April 22 marks the 52nd anniversary of Earth Day. This year’s theme, “Invest In Our Planet,” is the altogether fitting theme as we emerge from the pandemic. Over the last two years, our homes, great and small, became our refuge, our solitude—and our solace. Of course, luxury homes are more than well-appointed safe spaces: Designers and builders have taken the cutting edge of new, “eco-friendly” technologies to create and renovate houses that embrace green architecture and green design and help us to build a sustainable future. They are building homes with locally sourced materials and are powered by sunlight, wind, and geothermal energy. There is an array of technologies that help offset our carbon footprint, such as humidity-controlled indoor air, filtered drinking water, LED lighting, HEPA air filters, and “smart home” internet systems and controls. Herewith, we spotlight 10 of the latest eco-friendly features and a sampling of innovatively built homes that offer the ultimate in luxury and sustainable living.

1. Sustainable and Locally Sourced Materials

This eco-friendly practice is actually not at all new: Before international shipping became commonplace, “locally sourced” was simply the method all builders used. They chose from stone, wood, thatch, or local clay, depending on which resources were abundant in a particular region. To reduce the carbon footprint of today’s construction practices, architects and contractors are seeking local solutions to new design challenges.

This environmentally sustainable home was designed in harmony with its mountain setting in Asheville, North Carolina. Canadian red cedar shingles, local timber, regional stone, and other natural materials echo the wooded environs. This recognition of the natural environment shows in the green technologies that have been applied throughout the home, including solar panels augmenting radiant floor slabs and the hot-water system.

2. LED Lighting

Electricity drastically transformed the nighttime look and feeling of interiors, replacing the soft flicker and glow of candlelight, of gas and oil lamps, with the hard, bright on-demand illumination of incandescent bulbs. Lighting is undergoing a radical change once again, thanks to advances in LED technology. LED bulbs are vastly more energy efficient than the filament bulbs of the 20th century, which means the carbon footprint of a home can be greatly reduced without switching off the lights. The Dutch multinational corporation Philips, founded in 1891 and a global leader in LED lighting, even produces LED-powered luminous textiles called Kvadrat Soft Cells that can add an atmospheric glow to any interior without the need for a single fixture. And, of course, software, smart phones and their virtual thumbwheels can instantly change the intensity, temperature, color and even the very moods of light—restoring the soft, romantic flicker and glow of ancient lamps and candles.

Penthouse 42C at The Ritz-Carlton Residences, New York, NoMad, is the perfect New York City pied-à-terre. Rising nearly 500 feet above Manhattan’s iconic skyline, the one-bedroom, one-and-a-half-bathroom, 989-square-foot penthouse suite offers unparalleled panoramic views of One World Trade Center, the Statue of Liberty and well beyond. Among the many custom features are white oak floors and millwork, Bardiglio Nuvolato marble finishes and bronzed glass cabinetry with integrated LED lighting.

3. LEED Certification

LEED certification has become a byword for eco-friendly construction practices. LEED (Leadership in Energy and Environmental Design) is a green building certification program from the U.S. Green Building Council that recognizes a project’s efficiency standards. It is the most widely used green building rating system. According to the council, more than 430,000 homes around the world are LEED-certified. The United States has the most LEED-certified homes. California, Texas, New York, New Jersey and Georgia are the states with the highest number. Green single-family homes represent approximately 40 percent of the market, and 84 percent of all residential construction will have sustainable features.

This one-bedroom, one-and-a-half bathroom turnkey home is at The Residences at Seafire, a LEED-certified luxury building on Grand Cayman’s famed Seven Mile Beach. The light-filled living spaces include a private terrace, gourmet kitchen with Miele and Sub-Zero appliances and furniture by Restoration Hardware. Owners at The Residences at Seafire enjoy access to unparalleled amenities at both The Residences at Seafire and the adjacent resort, the AAA Five-Diamond award-winning Kimpton Seafire Resort + Spa.

4. New Habitats for Sea Life

One of the most exciting trends in eco-friendly building isn’t happening on land, but on the ocean, where innovative new projects such as eco-friendly artificial islands are creating stable habitats for human beings and for the sea life below. Coral, fish, anemones and all manner of microscopic creatures can carve out a home using the base of each island, as though it were a natural rock formation. Smart ecological designs are applied on both land and sea, reducing the impact on marine life and even creating an underwater sanctuary for native species and “climate migrants,” aquatic animals on the move due to lost habitats.

The 122-acre landholding on Butedale Bay in the Great Bear Rainforest of British Columbia, Canada, is a coastal development opportunity like no other. The property includes 30 acres of deeded land, 28 acres of deep tidewater bay, 64 acres of long-term leased land and rights of way, hydro-electric licenses, and freshwater and approved marine operation rights. Butedale Lake is a natural source of freshwater that flows through Butedale’s freehold lands and cascades down a waterfall into the deep tidewater bay below. This merging of freshwater with seawater creates a diverse ecosystem that attracts a variety of marine life.

5. Vegetable Gardens and Orchards

Tending a garden is a proven way to clear the mind and enjoy some fresh air and sunshine. And there’s an added benefit: You can eat your work. Vegetable gardens are as good for the planet as they are for the gardener and the dining room table. With increasing interest in organic produce, home vegetable gardens have become a feature of luxury estates, where a scaled-down version of the “farm-to-table” concept goes right into the kitchen. Gardening promotes the cycle of growth and decomposition that maintains healthy soil, and growing plants produce oxygen—as well as the ingredients for a farm-fresh salad. With enough space, an avid gardener can tend a grove of citrus or apple trees or even produce wine from a small vineyard. Like vegetable gardens, orchards surround a home with fresh air and greenery, offer natural shade and perfume the air with the subtle fragrances of fruit and flowers.

