This just in: there’s is a big hole in the Thermal Mass and Buoyancy Ventilation Research Project site!
Thanks to C & T Excavation Inc. the TMBV Test Buildings have broken ground. Local and Rural Studio excavation efficiando, Tyler, completed the initial site grading and the foundation dig. Let’s take a look at how the TMBV team prepped the site for this momentous day.
Newbern’s Newest Crater
Before you can dig a hole, you’ve got to know where to dig! This is where the superheroes of construction, batter boards, come into play. Batter boards are quintessential for starting construction so they must be precise. To clarify, batter boards are temporary frames, set beyond the corners of planned groundwork at common elevations.
Typically, batter boards consist of two stakes driven into the ground with a horizontal member held between them. Next, once you’ve assembled and leveled the batter boards, you use construction string to “pull” layout lines. The layout lines are then secured to the batter boards. Layout lines cross the site either east to west or north to south, between batter boards, to indicate the foundation limits at their intersections. It’s important to note the elevation of the top of each batter board must match so when strings are pulled across the strings intersect.
The TMBV team pulled their first layout line west to east from the Supershed columns. From this line, all other layout lines are set. When all lines’ distances and intersections’ squareness are triple-checked, the team marked the initial grading limits on the ground with spray paint. The end result, with string crisscrossing about like laser beams, feels a bit like a scene from an action movie. Especially if you practice jumping over and rolling under the strings. But, of course, none of these very professional research graduate students took part in such conduct.
At the end of a long day pulling strings, the team marked their initial grading and detached all the layout lines from one side. The layout lines positions are marked on the batter boards so they can be put up and down as needed. Obviously, you can’t build with a bunch of strings in your way. After the initial site grading, the students re-pulled the strings which indicated the foundation limits, marked the corners, and Tyler began digging again. In about 6 hours time, Morrisette Campus had a brand new swimming pool and the TMBV team had a real project site.
In parallel with site groundwork, the TMBV team worked across campus on their mock-up. To mimic the SIPs walls of the test buildings, the mock-up uses 2″ x 12″ stud walls. Due to the angle of the roof and the chimneys, there was much mitering to complete and even more mitering math to figure out. The team built all the stud walls and are ready to assemble. All the especially funky parallelograms you see below are the chimney pieces. With the kit of parts complete, the team awaits columns to build upon.
Cooling Patio Design
True to the design-build spirit, the team is still designing as they’ve started building. The ground plane of the cooling patio was the subject of this week’s design charrette. The team has used, concrete side-walk pieces they intend on using as pavers. However, it is not decided yet how those pavers are arranged.
The team wants to eliminate any excessive cutting of the pavers, especially exact cutting, so they ruled out a linear pattern. They are pursuing a mosaic-like pattern that minimizes concrete cuts. However, without a full inventory of all the concrete pieces, it’s difficult to produce a realistic design. Therefore, in the coming weeks, the team will be taking stock of their recyclable materials. After this, they can start laying out patterns using a steer skid loader to move concrete pieces around.
Welcome to Winter
As mentioned in the Thermal Mass and Buoyancy Ventilation Research Project Team’s last blog post, the chill has rolled into Hale County. There is never a shortage of beautiful scenery in these parts as proven by these frosty silos. By next post the TMBV team hopes to have another gorgeous view for you; a freshly poured foundation! Here’s hoping and thanks for tuning in!
The Breathing Wall Mass Timber Research Project Team, alongside collaborators and colleagues Sal Craig, Kiel Moe, David Kennedy and Rural Studio’s own Andrew Freear, have officially published their work! The original research paper, entitled “The Design of Mass Timber Panels as Heat-Exchangers (Dynamic Insulation)” was published in the Frontiers in Built Environment journal. A culmination of two years of investigation and experimentation (see the blog here for more info), the article shows how to optimize mass timber panels as heat-exchangers and suggests how to pair panels with buoyancy ventilation.
Why is that important? The building industry is currently responsible for roughly 40% of global greenhouse gas emissions, with a significant portion originating from the production of construction materials like concrete and steel. Mitigating this climate crisis requires a fundamental shift in what and how we build. Mass timber heat-exchangers offer a potential alternative. Mass timber products are naturally carbon sequestering, and building responsibly with timber has the potential to store carbon in the global carbon sink of new building stocks. Designing panels to be multifunctional provides the opportunity to further multiply savings by suggesting how to eliminate fossil-intensive insulation while simplifying ventilation systems.
