passivehouse

Getting Down to the Details Episode II: Attack of the Drawings

diagram of Test Building showing all details the team must draw

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!

Cladding Conclusions

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.

Pod cross section showing cypress cladding system

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.

cut section through door showing door frame and walkway connection
full door section showing walkway connection

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!

Axon and Axon section drawings of the pod mock ups

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!

Auburn Opelika Habitat Homes

A major goal of the Front Porch Initiative is to expand home ownership in areas outside Rural Studio’s service area of West Alabama. Recently, we collaborated with another studio within Auburn University’s School of Architecture, Planning and Landscape Architecture (APLA) and the McWhorter School of Building Science (BSCI) as well as Auburn Opelika Habitat for Humanity to build two homes in Opelika, Alabama. The design of these two projects is based on 20K Buster’s Home. The homes for this collaboration were optimized for energy efficiency using different efficiency standards, which offers the opportunity to study two models of energy consumption. Additionally, both homes are designed to provide beyond-code resistance to damage from high winds and blowing rains.

View of a 20K/Front Porch home at sunset with the lights on
House 66 Dedication – Image by Matt Hall

The first house, dubbed House 66, is Passive House Institute US (PHIUS) certified, which requires homes to be super-insulated, minimize air leakage through a tight envelope, have high-efficiency windows and doors, active ventilation, and energy efficient equipment. The house was also built to the Insurance Institute for Business and Home Safety’s FORTIFIED Home – High Wind standard, which certifies that a home’s construction strengthens it against severe weather. House 66 is the first home in Alabama to receive PHIUS certification and, as far as we know, the only house in the country ever certified both PHIUS and FORTIFIED Gold. The second house, House 68, is built to Zero Energy Ready Homes (ZERH) and FORTIFIED standards. Though not as stringent as PHIUS, ZERH also focuses on energy efficiency and preparing the home to adapt to renewable energy sources as they become available. Both House 66 and House 68 have a HERS rating of 38 (learn more about the HERS index here), but our energy models predict that it will cost approximately $100 more in energy costs per year to operate House 68. These costs can further offset by the installation of a photovoltaic (PV) panels, also known as solar panels, which generate energy. A PV system has already been installed at House 66, where excess energy produced is fed into the local energy grid.

Each house is also outfitted with monitoring devices to collect data about energy usage at the level of the individual circuit. David Hinson of APLA is co-leading the project and explains the research: “We will monitor the actual operating costs […] and compare the operating savings against the cost of incorporating these special features. Our aim is to find the balance point between the initial cost of constructing the home and lower operating costs that results in the best long-term solution for the families.” Along with Hinson, Mike Hosey of BSCI and Mackenzie Stagg of the Front Porch Initiative have received funding to analyze the data collected at the homes. Analysis of this data will help us better understand which changes to the building design have the largest impacts on energy consumption.

Habitat House 68 exterior
House 68 Dedication

Awards:

At the 2019 PHIUS Passive House Projects Competition, House 66 was awarded Winner of the Affordable Category.

Recent Press:

Auburn University 2019 Press Release: Building Better Architects: Auburn University partnership with Habitat for Humanity gives architecture students experiential learning opportunities

Auburn University 2018 Press Release: Auburn University students design, build energy efficient Habitat for Humanity Home

WLTZ News: Auburn University Students Help Design Energy Efficient Habitat for Humanity Homes

Opelika-Auburn News: Opelika takes step toward renewable energy

Learn more about the Front Porch Initiative here.