Date Occurred: 13 0830? Responded to the MN PUC's request for comment on the proposed application of the Minnesota's solar incentive program. Advocated for utility participation in solar incentives, rebates and net-metering energy payments in return for privilege to operate a utility monopoly at the discretion of Minnesota residents. Supported distibuted power to decrease wasted energy due to transmission losses, smart / microgrids for electrical system resilience and environmental sustainability.
With building heating and cooling energy needs reduced up to 90%, your building is Low-Energy with a small energy bill. When adding renewable energy, your building is in a much closer position to becoming Zero-Energy, creating enough energy to cover all building needs, or Net-Energy, creating more energy than your building needs. Net-Energy buildings are “regenerative”, improving our planets health, by reducing our need for carbon fuel consumption to meet other energy needs like powering electric or hybrid vehicles. Solar electric (photovoltaic) and solar thermal (solar water and air heating) systems can be sized to generate clean, green renewable energy to meet building energy needs. On-site photovoltaic is the most energy-efficient because it minimizes utility line transmission losses. "Solar Gardens" or "Solar Farms" are great investments for homes that have enough solar access for Passive House to work, but not enough for cost effective photovoltaic which can be hampered by shading. Solar thermal is always onsite to minimize energy losses and is typically smaller so it may be easier to find a spot with good solar access. Solar thermal is more forgiving of intermittent shading. Wind energy works very well at the utility level where you see the large wind turbines in wind farms, but “Small Wind” can be typically less cost-effective. There are some areas that see significant steady breezes, but often not in urban areas. Most cost-effective "Small Wind" installations have towers that are 75-200 feet and taller.
Anderson Sustainable Architecture designs very energy efficient buildings where natural solar energy and active photovoltaic and thermal panels can work together in a system to efficiently and effectively meet building operating energy needs while providing a beautiful architectural expression.
Anderson Sustainable Architecture can help you review your site or potential site for Passive House, photovoltaic and solar thermal access.
REMEMBER: "You don't need to burn gas to power something that doesn't move" © Anderson Sustainable Architecture, Inc.
In Passive House construction, typical construction materials and components are used with the location, quantity of material and quality of installation being the larger construction changes.
• Insulation thicknesses are provided based on the climate. You wear a parka in cold winters when you wouldn't want a light spring jacket. Insulation properties vary and it is critical put the right material in the right place. Insulation can be one of the least expensive, highest financial returning and least CO2 producing energy saving investment you can make.
• A great Air, Vapor and Weather Barrier improvement has been placing barrier membranes where they are not penetrated by building trades. Where membranes absolutely have to be penetrated, such as at building electric and water service, the joints are taped and sealed. Six quarts of water can enter building cavities through a one square inch opening, and thats not a big opening when you consider the area of walls and roofs and the number of outlets, etc... that typically get poked through barriers. Keeping vapor membranes warm to avoid condensation has been another great building durabilty advancement. If a vapor barrier is below dewpoint any water vapor will condense on it before it permeates it. This condensation can lead to mold and construction damage.
• Passive House quality windows and doors are typically triple-pane with warm edge glass spacers and high-performance insulating frames. Based on area, a lot more energy is lost through windows and doors than walls. Glazed windows and doors make up for this by allowing light and heat energy to enter the house and then keeping the heat in. In summer, they keep the house cooler than traditional units. You can stand next to a Passive House window when it is 20 below outside and be comfortable. This adds usable comfortable space to your building. Passive House quality windows and doors are an investment, but the rewards are energy savings and building comfort. You really appreciate the quality of these advanced units when you open and close them. They have a smooth, solid feel that hasn't been experienced in America until now. Passive House quality windows and doors have been made and used in Europe for decades, but American and Canadian manufacturers are making inroads into the market.
• Energy-efficient energy recovery ventilators, appliances, lighting and building controls decrease building electric loads and their waste heat and moisture. Heat Recovery Ventilators were invented in the 50's, have minimal working parts and have provided steady service. Energy Recovery Ventilators are similar to Heat Recovery Ventilators, but they also repurpose moisture in the air, which is important in hot-humid climates like Midwestern summers. Equipment advancements are continuing to increase savings.
