Pollution, allergens and Covid have homeowners focusing on filtration systems and flexible designs to improve indoor air quality
7 min
Visitors to John Bautista and Pedro Salrach’s San Francisco home can’t get enough of the lap pool, sauna and movie theatre. But they also get a whiff of something else they value: clean air.
“The house smells new—and after two years it still smells new,” said Bautista, an attorney. “I know when I’m home because it smells clean and fresh.”
The six-bedroom home with seven bathrooms and two half-baths includes an elaborate air-filtration system meant to deal with the region’s varying air quality. The tightly sealed floor-to-ceiling windows and sliding doors offer hilltop views of the bay and access to the backyard without sacrificing air quality.
Bautista plans to further upgrade his system this year with the aim of filtering and recirculating indoor air rather than fresh outside air during periods of heavy pollution. Despite the home’s superior air quality, the family can still feel a difference on days when the outdoor air is filled with smoke. “We’ve suffered, as most people have in the Bay Area,” he said. “What we want to have is isolation.”
Developer Gregory Malin, who specialises in wellness-focused real estate, sold Bautista the home for $32 million, he said, plus an additional $5 million for fixtures and furnishings.
Luxury homeowners are known to splurge on sleek kitchens, custom decor and art, but they are increasingly turning their attention to something less visible. Forest-fire smoke, the pandemic and increased awareness of sensitivities to mould and other irritants are making their interior environment a priority.
Many are investing in complex systems and flexible designs that promise healthier indoor air but still include spaces, such as glass-enclosed rooms, that make being indoors feel natural.
Listings are increasingly touting pollution-fighting amenities to lure home buyers. In Santa Rosa, Calif., a 13-acre estate for sale at $15 million has a whole-home air purifier. This spring, the Dovecote building, under construction in Manhattan’s Harlem neighbourhood, will offer six, three-bedroom condos built to strict green and clean-air standards, starting at $1.5 million.
Malin, founder of Troon Pacific, a San Francisco-based developer of $15 million to $45 million properties that he calls healthy homes, said he focuses on the smallest details that can affect air quality. New tools allow for more-precise measurement of various particulate matter and carbon dioxide levels, he added. “Covid changed people’s perspective on connecting air quality to health, and the [wildfires] only enhanced that.”
His company’s newer homes have exhaust fans, tied to ventilation systems, in laundry rooms and under sinks, where there are various pollutants and harmful cleaning products, said Malin. Their garages have separate exhaust fans that go on long enough for three air exchanges after the door opens. Ionisation-based filtration systems also are included to eliminate airborne particles too tiny to see but hazardous when inhaled.
His homes also feature perforated piping with in-line fans to exhaust air from under slab foundations to keep contaminated soil vapours from entering the houses.
He said his company is considering building to the Living Building Challenge standard, in which homes have their own electricity, water and waste management. Demand is high for such standards, he said, including passive-home construction, where airtight homes are built using specific materials and energy-efficient systems that circulate highly filtered air. He said passive-home certification is costly, especially for big homes, and has limitations that some homeowners don’t want, like bulky windows. In the long run, however, he said eliminating most heating and cooling bills is probably worth it.
Clean air has become more of a talking point in homeownership, added Elliott Gall, an associate professor of mechanical and materials engineering who researches indoor-air quality at Portland State University.
While high-rises are often built to be airtight, there is a greater focus now on having windows that open while adding better filtration systems, he said. Units with outdoor access sometimes give homeowners another way to control the humidity and indoor air-pollution levels inside the home, he added.
To improve the air quality in her new Charleston, S.C., home, Caroline Smythe, 67, imported a hemp block covered in a mixture of lime and sand for the construction, rather than standard brick. Living in a high-humidity area means moisture can cause mould, said Smythe, whose 2,400-square-foot Lowcountry home was completed in 2023 for about $1 million, including $250,000 for the land.
Incorporating the new material allows the moisture to get absorbed in the walls and keeps humidity steady in the home. “It has very much an earthy feel,” said Smythe of her thick, soundproof walls.
Inside, the home’s two bedrooms and two offices have additional air-filtration elements, including stand-alone air filters for each bedroom. Smythe, a psychiatrist, chose a bamboo kitchen countertop and mineral-based wall paint to prevent any chemical off-gassing. “It makes a huge difference,” she said.
Homeowners have long tried to improve air quality. In the early 1900s, homes that let in fresh air were critical to good health, but by the 1950s some owners were trying to tame outdoor air pollution by focusing on better insulation. More recently, the pandemic made access to outdoor air essential, and turned the focus again to indoor-outdoor living.
Today’s picture is mixed. Climate change has made outdoor air quality less reliable, with the added problems of prolonged forest fires.
Many people are realising their indoor air quality is often compromised by a combination of poor indoor airflow, activities like cooking and cleaning, and outdoor pollutants that settle into confined spaces, said Gall. Homeowners now want better control over their wider living space, including modifiable systems that deal with both indoor and outdoor pollution, he added.
Jason Glatt, a commercial window contractor, and his wife, Lauren Glatt, a stay-at-home mom, of North Bethesda, Md., built a $2.5 million home that includes a children’s slide into a basement playroom, an attic-level cigar room and plenty of entertaining space.
The 11,000-square-foot home’s most striking feature, however, may be the five HVAC units tucked inside utility closets and other closed rooms, controlled by eight thermostats that regulate the air quality as well as temperature in each part of the home. Their $120,000 HVAC system also includes UV lights to prevent mold.
Seth Ballard, an architect who worked with the Glatt family, said individually controlled temperature zones and more return-air vents promote better air flow. Costs can be $100,000 to $200,000 for a 10,000- to 15,000-square-foot house. “They are choosing this over a kitchen countertop,” he said of homeowners in general.
