Welcome to Riverhead Building Supply

Home improvement professionals and homeowners look to us for a broad range of building supply products and specialty services. Providing the highest quality products and customer service is our main objective.

Find Marvin Windows and Doors at Riverhead Building Supply. Marvin is an industry leader in product innovation and energy efficiency, offering the most extensive window and door options. Experience Marvin's expert craftsmanship and superior materials for yourself. Visit one of our convenient locations on Long Island and speak with a design expert. Our consultative approach simplifies the selection process, enabling our customers to select the products and features needed to make each project as unique as they are.

The Ultimate Double Hung Window. A tradition that never goes out of style.

The Double Hung window from Marvin® has been a prominent feature in American architecture for centuries.The advanced engineering integrates a time-tested classic look with state of-the-art durability, versatility and ease of use. Smooth operation, tilt-in convenience and extensive size, shape, and finish options make this the perfect window for remodeling, replacement or new construction. Marvin lets you have it all. Timeless beauty paired with superb function.

Marvin Coastal

Living in a coastal area comes with the added benefit of enjoying some of the country’s most amazing views.  But it also comes with the added responsibility of taking extra care with the building materials you choose.  Exposure to the elements can take a toll over the years.  That’s why Coastal Complete from Marvin is the ideal solution.  Specifically designed to stand up to whatever Mother Nature dishes out, it delivers a long-lasting, worry-free promise, 365 days a year.   And Marvin also offers StormPlus® protection, for those facing the harshest conditions.

Marvin Contemporary

Sometimes the best thing a window can do is get out of the way and connect your room with the outdoors.  Modern home designs are all about maximum light and visibility, and no windows and doors complement this better than Marvin Contemporary.  Available in a variety of styles and shapes, this collection will allow you to turn every window and door into a work or art, framing spacious views that will take your breath away.   And, our endless customization options are not only beautiful, but energy efficient, meeting or exceeding ENERGY STAR® guidelines.