Mass Timber heat exchangers aren’t the only alternative – thermal mass is another example of this ‘radical integration’ – but the Mass Breathers and Co are excited to contribute to the conversation, and hope you will too! The article and data are all in the Creative Commons (thank you to MSSI for funding the license), and research is ever ongoing!
Live from behind multiple stacks of full-scale detail drawings, it’s the Thermal Mass and Buoyancy Ventilation Research Project Team! The team has continued their pursuit to draw every detail of the Test Buildings. These drawings have cemented aspects of the building such as cladding, roofing materials, and entryway design. Certainly, there is still much more to decide and conquer. Let’s check out what the team’s got so far.
Concrete Barrier Bargains
First up, a much-needed win for the TMBVRP team; they got concrete barriers! The Cooling Patio, a space for literal chilling underneath the Test Buildings, uses recycled concrete barriers as a retaining wall and seating. Road work being done on Highway 61 in Newbern revealed many of these stackable, concrete barriers just asking to be reused. The construction team doing the roadwork donated and delivered all of the extra concrete barriers straight to Morrisette Campus. However, this generous gift was not the only score for the team. Next, the team found more concrete barriers at the Greensboro Highway Department Office just 10 miles down the road. The Greensboro Highway Department has 40 more barriers and the team can have them if they can move them. Time to start the powerlifting team!
Meanwhile, as the team solidified the material of the Cooling Patio seating, they also came to exterior cladding conclusions. The last post touched on how the team committed to using timber for their open-joint cladding system. Now they have decided on wood species and size. The team chose Cypress in both 6″ and 8″ boards to clad the Test Buildings.Cypress is a locally available and weather-resistant cladding option.
The variation in board sizes allows for more flexibility around complex details. For example underneath the walkway, attached underneath the door, 6″ inch boards come up too short. On the other hand, 8″ boards overhang too much and interfere with the cladding on the Cooling Patio ceiling and Chimney. The mix of boards also allows for board spacing to differ slightly without drawing attention. Uniform board sizes make it easier to spot mistakes and the team is keen on hiding those from you.
A Smattering of Details
Because it would be entirely boring to describe each of these details; the TMBV team will just hit the highlights for you. First, the roofing material will be 1/4″ corrugated metal. While Rural Studio is no stranger to corrugated metal, this is a less common type. Being just 1/4″ in depth, this material has the advantages of durability and low price of normal corrugated metal, but with a more subtle profile. Below, you can see just how that ventilated roof and corrugated metal interact with the cypress clad chimneys and drip edge flashing. These were definitely some of the most complicated details due to the aerodynamic shapes of the chimneys and roof.
Next up is the door. Although the Test Buildings will be used as quasi-dorm rooms for 3rd-year students, the team does not want them appearing too residential. Just in case the polygonal shape and hovering nature of the Test Buildings don’t shout, “Experiment!” loud enough the door has got to be different too. The door acts as a punch through the SIPs wall and Internal Thermal Mass to emphasize that one is entering into an active system. This is done by highlighting the depth of the wall with a thin 13″ aluminum frame, slightly thicker than the wall. This detail was unabashedly stolen from the beloved Newbern Library project, the smart detail treasure trove.
And from the Details, a Mock-up is Born
After drawing and redrawing all those tricky details, Steve Long and Andrew Freear suggested the team practice building them before attempting them on the real deal. This is a time-old tradition at Rural Studio known as the mock-up. A mock-up is a condescended version of a building, or a small part of it, that allows students to practice and visualize construction. For example and as seen above, 20k Ann’s Home Project team built a wonderful mock-up where they tested all their cladding and roofing details to scale. The Thermal Mass and Buoyancy Ventilation Research Project team used this mock-up as inspiration when designing their own. You can take a look at the TMBVRP Test Building mock-up construction document set (CD set) below!
Every detail the team solved can be seen in the mock-up. The entire structure will end up being approximately 6′ x 6′ x 10′. The height is a bit substantial for a mock-up but practicing detailing the chimneys at full scale is very important. The team is making framed walls to the same thickness as the SIPs (Structural Insulated Panels) instead of building with SIPs for the mock-up. This will save a lot of time and money. The team finds the mock-up rather cute on paper though it won’t seem so miniature in person. They plan to start building the mock-up soon, but first, need to gather all the real materials they would use on the Test Buildings. It’s important they practice on something as close to the Test Building design as possible.
The Thermal Mass and Buoyancy Ventilation Research team is happy to be down in the weeds of detailing as their research becomes real. Thanks for Tuning in!