• The design of foundations is very important in Passive House quality buildings. Concrete foundations are a source of heat loss and water vapor intrusion in buildings. Concrete materials naturally wick heat and moisture. The earth around building foundations is typically 50-55 degrees and 98% humidity year round, except for the top 3-5 feet frozen in winter. Buildings maintain interior air temperatures of 68-72 degrees and humidity levels of 20-50%. Given that heat and moisture move from high to low concentrations, there is a constant wicking of heat and moisture through concrete footings and foundations and heat through slabs with only a vapor retarder separating them from soils. This is why basements are cool and humid enough for mold growth even with a dehumidifier running 24/7/365. You can't possibly dry out or warm up the mass of the earth to stop or slow transport. Passive House design minimizes the vapor drive by adding a vapor barrier or waterproofing at footings and foundations and keeping the vapor barrier below slabs as seen in standard construction. Taped joints are added to make the slab membrane continuous with the footing and foundation membrane. Passive House designs decrease concrete heat loss by adding load bearing insulation around and below footings, foundations and slabs on grade. The loading bearing insulation installed won't compress because it is selected to withstand the loads of the building. Similar loading bearing insulations have been used below bridge abutments and commercial aircraft runways for a long time where the insualtion is subject to far greater loads and repetitive impact.
During the gas crisis in the late 70's and 80's, with its long lines of cars at gas pumps, building scientists were looking for ways to save energy. "Passive House" was coined to describe their solution; houses that were passively heated by the sun to reduce their need to burn fuel oil and gas. They described their buildings as "super-insulated"; they were oriented east-west to maximize solar exposure; had windows located primarily on south walls with some windows on the east and west walls and few on the north; and they were provided with heat recovery ventilators that had been invented in the 50's. The homes had significant energy savings and approximately 40,000 were built in Midwest and Canadian cold-climate areas. When gas prices dropped the solution was mostly forgotten about in North America. In the 90's Europe was experiencing high fuel prices and building scientists there looked around the world for a solution. German scientists discovered "Passive House" and began implementing, advancing and testing it for their milder European climate. These scientists at the Passivhaus Institut (Passive House or Passive Building Institute in German) designed computer models to predict building performance, built test houses with sensors throughout the walls, roofs, etc... and measured the results. They advanced the design, advanced the computer modeling, built new test homes and measured the results. Repeat... Repeat... They ended up with the PassivHaus protocol that decades later has been followed and built throughout the world. In 2003 PassivHaus came back to the Midwest and the current American Passive House movement began. PassivHaus is now becoming the basis for energy codes in some European countires. Passive House can actually be a misnomer because the design protocol is applicable to any building type, residential, commercial, institutional, industrial, etc... for both new and existing buildings. Remodeling existing buildings for a significant energy use reduction is known as retrofit or deep energy retrofit.
Building owners, real estate, insurance and lending industry stake holders are increasingly recognizing that Passive House quality construction increases a properties value and protects that value. This information is being increasingly reflected in real estate appraisals, listings, and pre- sale building inspections. Market recognition of higher Passive House real estate value, along with the value of social cache, is strengthening a building owners opportunity for return on energy saving investments.
The quality reviews provided in the Passive House PHIUS+ Certification process is game changing in the building design and construction industry. The Process: • During the design and drawing development process, the Architect/Passive House designer forwards the project design and energy modeling to Passive House International | US (PHIUS), which acts as a third-party design reviewer contracted to the Owner. PHIUS reviews and participates in a rigorous review feedback process with the Architect/Passive House designer. When quality standards are met, PHIUS provides design pre-certification. Pre-Certification means that when the building is built as designed, it should meet the Passive House Certification requirements. • PHIUS provides Passive House rater training for construction industry-trained Home Energy Rater System (HERS) building raters, allowing them to rate Passive House projects as PHIUS+ Raters. The PHIUS+ Rater becomes familiar with the design and construction drawings and observes construction at key times. The PHIUS+ Rater notes if the Builder is following the design and appears to be meeting construction quality goals. The PHIUS+ Rater also provides field testing at key times; including blower door tests to confirm the building is well sealed; and smoke pen tests to locate any leaks so the Builder can seal any leaks before they are covered up in construction. As construction is completed, the PHIUS+ Rater provides a final blower door test and confirms the HVAC equipment and ventilation system through the building is functioning correctly and accurately adjusted. The contractor is still the one responsible for following the construction documents and providing their construction value to the owner, but with third party PHIUS+ Rater construction observation, the owner has an additional check on quality. (Note: As part of their contract with the owner, the Architect/Passive House designer does their own construction observations and reports to the owner. This quality review is missing when working only with a builder). When the PHIUS+ Certification requirements are met, the PHIUS+ Rater forwards their report to PHIUS. • PHIUS reviews the PHIUS+ Rater report for the owner, confirms requirements are met, and then issues the PHIUS+ Passive House Certification to the owner. With this process the building owner gains third party quality reviews, during both the design and construction phases, improving the quality and value of the building.
