Timber House at 670 Union Street

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TIMBER HOUSE AT 670 UNION STREET

by Eric Liftin, AIA, Owner & Principal, MESH Architectures

Section perspective We have been seeing a lot about mass timber around the world these days. It may seem counter-intuitive to some to “go back” to making buildings — often large ones — out of wood. But these are not your grandparent’s wooden buildings. They are sophisticated, beautiful, buildable, and make a ton of ecological sense. As an architect and some-time real estate developer, I set out to build a mass timber building here at home, in Brooklyn. Timber House is the first mass-timber condominium in New York City, and there are just a few other modern mass-timber buildings of any kind. The primary reason for their scarcity has been city agencies’ opposition. It was incredibly difficult to win DOB approval. That should change as the new building codes take effect this November. We are reminded that changing traditions and conventions is always difficult. But we must change in response to the climate crisis. The six-story, fourteen-unit building comprises glue-laminated timber columns, beams, and floorplates. (Technically it’s a hybrid structure: the core and lot-line walls are concrete block, per FDNY requirements.) Old-school heavy timber was hewn from old-growth hardwood trees. Today’s mass timber, by contrast, is fabricated from standard dimensional lumber, such as 2x8s, milled from fast-growing pine and fir trees. (You will hear mention of mass timber’s variants: CLT, GLT, DLT, and NLT. There are important differences between these, mainly in how the boards are fastened together, but they are all mass timber).

Top: Several floors constructed. Bottom: Drilling panel.

Mass timber is a sustainable and desirable alternative to steel or concrete for multiple reasons: 1. It is renewable. Responsibly harvested trees are quickly replenished. Some folks imagine a countryside denuded for its lumber, but the truth is that northern temperate forestry is running a surplus. We can handle a lot more construction lumber demand with sustainable practices. 2. It sequesters carbon. CO2 that the trees ingest becomes cellulose fiber, which becomes part of a building for many decades to come. The natural life of a forest is roughly carbon neutral, with young trees growing and old trees dying and decomposing. Harvesting and planting sequester carbon from the atmosphere. 3. Mass timber requires less energy to produce. The embodied energy in steel or concrete is intense, as both of these materials require high-energy metamorphoses. Mass timber does require processing and transportation, but this carbon footprint is much smaller. When a building reaches the end of its life, mass timber is easier to disassemble and dispose of responsibly than concrete, which is generally crushed for (inferior) aggregate. 4. Mass timber is much cleaner on site and generates less waste. The components show up on a flat-bed truck. They

are unloaded and installed immediately. It’s like assembling a giant piece of Ikea furniture. By contrast, setting up, executing, and cleaning up a concrete pour is a mess. 5. Mass timber is beautiful. Neuroscientific research has suggested that surrounding oneself with the nonrepeating, fractal patterns of natural materials engages the mind, both stimulating and calming it. We simply feel better in a room of natural wood than a white box. Of course it is always better to build with beautiful materials that inspire the building’s occupants. But beyond this obvious appeal, building beautiful structure saves material: ceilings, columns, and beams remain exposed structure, rather than getting clad in framing and drywall, for example.

What does the mass-timber construction site look like? Mostly like a cleaner steel building site, with carpenters instead of iron workers, or somewhat like a precast concrete building site. Another benefit is that the entire process of mass timber production can be domestic, from growing the trees to milling and forming the members to construction. So mass timber construction is also sustainable in terms of domestic employment and economy. The U.S. is behind Europe in building with mass timber, despite our wealth of forest land that can be responsibly cultivated and harvested. New York City has just this year legalized CLT, the most popular and advanced form of mass timber. The time to encourage building this way is now. When it comes to building, decisions made today will affect the surrounding environment for decades to come. Having been through the process, I can report that, absent the regulatory hurdles, it is just not that difficult. The pre-engineering required to mill the members in advance to fit properly and accommodate penetrations such as ducts is the trickiest part. And this is becoming easier as we become used to digitally modeling our buildings in accurate detail.

Exterior

Finished spaces. Photo Credit: Matthew Williams

In Timber House the sustainable attitude carries throughout the building. Passive-house-level performance is achieved with generous insulation, air sealing, triple-glazed windows, and energy-recovering ventilation. There is no combustion anywhere in the building. New York City recently passed a “gas ban” that we hope will hasten the sunset of burning fossil fuels in our buildings, despite that bill’s exceptions. Heating is by high-efficiency heat pumps, and cooking is via miraculous induction. Parking spaces in back feature electric charging stations. Solar panels generate electricity on the roof. All of these features are straightforward and affordable to implement today. It is critical to keep burning fossil fuels out of our buildings. Even if electricity today is mostly generated by gas (depending on where you live!), in the very near future electricity will be much more sustainably generated, which again argues that we act now to advance our approaches to construction because such choices will resonate for decades. l MESH Architectures (http://mesh.nyc) was founded in New York City by Eric Liftin in 1997 as an innovative architectural practice spanning the physical and virtual realms. MESH has designed a wide range of projects, large and small, residential and commercial. The firm believes in integrating the design of built spaces and digital experiences and has designed many websites, sometimes integrating them into architecture. Innovation and sustainability are integral to MESH’s design approach. Over the years MESH has experimented with new technologies such as translucent composites, LED lighting, and most recently, mass timber. In addition to a new mass timber building, the firm recently finished a rammed-earth school in Nepal. MESH embraces sustainable building, promoting passive-house construction. Liftin teaches environmental sustainability at Columbia University. For technological innovation, sustainable practices, and excellence in historic preservation, MESH has received awards from a range of organizations, including the Architectural League, the Cambridge Historical Society, the Brooklyn Chamber of Commerce, and Interiors Magazine.