«CSAAR (7: 2010: Amman) Sustainable Architecture and Urban Development \ Edited by Steffen Lehmann, Husam Al Waer, Jamal AI-Qawasmi. Amman: The Center ...»
1 Introduction In thinking about the current condition of sustainable housing in America, it is important to differentiate between dense, metropolitan America and the more spacious rural America. In contrast to Europe, the United States has an enormous surplus of land, a condition which greatly affects American city and regional planning. This makes possible the American Dream: owning a single-family house on a site that i8 spatially independent of both its neighbors and urban density. These free-standing houses are typically located far from city centers, realized without considerations of sustainable concepts and, therefore require large amounts of energy - both to construct and operate.
The research currently underway focuses on the design and detailing of an affordable Zero Energy House that implements and demonstrates passive and active sustainable strategies. In addition research i8 also targeting appropriate specification of materials and methods for the purpose of sustainable optimization and building construction efficiency. Through a process of collaboration the assembled multidisciplinary design research team examines all design and building models/options to determine and therefore proof the impact on the buiIdings energy consumption, material performance and cost effectiveness. This cooperative design process allows for informed and intelligent design decisions to be made based on academic research with "real world" applications.
2 Energy Consumption
According to the World Factbook, the US is, with 3,892,000,000,000 kWh, the leading country in energy consumption, followed by China (3,271 Mio. kWh) and the European Union (2,926 Mio. kWh) (Central InteJligence Agency, 2009). US energy consumption has been broken down as folIows: 29% Transportation (Vehicles which transport people/goods on ground, air or water), 21% lndustrial (Facilities and equipment used for producing and processing goods), 11% Residential (Living quarters for private households) and Commercial (Service providing facilities and equipment [businesses, govemment and other institutions ]) and 41 % Electric Power (Energy Information Administration, 2007).
According to the USGBC, in the United States alone, buildings account for:
72% of electricity consumption, 39% of energy use, 38% of all carbon dioxide (C0 2) emissions, 40% of raw materials use, 30% of waste output and 14% of potable water consumption.
Looking at residential construction specifically, energy use can be broken down as folIows: 37% for space heating, 15% for water heating, 14% for lighting, 13% tor air conditioning, 6% for refrigeration, 6% for electronics and 6% for wet cleaning.
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3 Energy Costs
According to the US Government Energy Information Administration,
residential energy costs are expected to increase in the next 25 years as folIows:
fuel oil 72%, petroleum 74.4%, electricity 15% and natural gas 14.4%. (Energy Information Administration, 2009) In comparison, the BMWi monitored the development of energy prices in Germany throughout the years 1998 and 2007: space and water heating +38%, process heat +56%, lighting 42% and fuels +38%. (BMWi, 2008).
The increasing worldwide demand for fossil fuels without any growth in the supply of these resources has already begun to have serious economic consequences. As resources become scarce, fuel prices will become prohibitively high over the next generation, making our current way of life unaffordable for the average person. In light of these concerns, there is a growing need to improve building efficiency and minimize the energy demand of heating/cooling, lighting and water heating systems.
Investigation into alternative energies is indispensable if we are to reduce our dependency on fossil fuels and avoid an inevitable societal disaster. With oil at $132-r a barrel, tougher building codes and concern about the nation's dependency on foreign oil, there is a renewed interest in energy efficiency that has not been seen in almost a quarter century (William F. Becker Jr., 2008); a movement towards energy-efficient buildings is clearly gaining momentum.
History has shown that the more energy costs increase, the more the industry feels the need to develop innovative and alternative concepts and, in turn, the more the consumer is willing to change their personal attitudes. In addition to the need for individuals to change their underlying view of energy as an endless resource, architects should feel a responsibility when designing their buildings to reduce daily energy consumption.
4 Sustainable Development Due to various political and economic factors, Europe has outpaced the US in the development of sustainable architecture - therefore, it seems prudent to take a closer look at their sustainable concepts. Most ofthese strategies are community based solutions focusing on a higher urban or suburban density, in order to lower the development costs and (in the densest case of town houses) even the heat losses, in addition to sharing block heating power plants and solar devices. All of them implement passive building strategies: paying attention to orientation, shading and water coilection. Due to the density of these communities, people live mostly independent from their vehicles; there is a special focus on walkways and bike paths.
By simply copying the European concepts, it seems plausible and relatively easy to apply proven principles of sustainability to urban regions. However, most of the US inhabitants do not live in urban density, according to the European Ulrike Heine standard (City Mayors, 2007). America fills all top 12 1eading positions in the land area of the city, but Ameriea's densest city is Los Angeles has only 2,750 inhabitants per sqkm (rank 90), followed by San Francisco (rank 104) and New York (rank I 14). Due to the abundanee of spaee on the continent, the US follows a totally different spatial concept: in numbers: there are 128,203,000 households in the US, 80,406,000 (62.7%) of them are detached (US Census Bureau, 2008).
