Killarney House: Carbon Neutral Living

Intro

Our first CarbonShack. This house is a comprehensive prototype for a new definition of green building. By integrating principles of high efficiency, low-impact materials, and natural aesthetics, this house provides environmental solutions for the variety of issues that remain unresolved by conventional green design.

Heating and Cooling

Specs: Heat Pump SEER 19.3 & HSPF 9.5. Energy Star. Saves 0.96 tons of CO2/yr.

Heating and cooling is the largest consumer of energy in a house. So, if you are building a new house or shopping around for efficient appliances, this is where to start. The most efficient way to heat and cool your house is by avoiding the use of standard equipment altogether.

To avoid the use of standard equipment, we installed a whole house fan for cooling and ceiling fans for heating. By pulling air from inside the house and expelling it outdoors, whole house fans rapidly cool a house down and are perfect for summer evenings when temperatures drop. Contrary to popular belief, ceiling fans don’t cool, but instead heat rooms. As fans run, they circulate the warmer air that naturally rises towards the ceiling, reducing the need to run heating equipment.

Framing

Saved 2.76 tons of CO2

Each year, 48% of wood in the construction and demolition waste stream is available for recovery, yet it continues to be hauled to the dump. While it’s becoming more common to use reclaimed wood for finishes and furniture, why not use the same knowledge to build a house out of reclaimed wood? Rather than downcycling the material into a finish, which guarantees only one more use, why not upcycle the material by preserving its integrity as structural lumber, allowing it to be used for several more lifetimes?

Insulation

Specs: R25 Walls | R48 Ceiling | R19 Floor. Saves 0.49 tons of CO2/yr

Installing high quality insulation is critical to having a house perform as efficiently as possible. The thicker the insulation, the better it is at resisting the flow of heat from the ambient air to the inside of a building. Using reclaimed wood, however, posed a serious issue. While today’s lumber in high performance homes is commonly six inches or thicker, the lumber used a century ago was only four inches thick. Of course, these one hundred year old houses are the ones marked for demolition in Los Angeles. To get around this problem, we built double stud walls. For each wall of the house, instead of one frame, we built two with additional space in the middle. Once both four inch frames were constructed, they were insulated with over 8 inches of insulation.

Finishes and Design

Finishes, like structural construction materials, have specific carbon footprints. But, unlike materials such as wood framing, or concrete foundations, finishes serve another purpose. While framing is hidden behind walls, finishes remain in the open and are designed for us to look at, touch, and interact with. Therefore, the environmental benefit of a finish can be twofold. The first benefit can be selecting a finish that has a low carbon footprint. The second benefit can be crafting a finish that empowers homeowners to be responsible operators and stewards for the entirety of a building’s life. It is not uncommon to hear a story about a home designed with a true understanding of energy principles and outfitted with state-of-the-art equipment that is underperforming. While every principle can be followed during design and construction, if homeowners aren’t educated to operate the home efficiently, such as turning off lights or closing windows completely, the home will never truly be green. Finishes have the ability to motivate people to make these necessary steps.

Appliances and Lighting

Specs: Fridge: 2 units 275 kWh rated each. Energy Star. Saves 0.09 tons of CO2/yr.
Dishwasher: 199 kWh rated. Energy Star. Saves 0.03 tons of CO2/yr.
Clothes Washer MEF: 2.6 WF: 3.3. Energy Star. Saves 0.01 tons of CO2/yr.
Stove: Induction Cooktop. Saves 0.03 tons of CO2/yr.
Lighting: 100% LED. Saves 0.15 tons of CO2/yr.

Most EnergyStar appliances were installed. EnergyStar offers a thorough and transparent guide for refrigerators, dishwashers, clothes washers, and clothes dryers. Refrigerators are the largest energy hogs out of all the appliances, so this was the appliance with largest priority. Because we are in Southern California, we also decided to focus on clothes washers and dishwashers with models that used little water. Currently, there remains no EnergyStar label for stoves. While they remain fringe in the United States, the most efficient option for home cooking is an induction cooktop. Induction cooktops transfer 90% of heat energy into food, compared to the conventional electric cooktops, which transfer 74% of heat or 40% for gas.

Countertops

Saved 0.02 tons of CO2

While stone countertops are standard in homes today, large slabs of well-kept stone is challenging to find, making it nearly impossible to salvage. Furthermore, new stone has a high carbon footprint. Stone must be quarried, which requires heavy machinery and blasting, and leads to land clearing, backfilling, and generates large amounts of scrap and waste. Plus, much of the stone we use is from Brazil, India, and China, resulting in high transportation costs. After extraction and transportation, the raw material must be cut, sized, and shined, which is extremely extensive given the variety of steps and machines needed. Diamond wire cutters, chainsaws, hydraulic jacks, and splitting wedges are just a few of the machines needed to create a single countertop.

