The Builder’s Notes

In part one of this post, we asked if radiant under-floor heat makes sense for a high-performance, passive home. (Read Part One here.) The Overheating Debate Executive editor of Environmental Building News, Alex Wilson’s opinion is clear: radiant floors don’t make sense for passive homes. Overheating is one of many concerns: In a home with a tight envelope and a very small heating load, even a small amount of heat can cause overheating, and the thermal mass in a radiant floor system increases the risk. This is particularly true in buildings with some level of passive solar gain – the radiant...


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Few other heating methods get people so excited as do radiant floors – and for good reason. The delight of going barefoot on a warm surface is hard to beat. Think of a warm hardwood deck on a chilly day... or a picnic on a sun-baked rock. Radiant floors bring the pleasure home, heating your floor directly, which then radiates warmth into the room for a thoroughly comfortable atmosphere. A fantastic idea. But in a passive house – one that’s super-insulated and highly efficient, such as the homes we build at Clarum – does the idea hold up to reality? Our Radiant Experiment Between...


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The choice of healthy construction materials became a major issue in the mid-twentieth century, as builders began using toxic, artificial products, while also sealing buildings as tightly as they could. Sealed buildings conserve energy, of course. However, they also trap harmful gases. When toxic materials are used in construction, indoor air quality can actually reach urban pollution levels. The culprit is VOCs, or volatile organic compounds. Products high in VOCs continue off-gassing long after they’re installed, damaging your long-term health and bearing a daily impact on your your mental...


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Sunday, April 28th from 1:00 - 5:00pm 840 Los Altos Avenue, Los Altos, CA Free tour! No tickets or reservations required. Join us and experience a passive-inspired modern home first hand. The future of modern is a stunning merger of high-performance, energy efficient construction and contemporary architecture. Tour this green home and see how Clarum Homes seamlessly blends sustainability with sophisticated design. Don't miss out! This is a one-day opportunity to immerse yourself in a truly modern living experience. About the Home Approximately 3,800 square feet, this single-story...


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The quality of the air you breathe may not often come to mind. But given the impact it has on your everyday, it’s hard to exaggerate its importance. Most homes are built from construction materials that steadily off-gas over their lifespan; these pollutants aren’t healthy or comfortable to breathe. Neither is air that’s heavy and stale. Ventilation addresses both problems; it also goes further: Removes unwanted smells (cooking, pets, etc.) Controls moisture, protecting your walls, floors and belongings Prevents mold and keeps pollutants from damaging your health Helps you focus;...


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In the natural world mold serves a valuable role, helping decompose dead organic matter: fallen trees for example. Inside the home, however, it’s anything but healthy. Mold produces allergens, irritants, even toxic substances, and can cause serious health problems. Mold spores can be found almost anywhere; these aren’t harmful in themselves. The problems arise only where they can find a moist place to grow. So, the key to preventing mold? Controlling moisture. Control Moisture, Prevent Mold Interior Sealing We take care to seal all the wall joints and penetrations comprehensively at Clarum...


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Adhesives are everywhere. Cabinets and counters, sub-floors and carpets. Paints and stains. Bath tubs, moldings, baseboards... Each of these elements requires adhesive or caulk for installation. In fact, few other building materials are so common as adhesives. Yet most of the adhesives used in a conventional home are highly toxic. At Clarum we call that a problem. Invisible as the Air you Breathe Many adhesives use volatile emulsifiers to give them a liquid texture during application. After drying, these volatile organic compounds (VOCs) slowly evaporate at room temperature – bringing...


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Carbon monoxide in close quarters? That’s a conventional garage. Vehicle emissions in a closed room are dangerous, of course. Clearly this is a concern for anyone who likes to spend time in the garage – but also even for those who don’t. Every time you open the door to your attached garage, pollutants can float in. Even when the door is closed, cracks in the joints and walls can let carcinogens and carbon monoxide leak indoors throughout the day. If you happen to have low indoor air pressure, your home can actually suck contaminants inside continuously. Combustion-related impurities...


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When looking for healthy flooring options, there are two major culprits to avoid: toxicity and dust. While this seems obvious, many flooring options will involve either or both. At Clarum, we believe your home should be comfortable, beautiful, easy to maintain and above all, healthy. Our approach to flooring reflects that. Toxic Floor, Dusty Floor According to Jeff Gearhart at SustainablePractice.org, the same toxic chemicals found in children’s toys “show up everywhere in home improvement products” including flooring, and have been linked to conditions including “asthma, birth defects,...


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What does insulation do? It maintains the living temperature you like best, of course! However, there’s more to it than that. What else does insulation accomplish? What are the passive design standards for insulation? And how does Clarum approach this? Allow us to give you a tour. What Insulation Does Insulation regulates temperature by preventing thermal bridging and unwanted air flow. Thermal bridging is when heat passes through solid objects, leaking in or out of your house. With a strong thermal resistance (R-value), insulation slows down the loss of heat. It also prevents drafts. Most...


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