgages are standard and require estimates from contractors who are registered in France, so homeowners doing repairs frequently employ one main contractor to provide the relevant paperwork in order to secure a loan. Some countries, including the US and UK, offer tax credits or grants for those restoring homes with significant historical significance, Chinloy said.

How to recoup costs

When Lynn Carlton, 60, found a 1928 apartment in Buenos Aires’ Recoletta neighbourhood, she was thrilled that it had hardly been refurbished. Parts of the herringbone parquet floors were intact and the original door hardware was still in place. The apartment still had servant quarters so she worked with an architect to reconfigure some of the rooms and enlarge the kitchen to turn it into a more modern layout. Carlton visited area flea markets to find vintage sconces to fit the apartment’s vintage French theme, and an antique brass bed. She was so dedicated to a genuine restoration that she lived in a nearby apartment for a year while she oversaw the work. The 1920s “was an elegant time in Buenos Aires,” said Carlton who purchased the home in 2011. “I had to honor that.”

Carlton paid 1.3m pesos ($159,500) for the two-bedroom condo and spent another 500,000 pesos ($61,350) on restoration. The apartment cost 15% more than similar-sized apartments because it was a rare find, she said. Carlton, who also owns rental units in Mexico, hopes to recoup the cost of the renovation after two more years of rental income. The vintage details have also made it easier to rent. “Vacationers tend to have romantic concepts of the ‘Paris of Latin America’ and want to manifest that,” she said.

Higher renovation costs can often be offset by the lower purchase price of the home, said Sarah Winchester, 37, a photographer near Boston. Two years ago, she paid $200,000 less than some of her neighbours who bought newer homes. Winchester’s family of four moved into their historic home after upgrading electrics, putting in new air conditioning and kitchen “We didn’t want to invest too much, because you never want to be the nicest house on the block,” said Winchester who paid $73,000 to renovate the four-bedroom home.

Ongoing costs

Many homeowners don’t budget for existing renovations to historic properties and aren’t prepared for the time investment, Chinloy warned. Older homes “require more care after the renovation because the structural conditions remain,” he said, adding that it’s important to set aside money for repairs each month. Common problems include: water leaks, lead paint, fireplace maintenance, roof upkeep and poor insulation. Adding to costs, repairs on registered homes may need changes made in an original manner, be it restoring a garden wall hand-laid brick by brick or restoring an original roof.

The upside

For those that do enter the adventure, there is great reward. The Venators now offer daily tours of their home in Mexico for a fee. They get great pleasure showing off show off the estate and the couple’s extensive folk-art collection and proceeds help fund a local school, he said. The couple also hosts dinners for local government officials or international diplomats, including the French ambassador who recently visited the Yucatan region. Since making the purchase, “our life has been kind a surprise,” he said.

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