Design Build Bluff is excited to announce the completion of Little Water, its 13th house.
The home was completed this past May of 2012. The crew of 12 University of Utah student’s named Little water after the surrounding region. Recipients of this semester’s build were Ben and Sara Jones. Little Water is a unique addition to the Design Build Bluff family as it is ADA accessible. As an elderly couple with limited mobility, Ben and Sara required full ADA-accessibility to accommodate their needs, a DesignBuildBLUFF first. Completed in just over five months, the 1,060 square foot Little Water features two bedrooms, one ADA bathroom/shower and an open kitchen/living space. Spirits were high as all the hard work the students endured commenced in a celebratory dinner party with Ben and Sara.
The student’s goals were to explore and experiment with passive heating and cooling techniques. Overall, the students designed five different systems to ensure the house would function in both winter and summer. These explorations include an insulated thermal berm wall, a straw bale wall, a solar oculus for natural ventilation and cooling, a ventilated second roof and a rocket stove.
The berm wall was not only an aesthetic design decision but also a way to moderate temperature as well as protect the structural block wall from expansion and compression with temperature change. In order to do so, the berm needed to be fully insulated. In section, the berm was built up part way with soil and then covered with a series of layers, all contributing to overall function of the wall. The bottom layer of soil was covered with straw, cardboard, a waterproofing membrane, foam, landscape cloth, gravel and finally a 3’ layer of top soil. Terraces were added and necessary to prevent the berm from erosion and washing away.
The other exterior walls are R-36 insulated straw bale. This straw bale wall acts as a thermal barrier holding heat in during the winter and keeping heat out during the summer. Here in Bluff we are able to gather clay locally which was used to finish the interior and exterior straw bales with a natural earth plaster.
The solar oculus is designed aesthetically as a light well and functionally as a natural ventilation system. During the hot summer, the lower clear story windows and oculus vents can be opened and through the properties of ventilation, allow the hot air to escape from the oculus vents.. As a back up cooling method, an evaporative cooling system was installed with ducts running through the berm and into the house much similar to earth tubes. The air circulated into the house will be cooled by both the evaporative cooler and the earth in the berm.
In addition to these systems, a secondary roof structure provides an air barrier between the metal finished roof and the building envelope’s roof structure. As the finished roof heats throughout the day, the air barrier blocks heat from being absorbed into the house.
The heating source for Little Water is a mass rocket stove constructed of earth block and cob. This stove requires only small pieces of wood as the fuel source. The exhaust heat from the fire is drawn through 35’ of stove pipe that runs inside the clay bench. As the heat travels through the stove pipe, it radiates through the bench. After several hours of burning, the entire block bench will have absorbed enough heat to radiate into the surrounding areas.
Final images of the house were taken by Park City photographer Scot Zimmerman. Design Build Bluff would like to thank Scot for donating his time and photographs to our program! These images can be found on our Blog as well as Facebook page.