What a $100M Home Actually Costs to Own (Beyond the Price Tag)

A $100 million home doesn't stop costing money the day you buy it. That's when the real bill starts.

Owning a trophy estate at this level runs into the millions of dollars every single year — before you've slept a night in it. Property taxes alone can clear seven figures. Then come the staff, the insurance, the security, and the upkeep on a property that behaves less like a house and more like a small private hotel. Here's what it actually costs to keep a $100M home, broken down line by line.

Property taxes: the biggest recurring check

Property tax is the largest fixed cost most trophy owners face, and it never goes away. Rates vary by location, but the luxury tier typically lands somewhere between 1% and 2% of assessed value per year.

On a $100 million home, that's $1 million to $2 million annually — every year, indefinitely, whether you're in residence or not. A buyer in a low-tax state like Florida or Texas sits at the bottom of that range; a buyer in parts of New York, New Jersey, or coastal California can push toward the top. There's a wrinkle the ultra-wealthy exploit here: assessed value often runs below market value, and owners at this level routinely appeal assessments and layer on every available exemption. But even a favorable assessment on a nine-figure home leaves a tax bill larger than most people's homes.

The ultimate flex? At this tier, the annual property tax on one house exceeds the full purchase price of a very nice home almost anywhere else in the country.

Staffing: running a house like a business

A $100 million estate cannot be maintained by a cleaning service that swings by on Tuesdays. It needs people, often a lot of them, often full-time.

Industry staffing data puts annual household payroll at the $100M+ wealth tier at roughly half a percent of net worth, which translates to a full-time team and an estate manager to run it. A property of this scale typically carries some mix of rotating housekeepers, a house manager or estate manager, groundskeepers, a chef, and drivers — scaling up fast when the principal is in residence or entertaining. Elite estate managers alone command $180,000 to $250,000 a year, and that's one salary on a much longer payroll. Add payroll taxes, workers' comp, and a household-employment accountant on top of every wage, and the staffing line for a true trophy estate runs comfortably into the high six figures and often past it.

The point isn't the headcount. It's that a house this size is a 24/7 operation, and operations cost money whether or not anyone's home.

Insurance: hard to get, expensive to keep

Insuring a $100 million home is its own challenge, and in 2026, it's getting harder, not easier.

Standard carriers won't touch properties at this level; trophy estates need specialty high-net-worth insurers covering the structure, the contents, liability, and increasingly, climate risk. Premiums for ultra-luxury properties run into the tens of thousands annually at minimum, and climb sharply for anything in a wildfire, hurricane, or flood zone. Homeowners insurance premiums nationally have surged nearly 50% over the past five years, and that pressure hits the high end hardest. Coastal and fire-exposed trophy markets are exactly where coverage is most expensive and most difficult to find. A Beverly Park estate, a Miami waterfront compound, or an Aspen mountain property each carries a premium that reflects not just the home's value but the cost of rebuilding it to its original specification.

Security: discretion isn't cheap

At nine figures, the home itself is a target — and so is whoever lives in it.

Security infrastructure starts with the hardware: advanced alarm systems, surveillance, and smart-home integration that can run well into five figures just to install. The bigger number is people. Full-time security coverage runs $50,000 to $100,000 a year at the lower end of the estimates, and a trophy estate with a public-figure owner often needs more than one detail, around the clock. Factor in monitored systems, secure access control, and the premium on genuine discretion, and security becomes a standing annual cost that rivals a senior staff salary.

Maintenance and utilities: the 1% rule, scaled up

The industry rule of thumb for luxury upkeep is 1% to 3% of purchase price per year, covering repairs, systems, landscaping, pools, and the constant work of keeping a large property pristine.

Applied to a $100 million home, even the low end of that rule implies roughly $1 million a year in maintenance alone. It's worth being honest about that figure. It's the standard percentage rule extended to the trophy tier, not a number measured on a specific nine-figure estate, and the true cost swings with the property's age, materials, and climate. A modern build in a mild climate sits lower; a historic estate, a waterfront compound battling salt and humidity, or a mountain property fighting snow load sits higher. Utilities scale with square footage and amenities — heating, cooling, and water for a 20,000-plus-square-foot home with pools and grounds is a serious monthly line on its own.

Can you write any of it off?

This is the question that separates a trophy home from an investment property, and the answer is mostly no.

A $100 million primary residence is a personal asset, not a business, so the big carrying costs — staff, insurance, security, maintenance, utilities — generally aren't tax-deductible the way they would be on a commercial building or a rental. Property taxes are technically deductible, but federal law caps the state-and-local-tax deduction at a level that's almost meaningless against a seven-figure tax bill. Mortgage interest is rarely a factor at all, because most buyers at this tier pay cash.

The picture changes when the home isn't purely personal. Owners who hold the property through an entity, rent it out part of the year, or use a portion for a legitimate business may unlock deductions or depreciation, which is one quiet reason so many trophy estates are owned through LLCs and trusts rather than in an individual's name. But those structures are driven as much by privacy and estate planning as by tax, and the rules are genuinely complicated. Anyone operating at this level is making these calls with a dedicated tax advisor, not a rule of thumb, and so should you.

The takeaway: at the trophy tier, the carrying cost is mostly a true cost, not a deductible one. You don't write it off. You absorb it.

So what's the real number?

Stack it up and a $100 million home costs somewhere in the range of $3 million to $6 million a year to own, before a single discretionary dollar on renovations, art, or lifestyle.

These are directional ranges, not a quote on any specific property — every line moves with location, size, and the owner's lifestyle. But the headline holds: at the trophy tier, the carrying cost of a home can rival the entire net worth of a comfortably wealthy family, paid out fresh every year.

Which is why, for most buyers at this level, the purchase price is almost beside the point. A $100 million home isn't a thing you buy. It's a thing you fund, indefinitely.

And for everyone who'd rather experience a property like this without the seven-figure annual bill, here's how to book a mansion for a week instead.