Much of the impact can be reduced by choosing a different material. Partnering with a company up the coast in the Pacific Northwest, they provided a countertop material that mimicked stone, but was made out of recycled paper. This decision eliminated the extraction footprint, decreased the transport footprint, and reduced the manufacturing footprint.

Cabinets & Millwork

Saved 0.05 tons of CO2

Both the bench and cabinets are crafted out of reclaimed wood, the most environmentally friendly material. The wood salvaged to make the bench did not come from a home, but instead came from a church. The wood is old growth Philippine mahogany that was saved from a pew inside a Santa Monica chapel marked for demolition. Not wanting to downcycle structural lumber into furniture, we were able to repurpose existing furniture. This wood was then carved into intricate patterns depicting structural plant elements ranging from the subcellular to multicellular level. These designs can be read about below. With extra mahogany remaining, we converted the rest into kitchen cabinets. This mahogany was supplemented with reclaimed Douglas Fir that was also unsuitable for framing.

Plant Evolution

Engraved into our reclaimed mahogany bench is a frieze of structural plant elements, ranging from the subcellular level to the multicellular level. These elements evolved several billion years apart from one another, yet they are linked by the theme of photosynthesis. The frieze begins with a single chloroplast. In this cellular organelle, light enters and aided only by water and CO2, the plant is able to convert this sunlight through a series of reactions into sugar. This process evolved billions of years ago, not in plants, but in cyanobacteria. The chloroplast in cyanobacteria was then engulfed by an algae, the ancestor of plants, and instead of being digested, it was integrated into the cell. Over the course of billions of years, plants became large multicellular organisms with complex tubing with the ability to transport sugars to far off places such as roots and bring the necessary reaction ingredients, such as water, to chloroplasts. This is known as the plant’s vascular system, which occupies the second half of the frieze. Vascular systems have been critical in determining how much energy a plant can store, and how large it can become. Photosynthesis is one of the most fascinating phenomena found in the natural world, which can be studied with the naked eye, within a cell, or on an atmospheric level. While it all began inside of a single cellular organism, it has fundamentally altered the fabric of life and the surface chemistry of the earth, with its byproduct, oxygen. Before photosynthesis, there was relatively little oxygen in the air. The evolution of this organelle in cyanobacteria was so successful, and became so abundant that it increased oxygen levels so radically, killing most existing life on earth at the time, including itself, and paving ways for new forms of life that rely on oxygen such as humans. This frieze is a reminder that humans are not an exception to the natural world. We are far from the first species to change the atmosphere of earth. However, it is a warning. The chemical changes we are making may threaten our fate. While the earth has gone through many drastic climate change events before, our civilization has not. The earth, and life as a whole will be fine. Instead, we are the ones in danger.

Fuel Use

Specs: All Electric Space Conditioning and Water Heating.

Using less traditional mechanical equipment, such as space heat pumps and water heat pumps allows us to fuel our home in a less traditional way. Today, the majority of homes in the United States use natural gas to power their space heating and water heating equipment. Instead of following suit, we decided to power our house using only electricity. Several things contributed to this decision.

Rooftop Solar and Battery

Specs: 7 kW Polycrystalline Rooftop Photovoltaic System. Saves 3.03 tons of CO2/yr.

We installed a 7kW rooftop solar system with battery storage. While solar used to be a luxury item, costs have plummeted, making it an affordable option. Over the past decade, the cost of solar modules have fallen 82% and the global community has responded, with solar growing 45 fold in this time. Not only has solar become cost effective, but the price of batteries for energy storage has been decreasing rapidly.

Water Fixtures

Specs: Low Flow Faucets, Low Flow Showerhead, Motion Control Faucets, Waterless Urinal. Saves 0.03 tons of CO2/yr.

A drop of water in Southern California is far more carbon intensive than the National Average. While water may be secondary to energy in most parts of the country, it is an equal priority in Los Angeles. To minimize our water use, all fixtures were low flow including our faucets and showerheads. We decided to use a waterless urinal, which is unconventional for a house. But, toilets remain the largest indoor water consumer, using roughly one quarter of water, so we felt going unconventional was necessary. We also installed motion control sensors to minimize any occupant errors. While light sensors are becoming increasingly common in households, and have led to significant savings, water sensors remain taboo. If it has worked for light sensors, why not experiment with water? We are hoping these sensors will minimize leaks and occupant errors.