The benefits of Passive House quality buildings are: • Supreme Indoor Air Quaility and • Healthier Occupants. With a steady supply of fresh air, constantly filtered from exterior and interior air contaminants, and air temperature and humidity levels that avoid condensation and mold the air is cleaner, fresher and occupants healthier. • Increased Comfort. With draft free, consistent interior temperature and humidity building occupants will be comfortable, even next to a window with sub-zero outside temperatures. • Energy Savings. Up to 90% of needed building heating energy can be captured and repurposed from the passive heating of the sun and building occupants. • Decreased Building Maintenance and • Increased Building Durabilty. Building science informed design and construction manage temperature and moisture in building materials and assemblies, prolonging their life and decreasing necessary maintenance. • Power Outage Resilience. Highly insulated Passive House quality buildings can take 3 days to cool to 50 degrees inside during a winter power outage when the outside temperature is below freezing. Similarily, buildings take longer to heat up during a summer power outage. • Low, Zero or Net-Energy opportunity. Using significantly less energy, a Passive House quality building is the shortest step for renewable energy sources to cover most, all or more energy than a building needs. Unused energy could be sold back to an electric utility, power a vehicle or mow the yard. • Sustainable Design. Besides using less energy, and the building already meeting the goals of the Architecture 2030 Challenge, renewable materials such as lower-cost low-carbon insulation like cellulose can be used. • Financial Return on Investment. As the energy market fluctuates and rises, real estate energy saving investments gain in value.
Like a car, all the parts of a building have to work together to function. A building doesn't move, but energy and moisture move through a building 24/7/365. From the outside, energy forces in the form of solar radiation, freezing and frying temperatures, wind, snow, rain, humidity and on the inside; energy and moisture released by heating and cooling systems, lighting, cooking, laundry, bathing, computers, entertainment systems and the people living and working in the buildings; either drive heat and mositure through everything or are blocked and then sometimes released. In the past everything was extremely inefficient and leaked. Buildings were drafty and had huge energy bills. Adding insulation and later sealing buildings up were steps in the right direction, but the building wasn't seen in the context described above. The indoor air moisture wasn't managed, but as important, new building sealing layers were applied where they would get cold enough to cause condensation. How energy and moisture effect buildings and their components is building science. Passive House design principles were developed to manage the heat and moisture energy forces moving through a building in a healthy and energy efficient way. In solving the energy loss and moisture transfer problems in context, Passive House developed a holistic building design system, a comprehensive protocol known as the Principles of Passive House. See more in the Passive House History blog entry.
The Principles of Passive House are: • Provide a Continuous Insulated Envelope. Create an efficient and effective building design shape with insulation thicknesses appropriate for the climate to minimize building envelope losses and gains. Develop construction detailing that is thermal-bridge-free to eliminate condensation in buildings and inside building assemblies. • Provide a Tightly Air-Sealed Building Envelope to prevent outside air infiltration and conditioned air loss. • Provide High Performance Windows & Doors. Provide modest window areas placed with optimal solar orientation to create moderate solar gains. Avoid overheating in summer or on sunny exposures with exterior window shading. • Provide a Mechanical Heat and Moisture Recovery System with balanced ventilation and a filtered constant fresh air supply. • Manage Internal Building Loads. Provide energy efficient mechanical ventilation system, appliances, lighting and plumbing fixtures to minimize interior heat and humidity gains. • Provide a Renewable Energy System. After building loads have been minimized, provide renewable energy, now optimally sized, on site to cover remaining building loads.
Mark Anderson, AIA, CPHC
For my day job, I'm an architect focused on green design. Not a bad gig! Caring for the planet is a theme throughout my life. This page is where I like to talk about how that love for the earth plays out – in architecture and in my life.