CLT in the City: Using Cross-Laminated Timber for Infill Housing

My wife and I have provided rental housing in Eliot ever since we moved here 40 plus years ago.  Our intent then, as now, was to preserve Eliot’s older buildings threatened with demolition by developers who were, at best, clueless about the neighborhood’s origins and history.  One of these homes was at 19 NE Morris that was graced with a mature walnut tree that spread its branches across four adjacent properties.  We bought that property to protect the tree as the lot was zoned for multi-family units and was about to be sold to a developer.  After almost 30 years the house finally got to the point that it wasn’t economic to repair it and replacement required multiple units by code, so the house couldn’t be saved.  To save the tree, we were able to reduce the zoning code required number of new units from 6 to 4, which also allowed for a design like the adjacent townhomes (instead of the typical flat-roof modern box design).

I was Chair or a member of the Eliot Land Use Committee for multiple years.  A common complaint we heard from neighbors was that new development typically resulted in contractors blocking parking and sidewalks for months on end, which is a great inconvenience in Eliot.  I vowed to reduce neighbor conflict like this to a minimum by using construction methods that were faster than conventional “stick framing” that requires large numbers of workers.  This led to the selection of cross-laminated timber (CLT) panels that are quickly erected with a crane.  Eliot has a couple of multi-story CLT buildings so the technique isn’t new, but the use of CLTs for a smaller building was new, mostly because it is more expensive than conventional stick framing.  I thought the trade-off between construction speed and cost was worth it to avoid the prolonged inconvenience of neighbors.   

Erecting CLT walls – end of day one at 19 NE Morris. Photo courtesy Mike Warwick

The process for our project was simple in concept.  Provide a concrete slab foundation for the CLT panels, erect the panels using a crane, and finish construction using conventional contractors for electrical, plumbing, finish, etc.  The concrete was poured at the end of October.  The panels came from Austria, which has decades of experience with CLTs; consequently, they are better quality and less expensive than locally made ones, even with the shipping.  Plus, they meet the higher European standards for chemicals in the glue and the sustainability of the wood.  They arrived in November.  Erection was scheduled for mid- to late-December but waiting until after Christmas was favored by the construction crews.  Unfortunately, that was just about the last dry period we had for construction!

Three weeks from start of construction. Photo courtesy Mike Warwick

Part of the street was closed to public parking as was the sidewalk for two weeks starting January 21st.  The first panels were lifted into place by a very large mobile crane on the 22nd.  Panels continued to be installed for two more days and the crew got a couple of workdays to play catch up.  The crane returned the 28th and the final panel was placed at 4 PM the 29th.  Five days to erect the building shell and only two weeks of parking restrictions.  Unfortunately, the Park Department’s required “tree protection zone” around the lone street tree will keep the sidewalk closed for the duration of construction.  The roof trusses were installed in the first week of February, so the building shell was essentially complete in three, very rainy, weeks!  The shell was ready for siding and roofing the first week of March.  Finishing construction will take a while longer to coordinate among the different building trades.  The result will be four, new 2-bedroom townhomes in place of the original 2-bedroom home. 

Day five – final day of panel erection. Photo courtesy Mike Warwick

One thought on “CLT in the City: Using Cross-Laminated Timber for Infill Housing

  1. The paneling is pretty cool. But in the end, the only effort made to put some character into the house are some timber frame style beams used for the entry way. Besides that, unfortunately it just looks like a cheap box of a turd. It’s sad to see a new house in a decent old neighborhood with so little curb appeal or consideration for aesthetics……..and it’ll sit there for a hundred years. Yuck.

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