The Human Microbiome

A symbiotic relationship that has been of emerging importance over the last decade has been our own microbiome. Constituting 90% of the cells in our body, these alien species play an integral role in digestion and immune function. Like mycorrhizal fungi and trees, we are not individuals disconnected from the natural world, rather we are an interconnected and interdependent community of organisms. Without a community of internal bacteria, we could not exist. To display this internal natural community, we designed the tile in one bathroom as if it were a room full of e-coli bacteria. This use of domestic design to reflect larger societal values is not new and one has to only look back at the Craftsman period to see this. Germ theory was postulated in the 1880’s by Louis Pasteur. He proposed the radical idea that disease could be controlled through sterilization. This along with the influenza pandemic of 1918, when an estimated 500 million people worldwide died, about one-third of the world’s population, created radical changes in domestic architecture. Bathrooms, kitchens and even toilets, which used wood extensively in the Victorian Period, shifted exclusively to white tile and porcelain so that when the next influenza virus swept the globe critical surfaces could be wiped down. Kitchens and baths from the period were even referred to as “laboratories”. Our e-coli tile designs stress that it is an oversimplification to label bacteria as dangerous or unsanitary. The essential function bacteria plays within us is synonymous to the symbiotic relationships seen throughout the natural world. While we are inclined to categorize natural or industrial elements as good or bad, we miss the intricacies that we could otherwise learn from. Biology is full of paradoxes and anomalies, but understanding both the rules and the exceptions are crucial to becoming more attuned to the complexities of a changing climate.

Water Heating

Specs: Solar Water Heater: 0.87 SF. Energy Star.
Heat Pump Water Heater: 3.05 EF. Energy Star.
Saves 0.71 tons of CO2/yr.

Water heating is the second largest consumer of energy in a house after space heating. There are a variety of water heaters, ranging in efficiency. We chose to use a solar hot water heater. Rather than an electrical appliance that is powered by a solar panel, a solar hot water heater works by using the sun’s energy to heat up a liquid in a tube, which is then transferred to coils within a tank, heating up the water. No electricity or fossil fuels needed. We then installed a backup water heater to ensure that there is enough hot water being generated in the winter months. Our type of backup water heater is called a heat pump water heater. Just like space conditioning heat pumps, water heat pumps use the same technology. Out of the variety of different water heaters, heat pump water heaters are far more efficient than standard electric or gas water heaters. Because heat pumps are electric, this energy will be coming from our rooftop solar panels. You can read more about our fuel use and solar panels below.

Mycorrhizal Fungi

Patterns of fungi are featured throughout the house in tile, engravings, light fixtures, our front door, and fabrics in a variety of forms. Rather than abiding to the traditional patterns found in homes, this theme was chosen to offer occupants a less conventional message. The fungal patterns represent mycorrhizal fungi, or fungi that are paired in a symbiotic relationship with plants.m down into a readily useable form. While plants have the ability to harvest sunlight to produce sugars via photosynthesis, fungi have no such structure, making sugar a valuable commodity. In return for supplying nut Living in the roots, essential nutrients are supplied to the tree by fungi. Being the decomposers, or the recyclers, of the forest floor, fungi have the ability to efficiently find decaying material, extract the nutrients, and break therients to the tree, the tree shares the sugar it produces. This symbiotic relationship is seen in rainforests across the Amazon. Unfortunately, when trees are removed from an area, the fungi disappear and when vegetation begins to repopulate, tress are unable to grow, making the land only suitable for grasses. The patterns of fungal spores, the reproductive structures fungi cast to promote offspring, and mycelium, the dominant structure a fungi spends its life in, remind us that the natural world is not just a place of competition. Instead, symbiosis, both between and among species plays an equally important role. If we hope to survive as a species, we must learn how to adopt the symbiotic relationships that are abundant in the natural world sooner rather than later.

Interior Wall Finishes

In the bedrooms, the walls and ceilings are paneled with reclaimed, old growth redwood. This ancient wood, which can’t be purchased new anymore was salvaged from a bridge in Northern California that had been decommissioned and was marked for demolition. While using reclaimed wood is the most environmentally sound interior wall finish, wood paneling is extremely expensive.

Textiles

Saved 0.77 tons of CO2

Choosing a sustainable textile often comes up when buying clothing, but is rarely a subject when furnishing the interior of a home. While clothing does make up the largest share of the textile market accounting for 45%, household and interior textiles are second, comprising 35% of the global market. This results in a global footprint of 242 million tons of CO2 emissions every year.

Foundation

Saved 0 tons of CO2

Concrete production is responsible for 5 to 8% of global emissions. To put this in perspective, the carbon impact is comparable to that of Russia on the low end, or the entire European Union on the high end. This high global footprint is largely due to an enormous demand. It is a fundamental building material, found underneath every home. Tackling the problem is particularly important in Los Angeles, because hillside building and earthquake control forces us to use tons of concrete every project.

