Octothorpe House – Merit Award

2023 DESIGN AWARD RECIPIENT

Octothorpe House – Merit Award

Octothorpe House’s double-crossed plan allows for a continuous flow within the house. Occupants can walk in an infinite loop around the central courtyard of the home. The flexible plan allows for an easy separation between public and private zones for the family and guests. The efficient house has no corridors; rather a series of rooms following one and another.

The unusual octothorpe (hashtag) shaped plan creates connections between the indoor and outdoor spaces, with 1 contained and 7 semi-contained courtyard spaces for varying weather and wind conditions. Almost every room has access to its own outdoor space or niche. The morphology of the plan combined with porosity of the glass creates outward views but also site-lines throughout the house itself, looking through the courtyard space to see larger views, or down corridors which creates an expansiveness and connection to the outdoors.

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The layout is inventive and a new way of looking at the space distribution of single-family homes. The material palette moves away from the opulence that has become common in current residential design, which is refreshing. Elegantly detailed.

Noteworthy performance features include:

1. Uses CLT timber construction as exterior cladding, walls and ceilings.

//framework for design excellence measures

Measure 1: Design for Integration

The primary approach to sustainability via design came in the form of designing a home from Cross-Laminated Timber. CLT is made from sustainably harvested SFI/COC grown wood that is glued / laminated using low-VOC adhesive. The interior walls of the house are almost exclusively cross laminated panels made of pine, spruce, and fir with a natural oiled finish (with the exception of bathroom wet areas that are tiled), resulting in great acoustic and air qualities. CLT construction is a low-waste / high efficiency construction method, resulting in very little on-site waste and efficient recycling in factory. Due to its CLT construction, this project has a projected 25 ton carbon embodiment within its walls, and a projected 15 metric tons of greenhouse gas emissions avoided. The home’s criss-cross shaped plan creates natural cross-ventilation strategy for cooling in the warmer months, and also integrates operable concealed solar shades to protect the south facing rooms from the intense Oregon high-desert sun.

Measure 2: Design for Equitable Communities

The car has an electric charging station. The owners also both use electric cargo bikes to commute in to town for daily errands and taking their child to school.

Measure 3: Design for Ecosystems

The intent was that the project would facilitate regrowth of pre-existing plants after a wildfire cleared the site 20 years ago. Local plants were used throughout the site to blend in with the natural high desert environment as well as conserve water. After the initial growth period, the plants do not require watering.

Measure 4: Design for Water

The use of local plants was the main driver in the water conservation for this project. As it is in a high desert climate, the plants chosen are appropriate for the arid climate. Storm water catchment was calculated for this high-desert home in the event of 100 year storms which could result in up to 7 ” of rainfall within 24 hours. A gravel dissipation basin of 580 cubic feet is designed to accomodate (requirement was 362 cubic feet).

Measure 5: Design for Economy

Because of its neatly organized plan, the house has no corridors; rather a series of rooms following one and another. Thus, the occupants are using all of their area effectively. One of the guest rooms has a hidden Murphy bed, creating an office for the work-from-home couple when they are guest-free. The home’s enclosed central courtyard, visible from most rooms, doubles as a protected outdoor playground for the couple’s young son. In the winter, the large garage space doubles as an indoor playroom.

Measure 6: Design for Energy

The building planned to accomodate geothermal heating and cooling, which has not yet been installed due to the installation costs. The home is equipped with hydronic floor heating in the concrete floors which is used to efficiently heat the home with hot water and is ready to retrofit geothermal heating and cooling if it proves to be realistic in the future. Further it was decided to not have onsite renewables due to a full renewable energy offer from the power company. This solution is more economical and also supports the public investment in renewable energy.

Measure 7: Design for Well-Being

The project is focused on using natural materials. The exposed CLT elements in the interior create a healthy indoor environment. The only constituents of a CLT building system are wood and non-toxic/non-VOC adhesive. CLT does not introduce any toxins into the indoor environment, providing clean indoor air quality. The final surfaces of all interior walls were left in their natural wood state sealed with a protective natural oil, instead of applying gyp board or paint, to promote better air and acoustic qualities. Natural light as well as ventilation were also important design drivers.

Measure 8: Design for Resources

The key design driver for this project was using cross laminated timber. The CLT was manufactured from small and medium diameter timber harvested in sustainably managed forests. In addition to excellent thermal performance, CLT provides other benefits, most obviously that wood is a natural and renewable building material. Trees absorb carbon while growing, and wood stores carbon both in use and in landfill. The CLT manufacturing process uses significantly less energy than concrete and steel, also reducing emissions. Finally, because CLT panels are made and pre-cut in factories, waste is minimized, responsibly disposed of, and recirculated where possible.

Measure 9: Design for Change

This house was designed utilizing Cross Laminated Timber Panels which were prefabricated in a factory to shorten the length of building time. The massive timber assist in the thermal insulation of the project. The house is clad in Shou Sugi Ban, which is a burned cedar wood. Shou Sugi Ban is fire resistant, low-maintenance, water-proof, resistant to decay and insects, and has a significantly longer lifespan than untreated or stained wood.

Measure 10: Design for Discovery

The main challenge learned in this project was the length of construction. The homeowner anticipated an accelerated “pre-fab” type construction and executing the assembly and coordination of the CLT home proved more complicated than the selected builder was prepared for. Lesson learned: when being an “early adopter” of a new technology, ensure that the contractor is well-prepared and informed, and trained to execute the type of construction that the project design demands.