Wednesday, January 31, 2018

Low Carbon Land Use: Paris, Pittsburgh, and the IPCC: Post 5: The Land Use Stabilization Wedge: Buildings: A Series by John R. Nolon

This post is the fifth in a series that will appear over the coming months.  

Low Carbon Land Use: Paris, Pittsburgh, and the IPCC.  

The Land Use Stabilization Wedge: Buildings

by John R. Nolon Distinguished Professor of Law

Elisabeth Haub School of Law at Pace University

This blog begins a discussion of discrete strategies to mitigate climate change through land use regulation.  Its focus is buildings. In 2004, Princeton Professor Robert Socolow provided a framework for mitigating climate change through “stabilization wedges,” each capable of preventing at least a billion metric tons of carbon emissions annually using existing technology.   This and the next four blogs describe an alternative: the “land use stabilization wedge.”  Whether, in the aggregate, the existing land use techniques described below and in subsequent blogs will prevent a billion or more metric tons of emissions each year depends on how many, and to what extent, local governments embrace them.  See The Land Use Stabilization Wedge Strategy: Shifting Ground to Mitigate Climate Change.

According to the Census Bureau, the U.S. population will increase by over 90 million people during the next 40 years. Using today’s domestic household size, there will be around 34 million new households. Each will require a home and many of them will need workplaces. The 30% increase in population will expand significantly market demand for residential and commercial buildings, as will the need to substantially rehabilitate or replace millions of structures that will age-out during the next four decades.

The most recent EPA Greenhouse Gas Inventory estimates that residential and commercial buildings emit nearly 40% of domestic CO2, consume over 70% of the electricity produced in the U.S., and are responsible for over 40% of total energy used.  

State legislatures adopt energy conservation codes for buildings, which in many states are then adopted, enforced, and enhanced by municipal governments.  Similarly, the land use standards that dictate energy efficiency in new and substantially rehabilitated buildings are created by state and local governments. The size and shape of buildings and their interior spaces, their thermal efficiency, and whether they are served by efficient energy sources are dictated and influenced by zoning and other local land use regulations.  

In a previous blog, the novel idea of requiring large, energy consumptive houses to be more energy efficient was demonstrated by its incorporated into local law in Marin County, California. The County requires large homes under 4,000 sq. ft. to exceed energy conservation code requirements by 15%. If the home is over 4,000 sq. ft., but less than 5,500 sq. ft., it must exceed the state code in efficiency by 20%. For homes between 5,500 and 6,500 sq. ft., the requirement is 30%. Homes over 6,500 sq. ft. must be “net zero energy” users; a goal that green builders can actually achieve.

Energy Star is a voluntary set of standards, one of many that local governments may reference in their zoning and energy code requirements. The Town of Greenburgh, NY, enhanced its local energy code by requiring all new homes to comply with the Energy Star rating system promulgated by the Environmental Protection Agency and the U.S. Department of Energy. Energy Star can achieve energy savings in excess of 30% greater than the base energy code. It governs appliances, heating and cooling systems, the thermal envelope, electrical, ventilation, and equipment efficiency.

Also in New York, the Town of Blooming Grove offers home builders a density bonus under its zoning code to encourage them to adopt Energy Star. The Town awards a 10% increase in the number of homes that can be constructed under local zoning in exchange for making them all Energy Star compliant.

Local land use boards can require developers and their design consultants to follow an integrated design process, where they collaborate during the early stages of the project review process to achieve the greatest possible energy conservation and cost reduction. It is at this stage that decisions can be made about building orientation, form, shading, energy-efficient exterior lighting, window size and location, rooflines and extensions, reflective roofing, height-to-floor ratios, and building features that relate to passive ventilation and cooling.

Using similar powers and administrative techniques, localities can promote the construction of passive homes, both single- and multi-family. Instead of mechanized systems providing heating or cooling, passive buildings rely on the construction materials to use significantly less energy. For example, buildings utilizing the latest US passive house standards will only use 10-25% of the energy of a similarly sized building. Techniques used include thick insulation, exterior air sealing, fluid-applied silicone air barriers over plywood sheathing, triple-paned windows, and high efficiency heat-recovery ventilators.

In Milton, Vermont, a nonprofit developer created multi-family senior apartments, using passive building techniques.  The heating bill for these 30 senior households is expected to be 80% less that the cost of energy required by similarly sized buildings, and even less than what the owners of many single-family homes in the community pay for heat.

For more information on local land use strategies for conserving energy in buildings see  Land Use for Energy Conservation and Sustainable Development: A New Path Toward Climate Change Mitigation.

Material from this series will appear in Low Carbon Land Use: Paris, Pittsburgh, and the IPCC, an article to be published by the Arkansas Law Review.

Previous posts in this series are available here:

Post 1:  Paris, Pittsburgh, and the IPCC

Post 2:  Post-Paris Contagion

Post 3: Carbon Emissions: The Land Use Connection

Post 4:  Shaping Human Settlements

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