The Thermal Mass and Buoyancy Ventilation Research Project Team have a new design approach which is moving the design along swiftly and with confidence. The team struggled to create cohesive or decisive designs, each member picking small bits of the project such as the cladding or the siting without looking at the total package. While this felt like progress, it was more of going through the motions than collaborative design. Then Andrew Freear threw them a lifeline; draw the whole building(s) in ‘a moment in time’.
The team was to design and choose the best options at that moment for cooling patio arrangement, structural system, site, cladding material, etc. Next, they were to draw and model the whole thing out, details, and all, as a team assuming the chosen parameters. After the team could really evaluate, decide what works and what doesn’t, and design again. Well, Andrew must have had something in his tea that day because the TMBVRP is now on the fast track. In the past two weeks, the developed four design iterations, built two models, and two mock-ups on Morrisette Campus. Let’s take a look at the process and where the design is now!
For the first full design, the team chose the site at the east end of the Supershed. This is a much dryer location than the previous “Two Trees” site. The Test Pods, in this arrangement, act as an extension of the Supershed by mimicking the slope of the roof. By mirroring and offsetting the pods, both rooms have a view from the doorway looking out over Morrisette campus. This offset allows for the access stair to tuck down the side. The walkway between the pods holds them apart and gives a view of the sky from underneath in the Cooling Patio.
Next, the team explored a vertical, ventilated timber siding. This open-joint cladding system shades the SIPs (Structural Insulated Panel) structure from solar heat gain and wraps both chimneys. The structure supporting the Test Pods, while elevating them 10′ off the ground, was a steel frame attached to columns. This steel frame was able to slide underneath both pods between the Downdraft Chimneys. The relatively light steel columns highlight the cantilevered pods. The 1′ thick SIPs’ floors on each pod act as one large beam able to span across the steel structure while distributing the building’s load. All of this allows for an uninterrupted space for the Cooling Patio while making the two pods appear to float.
Reviewing this iteration, the team decided the Cooling Patio head height was entirely too tall for a small gathering space. There is also little interaction with the Downdraft Chimneys in this first scheme. The project collaborators suggested the doors not be above the Downdraft Chimneys to mitigate airflow disturbance. They also pointed out that vertical cladding is less successful for shading than horizontal. With internal and external feedback the team got to work on a new design.
Iteration 2 started with moving the doors from in front of the Downdraft Chimney opening in the pods. This drove the rest of the design because the roof angle is always tied to the chimney locations. The Updraft Chimney, the one on attached to the roof, needs to be on the high side of the sloped roof. This way rain and debris cannot pool around the Updraft Chimney. Also, to distrubute airflow as evenly as possible, the chimneys need to be as far apart as possible. Therefore the Downdraft Chimneys must always correspond to the low side of the roof slope. Switching the roof angle to an “anti-Supershed” slope, allowed for the Downdraft Chimneys to move out from underneath the doors, while keeping the same mirrored, offset pod arrangement.
Whew, the team got the pod arrangement and door to chimney relationship fixed, but they created another problem: structure. The structural steel frame would no longer be able to fit in between the Downdraft Chimneys. So, the team thought to take full advantage of the structural possibilities of the very thick SIPs and attach the columns directly to the underside of the floor. While at first, they thought this would be impossible, their contact at a SIPs manufacturer told them it is done quite often on hunting blinds. “The hunting blind” will go on the long list of nicknames referring to the strange yet recognizable form of the Test Pods. The Tree House, The Periscope, The Wind Catcher….
The cladding, stair, and roof material all took a turn. While the stair and cladding changed direction, the roof material changed from membrane to metal. The roof metal also became the underside material and wrapped corresponding sides of the chimneys. The exterior cladding now acted as a fence around the outer edges of the pods while the metal appeared to wrap underneath. The Cooling Patio height dropped to nine feet, which still seemed a bit high. The team had a good feeling about iteration 2. Mostly, it directed them to give more attention to the Cooling Patio. How does it feel to be in that space? It was also time to see how these Test Pods really looked on Morrisette Campus, not just in model.
First, photomontages, collages of model photos and site photos, were created to get an estimate of just how big these pods look on site. The results are in: the pods are pretty dang big. There was also a slight column movement from the last iteration, but that’s a very boring drawing. These images really got the team thinking they needed more visualization. So it was time to build a mock-up.
This one-day mock-up tested the height of the Cooling Patio space, seating arrangements, and pod siting. The columns are accurately placed and support a frame that represents the underside of the pods. This gives the relative ceiling height of the Cooling Patio. The team first built the columns and frames to give a head height of 8′ 6″. They pretty immediately lowered it to 7′ 6″ as it still felt too generous for an intimate space of gathering.
