Urban Design Criteria for Zero-Carbon Neighborhoods

Improving the quality of life has always been considered as one of the human purposes. “creating and maintaining balance between natural and built environment” has a significant role in improving the quality of life. Before industrial revolution, man and nature always was in balance but after formation of industrial revolution this balance was faded and lost ,over the years. This imbalance, reached the highest level in the second half of the last century. During the second half of the last century, the world’s urban population has increased tremendously. Migration to cities has primarily occurred, and will continue to happen, in the so-called less developed countries as the result of increased economic and social opportunities offered in urban areas and the degradation of rural economies and societies. The extremely rapid urbanization has led to extremely serious environmental, social, political, economic, institutional, demographic and cultural problems. The tremendous increase in the world’s population and in urbanization is the main reason for the continuous increase of energy demand and consumption in most countries. Building sector and transportation sector are the major consumers of energy in many cities. To responding energy demand of these sectors, the use of fossil fuel is rising. One of the consequences of this rising, is increasing pollutant like greenhouse gases. Increase in greenhouse gas (GHG) emissions is leading to climate change. According to IPCC report in 2014, GHG emission is the major cause of climate change. Climate change brought about by man-made emissions of greenhouse gases has been identified as the greatest challenge facing human society at the beginning of the twenty first century. Climate change, it is predicted, may potentially damage every natural and human system on the planet. Today, climate change is became as one of the most important concerns of scientific and political circles, so It is clear that urgent action is needed and that the scale and scope of such action will be hugely varied. At present, the main worldwide response to the threat of climate change is mitigation; especially the lowering of greenhouse gas (GHG) emissions across a variety of scales. The preponderance of scientific evidence suggests that climate change is caused and exacerbated by anthropogenic greenhouse gas emissions and that lowering the amount of gas being emitted will limit climate change effects. An increasing amount of climate research now points to adaptation as a necessary means of addressing unavoidable climate change impacts. Adaptation to climate change refers to efforts to develop resilience to predicted or potential climate impacts and effects before and as they happen. In order to responding climate change- as the biggest crisis of this era- and achieving adaptation to climate change, proposing efforts and strategies in various disciplines is inevitable and unavoidable. Urban design and its strategies can have a key role to responding climate change impacts and achieve adaptation. But it is obvious that traditional urban design is not sufficient to responding this. A new paradigm is required to develop resilient cities that can adapt and thrive in changing global conditions, meet the requirements of carbon-reduction and other environmental measures, and sustain urban populations in more compact settings by providing amenities that people need and want. The scope and speed of current changes demands that urban designers define compelling visions and integrated design measures for shaping resilient cities. From energy and transportation to water and green infrastructure, urban designers can shape these systems to shrink our ecological footprint, configure resilient urban form and adapt our cities to climate change. A climate-resilient urban design strategy requires expanding traditional place-making urban design qualities to include principles of sustainable design such as resilience, comfort, resource efficiency, and biotic support. Today, resilience is one of the most important qualities that considered in urban design. There are various ways to achieve resiliency through urban design. Reducing CO2 emission is the most known and common way to achieve resiliency. In the past, efforts at reducing CO2 have focused primarily on building scale (low to zero-energy buildings). While there has been great progress in the energy efficient buildings over the past forty years, buildings alone do not include transportation and infrastructure systems (energy, water and waste) as part of the design process, so low-carbon urban design is considered as an inevitable necessity. Low-carbon urban design principles can be classified into sevencategories which are called as “seven rules of sustainable and low-carbon urban design”. These principles include: 1)restore streetcar city, 2)designing an interconnected street system, 3)locate commercial services, frequent transit, and school within a five-minute walk, 4)locate good jobs close to affordable homes, 5) provide a diversity of housing types, 6)create a linked system of natural areas and parks,7)invest in lighter, greener, cheaper, and smarter infrastructure. These principles represent the elements of a whole. Achieving one without the others – particularly if it is at the expense of the others – will be of limited value and could be counterproductive. Low-carbon urban design principles and strategies can be applied in different scales. Among the scales proposed for urban design, neighborhood is recognized as an appropriate scale for application of low to zero-carbon urban design strategies, because it aggregates all the systems and flows. It has the potential to integrate the design of transportation, buildings, infrastructures, landscape and land-use while engaging the design of public realm as part of the system. This article seeks to present the urban design criteria for low to zero-carbon neighborhood by exploring the studies and the best practices (in Freiburg, Hannover, Stockholm, Malmö and London) to create low to zero carbon neighborhoods. The result of the research is shown as urban design criteria which categorized by urban form and building typology, transportation and land-use, energy, landscape design and creativity. These criteria not only is in consistent with the low – carbon urban design principles, but also if these criteria are applied in an integrated way, we can expect creating a low to zero-carbon neighborhood; A neighborhood with qualities, such as local identity, inclusion, human scale, lower energy consumption, lower CO2 emissions and, most importantly, greater resilience.