Attainable Sustainable Design

Technical advice, case studies and additional resources for low-energy design

  • Software Review: Sefaira

    Amy Leedham
    Jul 11, '13 8:44 PM EST

    Almost 2 years ago, EHDD signed on as early adopters of Sefaira, a new energy modeling tool built specifically for architects to use in the early stages of the design process... also known as the holy grail. The team based in London and New York came to our office as part of a tour around the country to try to convince firms to buy into the program in exchange for an opportunity to provide feedback and input that would help develop the tool. I was skeptical at first, but after hearing the presentation and some very satisfactory answers to what I must admit was an onslaught of very specific and technical questions, EHDD signed on, and here's why. 

    There was some hesitation about the fact that Sefaira has built their own simulation engine. There are plenty of engines out there that are verified, like DOE-2, so why fix it if isn't broken? The short answer is that DOE-2 and other engines were built for very detailed, engineering based energy models, and the purpose of Sefaira was not necessarily to get the granularity  achieved by compliance models, but rather to get quick results that let you compare the general impact of different strategies. Furthermore, Sefaira minimizes the number of inputs required to get meaningful results which greatly increases the ability of the architect to use the software. 

    Overall, I find the balance between control and specificity and ease of use to be very well achieved with Sefaira. The interface allows one to rely on automatic "typical" inputs for things like control temperature and lighting power density, but also allows a more sophisticated user to fine tune and control these inputs as well. This level of transparency and control is what is missing from free tools like COMFEN, and can be important in specialized building typologies.

    At this point, I have not investigated the water tools very much, but the fact that they exist and are integrated into the program is great. This approach allows for a more holistic sustainable design, and the fact that building envelope, renewable resources, and water are all incorporated in one tool was very desirable. The software also creates highly graphic outputs which don't need any post processing to be legible, another rarity in the world of energy modeling. I still prefer to export the raw excel data and customize my own graphics, but the fact that it allows for both is also a huge step forward.

    Sefaira is continually upgrading itself and adding new features, which is another positive sign. The industry changes rapidly, and generally, they are able to respond and update the software in a timely manner. One such recent addition, is the capability to perform overheating analysis, which is critical in the UK for code compliance. While this is not usually an issue in the US, the ability to simulate comfort as well as energy use will only improve our buildings as we move forward. 

    One drawback is that at this point Sefaira is only compatible with Sketch-up. When the software was developed several years ago, sketch-up was the go-to tool for architects during conceptual design. Now that the industry is moving towards Revit, Sefaira is less applicable as a seamless introduction to the design process, but they are working to remedy that and I am sure they will release a Revit plug-in soon.

    For more information how Sefaira works you can visit their website.

    View full entry

    Intro To Sefaira

  • Solar Decathlon Europe: A Review of the Winners

    Amy Leedham
    Nov 8, '12 12:55 PM EST

    The European Solar Decathlon took place in Madrid in late September and included teams from around Europe as well as Brasil and China.  There are some really interesting designs that came out of the competition and given that Europe is usually quicker to adopt and implement sustainable... View full entry

  • Polystyrene Insulation: The Ugly Side of Flame Retardants

    Amy Leedham
    Oct 2, '12 2:17 PM EST

    Insulation is one of the main strategies being implemented to improve the energy efficiency of buildings around the world. However, this strategy is less affordable in the US because of the added cost of treating the insulation materials with flame retardants. Furthermore, the flame retardant... View full entry

  • Film Review: "Urbanized" by Gary Hustwit

    Amy Leedham
    Mar 15, '12 7:30 PM EST

    Last week I went to see Urbanized by Gary Hustwit which was being screened as part of the San Francisco Green Film Festival. Things got off to a pleasing note when the short animated film Second Hand by Isaac King was played as an opener for the evening. I loved the message and was... View full entry


  • Reducing Energy in 'Difficult' Typologies

    Amy Leedham
    Jan 30, '12 4:51 PM EST

    The recent article in Architectural Record about the respectable energy targets for the new Barnes Museum design by Tod Williams Billie Tsien Architects raises an issue that sparks further discussion. By now, the strategies for reducing energy use in offices and residential projects are mostly... View full entry

  • Biophilic Design

    Amy Leedham
    Jan 19, '12 6:04 PM EST

    While reducing the energy use of buildings is essential for a sustainable future, it is equally important to improve the conditions in which humans live, work, play, heal etc.. The benefits of natural daylight and ventilation have been proven to improve productivity and reduce sick days in office... View full entry

  • Energy Modeling Software De-Coded

    Amy Leedham
    Nov 3, '11 5:41 PM EST

    Note: This post was supposed to be rolled out on Halloween... in tribute to it being a very scary subject that causes controversy all across the architecture, construction and building performance industries. Despite this controversy I wanted to provide a general overview of the topic and a guide... View full entry

  • Beyond LEED and BREAM: The Living Building Challenge – Part 1

    Amy Leedham
    Oct 12, '11 3:03 PM EST

    With several articles about the new Net-Zero Bullit Center in Seatle in the press NYTimes, (Citytank,  and the NYTimes again to name a few) It seems a good time to shed some light on the Living Building Challenge. The Bullit Center is aiming for Living building certification and is the first... View full entry

  • Shipping Container Houses: The Full Story

    Amy Leedham
    Oct 11, '11 11:31 AM EST

      Shipping container architecture is fast becoming the hot new green trend for both designers and DIY’ers who want their own sustainable, chic home. My brother and his wife have asked me to design them a shipping container home and despite my familiarity with the topic I was pretty... View full entry

  • What IS Sustainable Design? Part 1

    Amy Leedham
    Oct 10, '11 11:48 AM EST

    The word sustainable gets thrown around a lot these days and most people don’t really now what it means. I have put ‘part 1′ in the title because I believe that sustainable design is a continually evolving concept and it is difficult to define it in a few hundred words... View full entry

  • Case Study 01: Liquid Desiccant Waterfall, UMD 2007 Solar Decathlon Team

    Amy Leedham
    Oct 7, '11 5:59 PM EST

    The 2007 University of Maryland LEAFhouse placed second on the international Solar Decathlon competition, but the innovative interpretation of an environmental technology that resulted in the desiccant waterfall is a perfect example of the possibilities of integrated design. (The Solar Decathlon... View full entry

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A discussion on everything to do with sustainable design. From renewable energy to implementing integrated design in professional practice. Case studies, article reviews and green building certification methods and additional resources will all be included.

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