The panels are built up from narrow planks, about an inch thick, that are laid side by side to form layers. Like plywood, each succeeding layer — there can be as many as 11 — is laid perpendicular to the preceding one. The layers are glued and the entire sandwich is pressed and trimmed. Then, using computer-guided saws and drills, it is cut to the precise dimensions in the architectural plans, including window, door, plumbing and ventilation openings. Channels for electrical wiring can be cut into the panels.

At the construction site, the panels are hoisted into position and bolted together with metal brackets to build up the structure floor by floor. Construction can proceed fairly quickly — the Graphite Apartments were built in about two-thirds of the time it would have taken to construct a similar building in steel or concrete.

Prefabrication “offers tremendous savings in construction time and cost,” said Frank Lam, a professor of wood building design and construction at the University of British Columbia, where a CLT building that will house a bioenergy demonstration project is nearing completion. Its panels were made by one of three Canadian companies that produce them.

In the Graphite Apartments, even the interior walls are made of CLT panels. These and all the exterior panels are tied together, so the building load — the weight of all the materials, furniture, objects and people — is distributed through most or all of them. “Because the whole structure acts together,” Mr. Thistleton said, “you get this incredibly complex load path through the building.”

That complex path also helps protect against progressive collapse, when the loss of one structural element causes others to fail. It is relatively easy to design a CLT building so that if one element were destroyed — through explosion, perhaps — the load it was carrying would be safely carried by others.

Fire is also a major concern — and one reason, no doubt, that codes have limited the height of wooden structures — but solid CLT panels do not ignite as easily as small two-by-fours. “When you’re trying to light a fire in your house, you don’t start with a log,” Mr. Liddell said, by way of analogy. “You start with kindling. You could be hours getting that log to light.”

Even if panels do burn, charring on the outside protects the interior wood, leaving the panel structurally sound. Finishing the panels with wallboard or another material will improve fire protection. (Generally the panels are not meant to be left exposed, and at least one side must be finished anyway, to reduce sound transmission.)