In addition to the high level of consumption, the material has a high inherent footprint. Cement, the glue-like material in concrete, is where the issue lies. Cement manufacturing requires intensive industrial kilns. Moreover, when cement is created, it undergoes a chemical reaction that releases CO2 as a natural byproduct, which accounts for over half of its carbon footprint. This means that even if we power all manufacturing technology with renewables, over 50% of its carbon footprint remains.

The solution is to replace cement without reducing the integrity of the concrete. To do this, there are cement-like products called fly ash and blast furnace slag. These products are industrial waste materials that can be substituted into concrete in lieu of using cement. It is standard for the industry to use 10% of these products in all mixes.

The key is to use fly ash in a high volume, which means using 30% or more in a concrete mix. The benefit is twofold. One, it reduces the amount of cement needed. Two, it’s a toxic industrial byproduct that is difficult and costly to dispose of. Mixing it in with cement, however, makes the substance inert, locking it in a non-toxic form. Unfortunately, our foundation was poured using a standard 10% fly ash mix. We were, however, successful in using a 30% fly ash mix for large retaining walls that were needed to secure the hillside. While no structural issues arise using 30% fly ash mixes, the lack of familiarity in the construction industry deters vendors from wanting to approve such mixes. Our largest issue was convincing subcontractors that these high volume fly ash mixes were safe. Once our vendors gained familiarity, however, using a 30% mix became standard for all projects.

Because fly ash is a coal byproduct, a new substitute will be needed soon. With coal plants going offline, fly ash production will wane, which is undoubtedly good. For future projects, we are looking at emerging technology that goes beyond waste substitutes. A technology called carbon capture storage, or CCS, grabs industrial CO2 in smoke stacks, and pumps it into concrete for it to be stored. This not only sequesters CO2 that would be in the atmosphere, but the CO2 itself acts as a cement substitute. Once a manufacturer comes to our region, we hope to partner and use CCS in conjunction with high volume fly ash. In the meantime, we have been collaborating with engineers to design foundations that demand minimal concrete, and have been experimenting with ways to substitute the use of cement for other structural materials, such as glulam lumber.

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Flooring

Saved 0.23 tons of CO2

The floors were designed from a combination of tile and reclaimed wood. We used the same tile company that had produced our wall tiles for aesthetic continuity. The wood came from old Douglas Fir that was reclaimed from houses we had salvaged. While we preserved all usable framing material for future framing uses, to prevent downcycling, much of the salvaged wood was either under four feet or much too thin to be used for structural purposes. Instead of hauling this wood to the dump, we repurposed it with tile, making a flooring material that could last as long as a building remains standing.

Roofing

Saved 6.54 tons of CO2

Given the Spanish revival style of the house, we chose to use terracotta roof tiles. Out of all roofing materials, clay tile has the highest carbon footprint. To create a single tile, clay must be mined, refined, and fired at 2000 degrees Fahrenheit. This process is mostly done outside of the United States, where environmental protection laws are looser, which means firing is often in older kilns that release higher levels of CO2 and produce more toxins. Luckily, being in Los Angeles, there is no shortage of clay tiles waiting to be salvaged. Throughout years of finding old houses to salvage, we have recovered thousands of clay tiles.

Exterior Siding

Saved 4.56 tons of CO2

We used a variety of siding materials. Roughly one third of the house is coated in stucco, another third is shingled with wood, and the last third is a mixture of stone and brick.

Stucco was applied on the facade of the house closest to the park. We felt it was necessary to use stucco in this area, due to its flame retardant qualities. The wildlife-urban interface, or WUI, is a growing issue, and is pervasive in California. The increasing WUI and hotter annual temperatures creates higher fire risks, both for households and conserved land. With this natural layer of protection, if a fire is either in the park, or in the house, it will prevent the fire spreading from one area to the other.

Home Automation

While we have crossed our t’s and dotted our i’s in terms of making this house as efficient as possible, occupants that lack the knowhow or habits to operate homes efficiently can quickly undo all these measures. While we hope to empower occupants and make homeowners not just understand how to live green, but take pride in it, we realize this is not everyone’s first priority. To circumvent this issue, we collaborated with several engineers to automate the home, ensuring maximal performance no matter who the operator may be.

Landscaping

As stated early, water in Southern California is far more carbon intensive than the National Average. Furthermore, because of the dryness and high annual temperatures, a conventional landscape demands more water in California than in most regions of the country. To reduce water usage, we took several measures. The first, and best measure is to reduce landscaping water needs by using drought tolerant plants. We landscaped the area with varieties of native grasses and trees. Next, we created large underground cisterns to collect and hold rainwater, which could then be used during dry periods.