Modular construction and cross-laminated timber, together at last!

© Weber Thompson

© Weber Thompson Cross-laminated timber is a wonderful way of using up all those billions of board-feet of pine-beetle kill lumber that's rotting away. Cut it, glue it and press it, and you have giant panels that can used for strong, earthquake resistant and yes, fire resistant construction. It already is a form of flat-pack prefabrication, but Seattle architects Weber Thompson take it one step further: They are proposing to go modular with it as well.

Until now, modular construction and CLT have been studied and executed in isolation, but never in this combination,” says [Associate Myer] Harrell, who has a passion for sustainable design and won the AIA Seattle Young Architect award in 2011. “In order to really gain momentum, we’ll need to formalize a code alternate or code revision with the City of Seattle, and then work with an eager developer and contractor who are willing to go outside the boundaries of conventional building,” says Harrell.

© Weber Thompson

They explain why CLT is such an attractive material.

It is the sustainability and aesthetic aspects that appeal most to architects. When forested or recycled responsibly, wood has long been understood as a renewable resource with a net carbon reduction to the environment as analyzed in its overall lifecycle, things that neither steel nor concrete can claim. The ability to build more densely out of wood is a win-win for the green building movement. And, when detailed to expose the wood in walls and ceilings, CLT can help bring the warmth and beauty of wood finishes to high rises, achieving an honesty of structure to which architects often strive.

© Weber Thompson

The case for going modular with CLT is not entirely convincing. CLT is already cut in a factory to the exact prefabricated panel size, usually up near the forests where the wood comes from and is shipped very efficiently as a flatpack. One would have to set up another factory closer to the site to assemble the modules, which are too expensive to ship long distances. CLT high-rises in the UK and Australia went up really fast, and had all the chases for electricity and holes for plumbing pre-drilled, so that the trades could do the on-site work more quickly and easily. Going modular also uses more material, as every unit has its own walls and ceilings; in traditional modular there is a 30% increase in the amount of wood.

Flatpack CLT prefab is a pretty impressive thing all on its own. The wonder of CLT construction is that it is already fast, it is terrific for lower buildings which are often on tighter lots (and where it is harder to swing a crane with a whole module than just a panel). I wonder if modularizing it isn't a technological step too far.

More at Weber Thompson, whose own offices are, I think, one of the most important and overlooked buildings in America.

Alter Lloyd (2014 February 11) Modular construction and cross-laminated timber, together at last! Retrieved on February 14, 2014 From Treehugger.com

Why Architects Should Choose Modular for their Next Project

Architects might consider the benefits of modular construction for their next project. There are multiple reasons for why this would be a good choice. The great thing about modular construction is that is provides the architect with more flexibility and limitless design opportunities.

Factory built homes or modular homes are built piece by piece in a factory. The customer would work with a modular building company and or architect to design the building to their needs. A customer can choose from a pre-designed floorplans or custom design a layout to meet their specific needs. Modular buildings offer a variety of interior and exterior features to choose from, allowing the customer and architect greater flexibility while remaining within their budget and timeframe.

With modular construction, a great deal of construction takes place in the factory. This creates fewer site disturbances and less material waste. When building in a factory, entire buildings or major components can be reused and there is greater control of inventory, preventing waste and promoting quality construction.

Indoor construction means that workers will not be delayed by poor weather conditions; at least for the parts of the construction that is done indoors. Construction is never delayed from rain or freezing temperatures. Architects who intend to meet a deadline will be confident in their ability to do so with modular construction.

Lastly, architects and customers alike will enjoy the benefits of a green and more environmentally friendly construction method. Modular construction results in less pollution and waste. Buildings can be easily relocated or refurbished for new use, eliminating the need for new construction and reducing the demand for raw materials. Buildings can also be designed with energy efficient features such as daylighting, controllable systems and recycled material.