Produce PassivHaus in ArchiCAD

Produce PassivHaus in ArchiCAD

Kaplan Thompson ArchitectsWith six projects featured on the recent NESEA Open House Tour, Portland, ME based Kaplan Thompson Architects (KTA) is fulfilling its mission to create and design buildings that are “Beautiful, Attainable, Sustainable”. We’ve chosen to highlight two of the projects KTA is designing, in light of the focus on sustainability this week’s Greenbuild show in Toronto provides. These two unique residential designs place high demands on ArchiCAD.

Harborview Townhouse

Harborview Townhouse

KTA is now in the early phases of permitting for a seven-unit condo project in Portland, ME (Harborview Townhouse) and is supervising the build on a very unique single family home in the mountain regions of Virginia. (Earthship Farmstead). Both are two unique projects designed to obtain LEED certification and Net Zero Energy use and Passive house Certification.

The internationally-recognized green building certification known as LEED, or Leadership in Energy and Environmental Design was first developed by the U.S. Green Building Council (USGBC) in March 2000. Building owners and operators can find through LEED a workable framework to identify and implement areas to apply green building design, construction, operations and maintenance solutions. Net-Zero Energy Buildings can be independent from an energy grid supply, whether harvested on-site through solar or wind energy. The building’s overall use of energy is reduced through efficient HVAC and Lighting technologies.

The Passive House concept represents today’s highest energy standard with the promise of slashing the heating energy consumption of buildings by an amazing 90%. In order for a home to achieve Passive House standards, it must be a very well-insulated, virtually air-tight building that is primarily heated by passive solar gain and by internal gains from people or electrical equipment from inside the building. Energy losses are minimized. Any remaining heat demand is provided by an extremely small source. Avoidance of heat gain through shading and window orientation also helps to limit any cooling load, which is similarly minimized. An energy recovery ventilator provides a constant, balanced fresh air supply.

Earthship Farmstead

LEED certification is commonly sought in sustainable architecture, where Passive House is not. Passive House requires extremely strict adherence to energy use, and LEED provides a focus on all elements of sustainability. “We realize that aiming for simultaneous LEED and Passive House certification is a significant undertaking, especially when you consider that only twelve homes built in the United States have managed to be Passive House certified,” explained Thompson. “A LEED silver certification can still have poor energy use.”

Though greatly varying in their design demands and end use, the successful process applied to each build can be attributed in part to ArchiCAD’s flexibility, according to KTA principal architect, Jesse Thompson.

“We’ve become proficient in using ArchiCAD to complete Net Zero, such as our high publicized Bright Built Barn. As we move forward and fine tune our process to achieve the even more rigorous Passive House standards, we are able to analyze the project and do it for less without hiring an outside firm. We’re making it work on projects that are 2,000 sq ft houses and it is still working. We’re making it accessible – because of our ability to use the software we’ve already been using. The high end projects give you the room to learn, but it is possible to use it in a targeted way to get going on smaller projects.”

Harborview Townhouse

The Harborview Townhouse project provides an example of how KTA has used ArchiCAD to design a multi-family dwelling. Thompson says the seven-unit condominium complex’s design is aimed at achieving a building that can be heated with the power equal to that used by a single hair dryer – in other words, extremely energy efficient. Going beyond LEED certification, KTA is working toward Passive House certification on the multi-family residence. That required an efficient design process as well.

Even though situated in a cold Northeastern climate, Harborview is built so efficiently that heating costs are estimated at $300 to $400 annually per unit. Thompson says the added efficiency didn’t add to the bottom line, “We’re able to put more efficient systems in, without it being more expensive to build. That is just not possible without the early on manipulation we can perform with ArchiCAD. Granted, it matters how the builder builds it, but we are confident in the model we’ve created and the quality standard we’ve called for.”

Harbor View is a large enough building to have a few hundred window units – an energy vulnerable element in any home or residence. KTA took advantage of ArchiCAD by creating a window schedule for each unit. Then the architects were able to pull all the windows out and enter them into the energy model. “What we used to do was run all the calculations after the design was done, but not be able to change the results. Now that we’ve modeled everything in full 3D we can analyze energy use at the same time the developer is analyzing cost,” explained Thompson,  “our work proceeded three times faster. As with many of our energy efficient projects – especially those we hope to achieve Passive House Certification we need to remove unnecessary steps and avoid surprises. Using ArchiCAD made our process more streamlined.”

With such a complex building, having the window schedule to plug into the design made it possible to modify window units and determine how those changes affect cost before committing to changes. “It changes the design perspective, from what can we afford to what is the best building we can create. ArchiCAD as a tool is helping us design better and smarter.”

