This NYC Timber House Is a Template for Modern Sustainable Development

There are three subjects that I write about often on Treehugger: mass timber, Passivhaus, and bike activism. They all strangely converge at Timber House—located at 670 Union Street in Park Slope, Brooklyn—where Eric Liftin of MESH Architectures designed and built an almost-Passivhaus mass timber condominium project.

The bike activism aspect comes from Aaron Naparstek, the founder of Streetsblog and one of the trio responsible for my favorite podcast, "The War on Cars." He lives down the street from 670 Union and knew the family that owned two homes on the site. After the patriarch of the family died, Naparstek helped the family clean up the financial mess they were in. He knew Liftin and The Brooklyn Home Company, and they eventually assembled four properties and co-developed the project.

MESH Architectures describes itself as "a hybrid architectural practice spanning the physical and virtual" that is "always exploring new materials and technologies." So it is not surprising that Liftin chose to build with mass timber.

The building is described on Dezeen as New York City's "largest mass timber building" but that ignores the many warehouses and factories built 150 years ago out of big wood columns and beams, with "mill decking," or lumber stood on end and nailed together. It is still used and is now called nail-laminated timber (NLT). There is nothing new about mass timber; there isn't even anything new about glueing little pieces of wood together to get bigger pieces of wood.

What's changed is the recognition of wood's sustainable features: Wood is a renewable resource that doesn't have the upfront carbon emissions you get when making concrete or steel. Also, as Liftin notes, "Wood is beautiful. Its inherent warmth and texture mean we don’t have to cover it up or finish it, resulting in less waste overall."

But nothing is ever easy in New York City. While codes have been changing to permit larger mass timber buildings out of modern materials like cross-laminated timber (CLT) in other cities, the Buildings Commissioner balked at the use of new-fangled CLT at the time of application, so Liftin used glue-laminated timber (GLT) because it has been around since 1901 and was already in the building codes.

GLT is more commonly known as glulam and is usually found in columns, beams, and arches, but can also be sliced into slabs. It's made of wood laminations (lams) bonded together with glue, and with the grain of all the laminations running parallel. It is a "one-way" slab that must be supported on beams. The big benefit of CLT is it is a "two-way" slab that can be supported on columns, and because it is made of wood layers laid up at 90 degrees to each other, it is more dimensionally stable.

Liftin could have specified NLT but told Treehugger he didn't like the unfinished look of the NLT he had access to and preferred the smooth CLT-like finished look of the GLT from Vaagen Timbers. From the occupant's point of view, the only difference is you are looking at the edges of the lams rather than the side, and there is a 3/8" expansion gap between the slabs. They are topped with an isolation layer and lightweight concrete.

See our guide to all these different kinds of mass timber here, which starts with GLT.

The building also looks and smells like a Passivhaus design, with triple-glazed windows, an Intello+ smart air barrier all sealed up tight with Tescon Vana tapes, and Zehnder energy recovering ventilators for fresh air. However, it is not certified to the standard; Liftin is trained and certified as a Passivhaus designer but tells Treehugger he didn't think the people who were buying would care about it.

Also unusual for New York City, there is no gas line; heating and cooling is with heat pumps. Liftin explains, "We are looking to a near future when most of our electricity will be renewably generated. So we use electricity for everything, rather than burning fossil fuel (and needing to exhaust noxious gases)." He adds that "it used to be a hard sell to get people off gas, but not anymore."

There is secure parking for 33 bikes and the car parking spaces have charging stations. Liftin tells Treehugger "nobody drives around here" and he didn't want to provide as many car spaces as he did, but the development partners were nervous about not having them.

They stopped building out of wood in New York City over a century ago after catastrophic fires. When the first new mass timber building in New York was proposed by SHoP Architects in 2015 for a site in Chelsea, there was a lot of opposition from the fire officials who expressed "grave concerns" saying, “We’ve had a long history of problems with wood in New York, and that’s why we don’t allow it.” That project never got built, but anyone who has ever worked on a building knows the power of firefighters to walk in and demand changes—it has happened to me.

So when Naparstek started telling me about a squad of firefighters arriving on the site, I just imagined them saying something like, "Cover up all that exposed wood with drywall or no occupancy!" And there would be nothing you could do.

But Naparstek describes how Liftin was on site at the time and explained how mass timber has been tested and approved, gave them a tour, and then they left as if they had been on a field trip. So much has changed in just a few years.

There is so much for a treehugger to love about this building, from the mass timber construction, the near-Passivhaus specifications, the elimination of natural gas, and the parking for more than twice as many bikes as there are units. It's important to note there is not a vast underground concrete iceberg full of cars and that at six stories, it fits right into the neighborhood. This is a great template for urban development just about anywhere.

Watch the construction video and see how it is built from wood from the ground floor up.