An average household consists of 2.62 inhabitants with a size of 2,349 sqft and
5.6 rooms per house.
There is a need for sustainable design that serves the average single-family house which fits into the urban, suburban and rural context.
5 Building Costs
With the recent political changes, the topie of sustainability has gained popularity. Homeowners and construction clients are becoming interested in low and zero energy building design. The first low energy houses have been built.
However, all ofthe realized examples seem to be high cost buildings with major technological installations to aecommodate the comfort level ofthe client.
There is an obvious lack of simple and affordable houses that follow the rules of sustainability in the sense of climate sensitive design; a product that is marketable and ready to compete in both function and priee with the eurrent level horne eonstruetion.
6 Project Description The larger scope ofthis projeet is to design, detail, simulate and evaluate a Zero Energy House, which can be adapted to the climatic conditions of Southem American States using passive energy strategies and natural materials. The House will meet the highest standards of contemporary design. The planned building should be a prototype of sustainable architecture - a show-house for students, faculty, researehers and clients - making sustainable, ecologieal, energy efficient and climate sensitive architecture experiential, touchable and measurable. The goal of the research is to lay the design foundations for the later physieal realization of the Zero Energy House as a showcase for the University, for The Southem American Sates and for American Architecture. The outcomes of the research include a novel digital simulation (i.e. movie) demonstrating the process of realizing the House (from faetory to building site to use) and a numerical evaluation of this digital simulation for energy consumption, thermal behavior and other performance parameters.
This research involves designing and detailing an affordable low energy house (Zero Energy House) adjusted to the climatic conditions of upstate South Sustainable Architecture and Urban Development 217 Carolina and implements passive and active sustainable strategies and natural materials, with the ultimate goal of constructing a physical prototype and evaluating i1. We are currently conducting a theoretical digression on a meta level to a smalI, realizable unit, adjusted to the specific situation of South Carolina. We are not only developing the standard design documentation for the project, but generating a novel, digital simulation (i.e. a movie) of the process of its realization, from factory to building site to use by inhabitations. This simulation serves as a model for tracking and evaluating energy consumption and other parameters ofthe construction and use ofthe building.
The key requirements of the house are achieving a comfortable indoor climate with a low level of occupantJsystems interface (i.e. low energy and low maintenance costs) and the use ofnatural, regional, recyclable materials. Maxims like compactness, orientation, passive ventilation, passive cooling, passive lighting and passive solar energy gain will be applied in conjunction with more technical innovations such as active storage masses, an autonomous water circulation system, the pre-conditioning of water and solar installations for domestic energy gain. Every installation is supposed to be testable and provable.
All other known competitors have not yet worked with an approach of reducing in principle the energy consumption by taking advantage of passive design strategies in combination with low technology energy gain (Robert Gonzalo, Kar! Habermann, 2006).
8 Educational Approach
The research is being conducted as a Creative Inquiry course, which will span four semesters. Two graduate students and six undergraduates from the schools of Architecture, Civil Engineering and Materials Science are currently working together to gather key information on sustainable practices, discuss technical considerations and conduct building performance simulations. This collaboration across disciplines not only brings a breadth of knowledge to the discussion at hand but is also an invaluable experience for the students as they prepare for their professional careers.
At the beginning of the project, four teams of two students were each assigned a specific geometric volume (square, rectangle, L-shape, etc.) equal in total square footage and height. Using Design Builder simulation software, the teams began energy use studies on each form, noting the effects of altering building orientation, roof form, window and door openings and shading devices.
After identifYing the most efficient configuration for each form, this knowledge was then be used as framework for further development of the specific building designs. Every single step of the design, either in floor plan development or fas;ade design was simulated and evaluated and therefore proven due to its impact on the building's performance. In the foIIowing steps the simulations will be expanded to compare the performance of different building materials and also to implement various active and passive strategies for controlling indoor comfort. By the end of this two-year investigation, the Zero Energy House Ulrike Heine project will produce several detailed and realizable strategies for affordable, sustainable residential design.
9 Passive Strategies At the current stage of the research all low cost passive strategies are in the process of analysis due to their impact on the low energy performance of the Zero Energy House. The strategies dcscribed below became part of the design process and were simulated in a second step on one single building form, which was chosen to be the showcase for our specific project.
Figure I: Floor Plans, bottom (left) and top (right) illustrating the functional center core and the c1ear north/ south orientation and the adjacent porches ofthe building.