Justin Marinoff: Mercer Built’s Luxury Building On The East End & Beyond

Hamptons builder, Justin Marinoff. Photo: Ty Wenzel

Nestled in the idyllic landscapes of Long Island’s prestigious Hamptons and North Shore regions, Mercer Built has established itself as a premier builder of luxury homes known for exquisite craftsmanship and relentless pursuit of perfection. The future of building on the East End is full of excellent young builders who understand what it takes to make the building process more sustainable, interesting, and with amenities that the modern homeowner demands.

Led by master builder Justin Marinoff, Mercer Built creates bespoke dream homes tailored to the discerning tastes of high-end clientele seeking the ultimate in luxury living. In this exclusive interview, Marinoff provides an inside look at Mercer Built’s design philosophy, clientele, inspirations, and approach to building one-of-a-kind estates. Marinoff offers insight into the specialized world of luxury home construction through the lens of Mercer Built’s passion and expertise.

Justin Marinoff. Photo: Ty Wenzel
Hamptons builder, Justin Marinoff. Photo: Ty Wenzel

Tell us about your clientele.

Our clientele on the East End tends to be aged 35 to 60, generally from the city, and using the homes as their weekend or summer escape for their families, multi-generational family, or growing their family. Our clientele in northern Nassau County tend to be ages 30 to 45, with the goal of a special full-time home.

What inspires you right now?

Social media is a gift and a curse. The gift is that it has become really easy to find inspirational ideas to add to a space. Although we would never replicate someone else’s space, we will try to use what the client is attracted to, improve on it, and make it their own. The curse is, well, there are so many different, incredible things out there, and combining them can dilute the product, which is never good. With that said, less is more. Lately, we have been incorporating recessed, or flush millwork, hidden hinged doors with little to no detail, trimness recessed lighting. But truly, the most special “less is more” component we do is a custom process in some of our bathrooms or spaces where tile is typically used.

You’ve become one of the only Semco experts on the Island. What is it exactly?

A couple of years ago, we became factory-trained and certified to install a product called Semco. Have you ever seen a photo of a bathroom in Greece where it appears the bathtub and walls are all one? Same color, same finish, almost as if it was built out of plaster with no tile? With Semco, we can create that. We can create spaces that usually have tile and grout lines to appear as one continuous surface. Think of your garage floor, but highly refined, with hundreds of different colors and finishes. It can be used on walls, floors, sinks, countertops, and fireplaces — indoors and outdoors. The possibilities are almost endless. It truly takes the notion of less is more to another level. Over the last couple of years, wellness and fitness have become so important. We have expanded on that notion. The home gym is important, but we have been maxing out its potential. The lower-level bathrooms don’t just check the box of a sink, toilet, and shower — we have been putting saunas and cold plunges in them. Truly attempting to maximize the feeling of a vacation. I practice what I preach and cold plunge every day.

What makes building in luxury markets unique compared to other markets?

We build on the East End and northern Nassau County — two luxury markets. The gap in the differences between the homes used to be larger, but I feel like the gap has come closer together. Pickleball and sports courts, pool house cabanas, and multiple outdoor spaces with places to hang out (or hide, ha!) are incorporated into both.

How competitive is the high-end home construction space in the Hamptons? Do you do a lot of bidding or RFPs?

I believe it is highly competitive. Although cost is always a major factor, the compatibility of everyone involved is important. When an architect or client sends us plans, we realistically price the project.  When building a home, it’s a team effort. Not just the “building trade” team but the architect, designer, and most importantly, the client. The most successful projects, from the beginning, have transparency with budget, design, and roles from everyone. The build process does not happen overnight, and when there is good energy within the “team,” the end product shows.

Hamptons builder, Justin Marinoff. Photo: Ty Wenzel
Hamptons builder, Justin Marinoff. Photo: Ty Wenzel

How has rising inflation recently impacted the cost of materials and labor for luxury home projects? How are you managing costs?

Please make it stop.

What sustainability features are you integrating into luxury homes today, like solar panels, energy efficiency, etc?

Solar power. The benefits are great, but up until now, they aren’t incredibly pleasing to the eye. Although we always attempt to hide the panels. We are now installing a roof system where the actual roof is the solar power system. The standing seam metal roof doubles as the solar panels. This goes back to the previous “less is more.”

How much input do luxury buyers typically want when customizing their dream Mercer Built home? How do you meet their expectations?

Have you ever gone to a hotel, restaurant, spa, gym, or anywhere and thought to yourself, imagine this was your house? Residential homes have size, scale, and financial constraints/boundaries, but we want our clients to get that feeling. Whether it’s a home gym, bathroom, kitchen, or outdoor living, the space has the opportunity to create that feeling. It can be the smallest detail or something significant.

To learn more about Marinoff and Mercer Built, visit mercerbuilt.com or follow Mercer Built on Instagram.




Ty Wenzel

Co-Publisher & Contributor

Ty Wenzel, a recent breast cancer survivor, started her career as a fashion coordinator for Bloomingdale’s followed by fashion editor for Cosmopolitan Magazine. She was also a writer for countless publications, including having published a memoir (St. Martin's Press) and written features for The New York Times. She is an award-winning writer and designer who covers lifestyle, real estate, architecture and interiors for James Lane Post. She previously worked as a writer and marketing director for The Independent. She has won multiple PCLI and NYPA awards for journalism, social media and design, including best website design and best magazine for James Lane Post, which she co-founded in 2020. Wenzel is also a co-founder of the meditation app for kids, DreamyKid, and the Hamptons social media agency, TWM Hamptons Social Media.

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