KTA works from a list of every window in the building – inside ArchiCAD’s automatic scheduling, to better organize it. Windows can be swapped out or moved and not lost. When KTA’s developer wants to know how much it will cost he’s able to run the window schedules and see how the cost is affected on a unit by unit basis. Not only is it critical to the pricing, it has provided the developers with an affordable sales tool, adds Thompson. “Rendering 3D in ArchiCAD gives us the opportunity to demonstrate the condos complete with interior and exterior perspectives before they buy. The accurate floor plans have helped prospective buyers visualize the section and since we can pull these images off the construction documents it saves the developer from having to hire a separate sales person.”

Earthship Farmstead

Earthship Farmstead

Nestled into the hillside in a mountain region of Virginia, KTA is applying similar techniques from ArchiCAD and working toward achieving the strict Passive House certification for a farm house. The clients stated they wanted the home to be Net-zero energy (or energy positive!), Passivhaus and LEED certified. Having had previous experience with Net-Zero homes would serve KTA well on this project. “Earthship Farmstead was an entirely different project, born out of a client request to have a net zero home, off-grid, with sheep grazing on their roof,” explained Thompson.

KTA designed and is now overseeing the construction of the farmhouse so that it is built to the German PassivHaus standard. The complicated design includes a steel frame and concrete roof. The full steel frame was modeled in ArchiCAD, there are complex angles and miters and all the details were built inside ArchiCAD to demonstrate to everyone on the project how to get from concept to full final built project. Thompson says the use of ArchiCAD was critical to the success of the project.

Earthship Farmstead

“Since there’s so much weight on the top of the home, we had to design it around a steel frame. But in keeping with Passive House standards, we had to make sure that the steel – which conducts cold – never had an opportunity to compromise the airtight nature of the home. We have very high tech thermal breaks in the design – especially the shade patio – there are steel columns there that hold it up, but they cannot connect to anything inside because of the risk of cold conduction. Put simply, the only way to get this built was to design it in ArchiCAD.”

KTA situated the house directly in the hillside, taking care to adjust the floor plan so it would conform to the contours of the field. Working with the location, an eastward facing slope, the firm chose to extend the living and dining room areas out onto the crown of the hill – to better take advantage of winter sunshine for natural heating.

 

 

 

 

2 Comments

  1. Miss Mosc,

    This is a very interesting and crucial connection you make between LEED, Leadership in Energy and Environmental Design mainly utilizing digital-base research program, and ArchiCAD, a digital-base design program, in order to design a successful building. As the one who is highly interested in the impact or influence of digital technology on architecture, I am immediately intrigued by the design scheme with sustainability through LEED and aesthetics through ArchiCAD. In this post, you mentioned two great examples of “a seven-unit condo project in Portland” and “a unique single-family home in Virginia” that are designed to achieve LEED certification and Net Zero Energy use. This means that those two buildings are efficient and sustainable. It is great since there is energy lacking followed by the high-energy usage from old technological development. There has been a great effort to resolve the problem arisen from sustainable issue. Digital programs are the part of it. Now, it is impossible to think of architectural design process without encountering digital programs. Like the cases of LEED and ArchiCAD, when we think of efficiency, sustainability and even form and space of building, it is always necessary to use those computer programs. As a result of that, there have appeared more and more computer-base programs, such as rhino, grasshopper and revit, to give architects or designers more opportunities to create new, sustainable and artistic buildings. It seems like successful architecture or a building is always sustainable and aesthetic. Then, should we consider that it is failure of architecture when one fails in one of those categories? For instance, Frank Gehry attempts to design his buildings more artistically rather than sustainably. Can you consider him as an unsuccessful architect?

    While we are mostly focusing on digital elements for sustainability and designing process, one aspect that I am wary of is that if we are too dependent on digital elements. It is great to have accurate information and freedom to design buildings. However, according to Julio Bermudez and Kevin Klinger, as digital technological systems are developed, “extreme conceptual and spatial transformations have come about in relation to the introduction of mechanical reproduction, computer graphics and redundant systems.” Thus, even though digital development in architecture has distributed a number of great advantages to architects and society, it is not deniable that too much development or use can lose its original meaning and pupose. Do you believe that such digital technology has been developed too fast, and it is time to take it slow? Furthermore, do you think that as a result of major focus on digital development, old processes of physical experiment and models are being neglected? Overall I find the current well-developed digital systems intriguing. Thank you for sharing those architecturally successful examples sustainably and aesthetically.

    Reply
  2. anyone else heading to denver for the north american passive house conference sept 27 – 30? any graphisoft participants or showcasing of ac16?

    Reply

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