Charlotte of the Upper West Side, a building in Manhattan that opened in 2023, has seven full-floor units, each with a private entrance. The building has airtight construction with enhanced insulation. Each unit has an independent heating-and-cooling system with fresh-air filtration directly into the home that isn’t shared with other spaces.
The system can achieve full air exchange 13 times a day in normal-use mode and more than 28 times a day in boost mode, said the building’s developer John Roe of the New York-based Roe Corp. The building uses louvers outside the windows to deflect the heat of the sun and cut energy use on summer days.
Roe, who lives in one of the building’s 3,570-square-foot, four bedroom, 4.5-bathroom homes, said the air-filtration system and strict passive-home construction added 15% to the building cost.
Three of the building’s units are on sale, from $8.35 million to $17 million.
He said there is little dust in the home, and he swears it now takes longer for his cut white hydrangeas to wilt.
Copyright 2020, Dow Jones & Company, Inc. All Rights Reserved Worldwide. LEARN MORE
Rugged coastal drives and fireside drams define a slow, indulgent journey through Scotland’s far north.
A haven for hedge-fund titans and Hollywood grandees, Greenwich is one of the world’s most expensive residential enclaves, where eye-watering prices meet unapologetic grandeur.
Australia’s wealthy class is expanding fast, and Knight Frank says that a surge in billionaires is reshaping the nation’s luxury property market.
3 min
Australia’s luxury property market is being quietly reshaped by one of the most significant wealth expansions in the world.
According to Knight Frank’s latest Wealth Report, the country’s billionaire population is set to grow by 77 per cent over the next five years, rising from 48 to 85 individuals.
That surge sits within a broader wave of wealth creation. Ultra-high-net-worth individuals, those with more than US$30 million, are forecast to increase by nearly 60 per cent to over 26,000 Australians by 2031.
Globally, the pace is accelerating. The report reveals that 89 new ultra-wealthy individuals are created every day, a figure that underscores a structural shift in capital formation rather than a cyclical upswing.
For luxury property markets, this is not just a headline number. It is a demand driver.
Australia’s wealth story is increasingly underpinned by diversification across resources, finance, technology and services, creating a depth of private capital that is both mobile and strategic.
And mobility is key. The ultra-wealthy are no longer tied to a single market. Instead, they are operating across multiple global hubs, maintaining footholds in cities like London, New York and Singapore, while using Australia as a stable base.
In this environment, real estate becomes less about shelter and more about positioning. Trophy assets remain desirable, but capital is increasingly being deployed across the full risk spectrum, from long-term holds to value-add opportunities. For Australia, the implications are clear. As wealth expands, so too does the expectation of product, and the locations that can attract it.
The billionaire effect
While property remains central to wealth preservation, the latest data shows that capital is increasingly spreading across luxury asset classes, albeit with a more disciplined approach.
Knight Frank’s Luxury Investment Index recorded a modest 0.4 per cent decline in 2025, signalling a stabilisation phase after several years of correction.
But beneath that headline number is a more telling shift. Collectors are moving away from speculative buying and toward assets defined by rarity, provenance and cultural significance.
Impressionist art led the market, rising 13.6 per cent, buoyed by landmark sales including a US$236 million Klimt painting. Watches also performed strongly, up 5.1 per cent, driven by continued demand for brands like Patek Philippe and Rolex.
At the same time, more volatile categories have corrected. Whisky values fell 10.9 per cent, while parts of the fine wine market have softened following pandemic-era highs.
Perhaps the most notable trend is behavioural. Younger investors are entering the market through fractional ownership platforms, gaining exposure to high-value assets that were once out of reach.
For property, the parallels are clear. The same focus on scarcity, narrative and long-term value is increasingly shaping buying decisions at the top end of the residential market.
Global wealth
The growth in billionaires is not just increasing demand, it is changing where that demand is directed.
In Australia, Brisbane has emerged as one of a handful of global cities experiencing rapid change in its luxury positioning. The city’s transformation is being driven by infrastructure investment and the 2032 Olympics, with top-end apartment prices rising from around US$6 million to more than US$10 million in just 12 months.
Luxury price growth has remained steady, with Brisbane rising 2.1 per cent in 2025, while the Gold Coast recorded 2.8 per cent.
At the same time, buying power is tightening. US$1 million now buys 5 per cent less in Brisbane than it did five years ago, reflecting the upward pressure on prime markets.
The trend is not confined to capital cities. Regional lifestyle markets are also capturing attention. Geelong’s waterfront has been identified as one of the world’s hottest luxury residential markets, driven by a combination of coastal amenity, infrastructure and relative value.
In these markets, pricing is no longer the sole driver. Lifestyle, accessibility and long-term growth are increasingly shaping buyer decisions, particularly among globally mobile wealth.
Alternative luxury assets
Beyond residential property, high-net-worth individuals are continuing to diversify into alternative assets that combine lifestyle and investment potential.
One of the most compelling examples is vineyard investment. Knight Frank’s Global Vineyard Index highlights the Barossa Valley as one of the best-value wine regions globally, where US$1 million can secure more than 18 hectares of land.
Despite a 10 per cent decline in land values over the past year, the broader outlook remains positive, particularly as the global wine industry shifts toward premiumisation.
This “trading up” trend is seeing consumers favour higher-quality, provenance-driven wines over mass-market products, reinforcing the long-term appeal of established regions like the Barossa and Eden Valleys.
For investors, the appeal lies in the intersection of lifestyle and capital preservation. Vineyard assets offer not only production potential, but also a narrative — something increasingly valued in a market where experience and authenticity carry weight.