The mock-up helped to establish an undercroft ceiling height but revealed some disfunction between all of the elements in the space. The team needed a more robust mock-up to understand how the retaining walls, seating arrangements, columns, and Downdraft Chimneys interacted. Plus, the team had a really good time building. It was off to Lowe’s for Iteration 4 and Mock-up 2.
Before getting to Mock-Up 2, let’s address lateral load. While the columns can be specified to support the weight of the buildings, what will keep the Test Pods from tipping over in the next high wind storm? For iteration 4, the idea was to tie all the columns together underground in the foundation. That foundation than extruded upward to become the retaining wall and the support for the seating. Seating as a way to gather around the cool-air chimneys, which act as spacial barriers, drove the placement of the walls and columns. The resulting design was translated to Mock-Up 2.
The biggest worry about iteration 4 was the distance between and size of the chimneys. However, sitting in the complete Mock-Up 2 space, the chimneys did not feel too crowded or large. Instead, they felt like the integral feature they are. They divided the space into three but still allowed for continuity, through access, and visibility. The space between the chimneys is more compact and private while the larger spaces at the Cooling Patio entries allow for gathering.
The ground to sky connections really began to stand out in the photomontages of iteration 4. This brought to mind both material pallet and column placement. While the team originally thought the benches in the Cooling Patio might be light, thin material, it became quite clear it should be something heavier. This way the Cooling Patio is clearly an element of the ground, while the pods are an element of the sky. This idea also brings into question whether the columns always hitting the foundation/retaining wall perfect actually makes them stand out more. A regular, orthogonal placement, while still keeping clear of the gathering space, may make the columns somewhat disappear.
The Thermal Mass and Buoyancy Ventilation Team is moving on to iteration 5, 6, 7, on and on. They are enjoying their new design process as the idea of building these two floating experiments becomes more real every day. Next up, the team is taking a deep dive into the interior of the pods. Thanks for reading and don’t forget to take it one moment at a time and STAY TUNED!
Exciting news from Hale County: the Breathing Wall Mass Timber Research Project (BWMT) test building construction is complete! Last week Fergie and Preston finalized the construction of two mass timber test buildings on Rural Studio’s campus. These test buildings will be used in the future for research on the breathing wall, thermal mass, and mass timber. The team is also in the peer review process for their scientific paper on their small-scale experiments. It’s been a busy two years!
As a quick update, these two mass timber buildings are the result of two years of design and experimentation on mass timber systems and their potential integration with breathing wall technology. The floors, walls, and ceilings are all dry-stacked timber compressed with threaded rods to ensure an air-tight envelope. All of the steel components were designed and fabricated to facilitate the BWMT experiment: a steel roof acts an umbrella to protect against solar radiation and wind-driven rain; doors are hung from the top on the exterior to adjust to expanding timber; and steel plates and angles spread pressure from the threaded rods evenly through the timber. On the interior, flexible loft spaces are accompanied by fabricated railings and ladders, with a simple conduit carrying all electrical and lighting. The entire project was designed with flexibility in mind, so they can be used for future experimentation. The goal isn’t that these buildings are precious, but that they’re useful.
The past two years have definitely been a learning experience – doing scientific research at an architecture school was difficult at times, but the tension between the two really propelled the team and the project. The team learned to leverage the scientific aspect to inform their architectural decisions and to use their architectural knowledge to keep the research grounded. In the end, the design was stronger because it was backed by actual research; science and architecture can and should go together.
The team would like to thank the many reviewers and supporters who helped further this project for the past two years. Thank you to the Rural Studio faculty and staff, particularly Andrew Freear and Steve Long. Thank you to all who donated gifts, materials, and time. Thank you to the team’s studiomates, friends, and family for the constant support. Thank you to the Newbern community for welcoming the team in and taking them under their wings. And huge thank you to Salmaan Craig and Kiel Moe at McGill University and David Kennedy at Auburn University who volunteered their time each week to invest in and further this research.
Rural Studio is a place filled with magic and the team was extremely thankful to have been a small part of it for the past two years. The team served not only as students but community members, scientists, buildings, chefs, and farmers (to name a few.) They gained an understanding of the importance of being a part of the place and the community. All four team members are committed to taking what was learned in and out of the classroom forward with them as they move on from Hale County.
As for the team, Jake has been in New Orleans researching mass timber as a Research Fellow for Eskew+Dumez+Ripple. Anna is pursuing her PhD at McGill University furthering the study of the Breathing Wall. Fergie and Preston are moving to the mountains of Colorado to chase some design-build dreams. The team looks forward to the many visits back to Hale County and Rural Studio. That’s a wrap!