Structure

Getting Down to the Details

Live from behind a stack of full-scale detail drawings, it’s the Thermal Mass and Buoyancy Ventilation Research Project Team! Lately, the team has been investigating all details inside and out. Starting out with material pallet and ending up at chimney flashing, the team is kicking it into high gear.

Cladding Material

Unsurprisingly for a project so focused on the interior systems, it was difficult to make decisions regarding cladding. Initially, as seen in previous models shown above, the team experimented with separate cladding systems for the chimneys, Cooling Patio ceiling, and exterior walls. For iteration 1 of the test building design included a timber open-joint cladding system wrapping every surface. Next, for iteration 2, the cladding system wrapped only on the exterior wall faces of the buildings and the adjoining chimney faces. However, thin sheet metal covered the roof, cooling patio ceiling, and the chimney faces which touch those surfaces.

The consistent cladding of iteration 1 appealed better to the monolithic nature of the SIPs structure. It also reinforced the importance of the chimneys to the buildings as a whole from the exterior. From there the team began to test if the timber was the correct mono-material for the test buildings. Seen above are renderings testing different materials for the cladding, columns, retaining walls, and benches. It is important to view these materials as they interact in the Cooling Patio. While sheet metal and polycarbonate cladding options may look more monolithic, timber is a low carbon material that better represents the heart of the project. In some cases, timber as a building material acts as a carbon-sink meaning it stores and processes more carbon than it produces. This of course relates strongly to the passive goals of the Thermal Mass and Buoyancy Ventilation Research.

Recycled Retaining Wall

Now the team is settled on the timber cladding, but they are not convinced of the retaining wall and bench materials. These aspects want to be a more earthen material as they rise from the ground towards the test buildings. After investigating rammed earth and concrete, the team wanted to find something more stackable. Concrete and rammed earth are beautiful, but they require formwork which requires more time. Something stackable will give the team more flexibility as well as members are movable.

Thankfully, down here on Highway 61 road work is being done to remove a load of 8″ x 8″ x 8′ stackable concrete barriers. The TMBVRP team is getting their hands on some of these reusable members and are calling around to local highway departments to find more similar materials. If they find enough, they will have a durable, stackable, and reusable material for their Cooling Patio. They can also use the old sidewalk pieces as a mosaic, ground material for the Cooling Patio. Above are drawings showing the use of these recycled materials.

Structure and Detailing

For the past three weeks, the team has been meeting consistently with Structural engineer Joe Farrugia. He is guiding the team through lots of math to size their columns. While the gravity load on the columns is extremely manageable, the wind load is more difficult. The test buildings height means they will face more wind load than a structure this size typically experiences. However, Joe is confident that the structural system the team has chosen is doable with the correct column sizing.

While the team is attempting to draw every detail of the test buildings, they’ve found the trickiest spots to be around the chimneys. Making sure water moves off the roof consistently and air moves behind the ventilated screen is crucial. The TMBVRP will spare you the pain of walking through each flashing bend and board cut. Struggles emerge when the chimneys converge with the angled roof, but it’s very doable with lots of thinking, drawing, and redrawing. Then Andrew Freear and Steve Long, come in to save the day because how you’ve redrawn it five times is still wrong. Lots of covered wall reviews later and the TMBVRP team is on their way to compiling all the details in a digital model and drawing set.

Looking forward to keeping this momentum going, the TMBVRP can be found in Red Barn from dawn to dusk. Feel free to bring by some late-night snacks but for now thanks for TUNING in!

How do we build that?

Now that the pods have been given forms, it’s important to figure out how we can make them stand up. To accomplish this, we are comparing three different structural systems to find the best method. We are considering Cross Laminated Timber (CLT), Structural Insulated Panels (SIPs), and more conventional stick framing systems.

All of these systems require slightly different assemblies, and we drew many wall sections to begin to understand them.

These forms also require unconventional joints at odd angles, so we did studies of how to join corners, whether with panelized systems such as CLT and SIPs, or stick framing.

By the end of these studies, and with the help of a review from Hank and Julie of KoningEizenberg Architecture, we began to realize that these forms were too complex, and could be simplified without forgetting our experimental requirements. This led us to a form we’re calling the “Rowhouse”. 

We will continue investigating structural systems using the Rowhouse form. We are currently investigating using the SIPs systems, as they offer a high insulating value while integrating structure. Our next steps will be designing the thermal mass panels that will live in these structures.