Windward Farm in Hunterdon County, New Jersey, is a 125-acre sanctuary within commuting distance of both New York City and Philadelphia. The property includes a working farm with fruit, vegetable and herb gardens; a fig orchard; cultivated fields; an apiary; chicken coop; several barns; and two vineyards with an event space. There’s also a magnificent main residence with lavish indoor and outdoor entertaining spaces, squash and tennis courts, a sauna, gym, yoga room and a heated saltwater pool.

6. Green Roofs and Walls

Green roofs are aesthetically pleasing and environmentally friendly. Using vegetation in place of conventional roofing materials also reduces air pollution and absorbs stormwater runoff. They also lower energy costs and even extend the life of the roof’s supporting structure. The earliest “green roof” might have been the famous Hanging Gardens of Babylon, but it was not until the early 1970s in Germany that technology caught up with aesthetics and green roofs became a viable design option. Today, green roofs are so practical and effective that mainstream, design-focused authorities like HGTV are offering primers on how to install your own. Luxury homes have incorporated green roofs and balconies for a mix of efficient, natural cooling and landscaped, aesthetic beauty.

Villa sa Contissa is a sleek, eco-friendly retreat in Porto Cervo, Sardinia. The home is built into a cliffside above the sea; its stone walls are evocative of the granite boulders surrounding the home; its green roof blends into the enveloping Mediterranean shrubland. The fluid, light-filled interiors, which include nine bedrooms and 10 bathrooms, reception rooms, a theater, gym and spa, open to a dazzling, 130-foot-long swimming pool. Beyond are lounging areas and lush gardens overlooking the Emerald Coast.

7. Solar Panels

Using the inexhaustible energy of the sun, solar rooftop panels can provide a lightweight, long-term, cost-effective way to boost the passive energy of a home. Solar panels are on-trend and can be an attractive and artistic addition, whether the home is brand new or centuries old. Sweden’s SolTech Energy produces beautiful glass roof tiles that allow builders to create energy-efficient, solar-powered homes that draw design inspiration from a classic architectural style.

This home on Maho Bay is an oasis on the North Shore of St. John in the US Virgin Islands. The four-bedroom main residence and private one-bedroom apartment are built with rugged post-and-beam construction to withstand adverse weather, while a solar-paneled roof and generator ensure the property is self-sufficient. Central air-conditioning, a fully equipped chef’s kitchen, carport, one-car garage, indoor boat storage and a heated outdoor pool are further amenities. The lush gardens are planted with banana, mango, lime and coconut trees. An exclusive, deeded-access white-sand beach is just a short walk away.

8. Smart Home Technology

Today’s eco-friendly houses aren’t just sustainable, they’re smart. AMX, part of Samsung’s Harman Professional Division, de​​signs ​and engineers the Internet of Things. Crestron is another company on the forefront of home automation. Both AMX and Crestron smart-home systems control light, heat, ventilation, sound and even irrigation at the touch of a button. Ideal for homeowners who split their time among several residences, each home-automation system can be programmed remotely so that energy is not wasted when the property is vacant. Smart technology can also help protect the home. There are many apps with remote, one-touch security notifications, such as surveillance cameras alerts, presence detectors and live-stream audio-visual transmission.

This grand French-inspired manor is enveloped by woodland atop a hill in an exclusive enclave of Alpine, New Jersey, just eight miles from New York City. Completed in 2017, the 25,700-square-foot chateau-style manor was constructed over four years in a collaboration of artisans led by architect Robert Zampolin, builder Ron Badalamenti, interior design by Interiors by Denise. This property is fitted with the latest in smart home automation, including a one-touch remote-controlled Crestron system that coordinates all lighting, sound, heating and cooling, security cameras, shades and the pool and spa.

9. Geothermal Heating and Cooling

Like solar panels, geothermal heating and cooling harness the forces of nature to provide optimal indoor conditions at any time of year. This technology lets homeowners minimize the most luxurious home’s environmental footprint, even as its design makes a big aesthetic impact. An efficient geothermal system can provide 20 years of reliable heating and cooling with minimal maintenance, so the benefits of installing one may outweigh the costs, especially if it’s for a new-build or to replace an old system.

The River House Estate is a nature lover’s paradise on 293 forested acres in the northern British Columbia wilderness. The main residence, the River House, is a beautiful, custom-built log home equipped with geothermal heating and cooling. There are also river and lake cabins, an angler’s inn, a workshop, outbuildings and garages, a helipad, hiking trails, a 15-acre private lake and a mile of frontage on the Bulkley River.

10. Private Eco Preserves

And, finally, there is the eco preserve, where the owner is not so much landlord as steward of the earth and water, living in serene harmony with nature. The concept of an eco-friendly lifestyle is evolving to include health and wellness. Add nature conservancy and outdoor recreation to the mix, and the solution may just be a home on a private preserve. Those in search of greener pastures will find the perfect balance: living mindfully within nature.

Hacienda Pucheguin is one such eco preserve. Encompassing 348,000 acres in North Chilean Patagonia, 68 miles from Puerto Montt (which is an hour and a half by plane from Santiago), this one-of-a-kind property is composed of breathtaking, pristine forests, rivers, lakes and granite peaks in a region of untouched wonder. The property provides boundless possibilities for hiking, hunting, camping, fishing—and conservation.

This article was originally published on Luxury Defined by Christie’s International Real Estate.