Do Strict Land Use Regulations Make Metropolitan Areas More Segregated by Income?

Problem, research strategy, and findings: Income segregation has risen in each of the last four decades in U.S. metropolitan areas, which can have lifelong impacts on the health, economic productivity, and behaviors of residents. Although it is widely assumed that local land use regulations—such as minimum lot sizes and growth controls—exclude low-income households from wealthier neighborhoods, the empirical research is surprisingly limited. We examine the relationship between land use regulation and segregation by income using new measures for the 95 biggest cities in the United States. We find that density restrictions are associated with the segregation of the wealthy and middle income, but not the poor. We also find that more local pressure to regulate land use is linked to higher rates of income segregation, but that more state control is connected to lower-income segregation.

Takeaway for practice: Density restrictions do drive urban income segregation of the rich, not the poor, but should be addressed because rich enclaves create significant metropolitan problems. Planners at the local level need assistance from regional and state efforts to ameliorate income segregation. Inclusionary housing requirements have a greater potential to reduce income segregation than bringing higher-income households into lower-income parts of the city. Finally, comprehensive and consistent data on the impacts of local land use regulations should be collected to inform future research and planning practice.     

Regulatory Practices of Urban Agriculture: A Connection to Planning and Policy

Problem, research strategy, and findings: Municipalities across the United States are gradually recognizing urban agriculture as an integral part of planning, land use, and zoning ordinances. We review the literature on the regulation of urban agriculture at a moment when policy and regulatory vacuums exist and the acceptance and integration of urban agriculture is uneven. We review the current regulatory practices of 40 metropolitan and 40 micropolitan municipalities in the 4 U.S. Census regions. We find that municipalities are filling policy vacuums by adopting enabling ordinances (zoning ordinances, land use designations, resolutions), regulations on urban agriculture production (backyard animals, built structures, practitioner responsibility), and fiscal policy instruments (restrictions on sales of agricultural products, tax abatement, urban agriculture fees). Our findings support local planning practitioners in filling regulatory gaps, practitioners of urban agriculture in seeking how it’s done elsewhere, and researchers in discerning new applied and basic research projects. We identify 3 principal knowledge gaps: Planners need a complete typology of regulatory possibilities; a better understanding of how local, state, and federal legislations constrain or enable urban agriculture; and empirical evidence of the economic, social, and environmental impacts of urban agriculture.

Takeaway for practice: Planners should assess existing urban agricultural practices and consider which regulatory frameworks best support multiple local goals, incorporating a concern with urban agriculture into ongoing activities, deploying existing or innovative land use tools, facilitating institutional cooperation, and promoting inclusive decision making and community engagement.     

Planning for Unplanned Pork

Problem, research strategy, and findings: To understand how communities use zoning ordinances to achieve sustainability goals, we identify nine sustainability principles and 53 associated regulatory items that might be included in a zoning ordinance to achieve sustainable development and then examine the zoning ordinances of 32 randomly selected communities to determine if they included these principles and their associated items. We find both wide variation and some consistency in how zoning ordinances address sustainability goals, independent of city size or location in the country. Some of the identified principles and regulatory items are found in many ordinances; others appear in only a few. However, there is an inverse relationship between the age of the ordinance and the extent to which it includes sustainability principles. As ordinances are updated, it is likely that they will address more topical sustainability concerns. We study only ordinance content, not implementation; moreover, sustainability can be achieved in ways other than zoning. However, zoning ordinances that directly address sustainability in many dimensions are more likely to achieve these goals. We conclude that planners can more effectively use zoning ordinances to achieve sustainable development.

Takeaway for practice: This review of zoning ordinances can alert local planners to the many ways in which zoning ordinances could be used to achieve sustainability goals and suggest how planners can assess the contribution of their zoning ordinance to the sustainable development of their communities.     

城市房屋拆迁中的土地使用权问题探析

随着“私人财产不受侵犯”宪法保护程度的增强以及土地有偿使用制度的进一步明确,我国的城市房屋拆迁制度面临严峻考验。本文分析和研究城市房屋拆迁过程中土地使用权收回的正当性、土地使用权变更程序的合法性以及土地使用权补偿的合理性问题,并提出解决这一连锁问题的有效对策,为进一步规范我国城市建设提供理论借鉴和制度参考。     

Housing Diversity and Affordability: The Effects of 35 Years of Exclusionary Land Use Regulations on Housing Affordability in Adelaide,South Australia

ABSTRACT

Australia is often described as being in the midst of a housing affordability crisis. This research analyses the effect exclusionary land use regulations have had on housing diversity and affordability in Adelaide, South Australia. The research shows there are significantly greater numbers of relatively affordable dwellings available areas where an absence of land use regulations for significant periods of time has enabled housing diversity. It also shows that metrics that compare median incomes with median prices are unreliable indicators of affordability as median prices alone are unable to capture the breadth of housing prices that exist within them.     

Changing Residential Land Use Regulations to Address High Housing Prices

Problem, research strategy, and findings: In the past 3 decades, a series of presidential administrations—and the APA—have recommended that cities update their zoning codes to enable more affordable and market-rate housing development. I identify 5 main categories of policy recommendations they have suggested and then assess Los Angeles’s (CA) zoning changes in these categories between 2000 and 2016. I answer 2 questions: First, what zoning changes did Los Angeles adopt to address housing affordability? Second, how were these changes initiated, and what were their scope and geographic extent? I find that Los Angeles made modest progress in the 5 policy categories. The city left its large-lot, single-family zoning mostly untouched, but it rezoned roughly 1,200 acres citywide to allow at least 50 housing units per acre, reduced parking requirements in some areas, made it easier to build accessory dwelling units, and adopted new incentives for affordable housing. Several policy changes resulted from new state laws, and Los Angeles voters approved new incentives for affordable housing near transit. Homeowner influence likely prevented the municipality from engaging in larger zoning reforms. I do not study the effects of Los Angeles’s regulatory changes on housing production and prices, but such research is an important next step. I also do not assess new regulations that counteracted the impact of the 5 categories of policy recommendations.

Takeaway for practice: This research suggests 2 lessons: 1) Planners should encourage state governments to preempt local zoning when it reduces affordable housing options and there is limited local political will for change, and 2) planners should identify feasible and effective zoning changes that would increase affordable housing given local considerations.     

建立低碳城市规划实施手段:从城市热岛效应模型分解控规指标

通过分析城市热岛效应与城市规划研究的关系,提出了在绿色建筑和低碳城市设计要求中控制城市热岛效应的重要性,以及面临的规划管理操作问题.然后建立城市规划方案热岛效应预测模型,从城市规划的操作应用角度提出热岛效应的控制指标,并分析规划设计可以影响的控制因素,以指导城市控规编制规范.同时,以北京地区某低碳社区详细规划项目为实例,量化评价了规划方案的热岛效应指标,以及与热岛相关的控规地块指标对降低热岛效应的贡献度.最终将减缓热岛效应的目标,分解为法定城市规划管理体制内的发展控制手段.     

城市地下商业用地使用权价值评估研究

近年来,我国城市地下商业空间大量涌现,地下商业区成为市民休闲娱乐的场所。在地下商业用地租赁交易频繁发生的同时,国内关于地下商业用地使用权价值评估方面的研究却比较少见,这使得地下商业用地使用权价值评估实践没有相应成熟的理论和方法作为支撑。本文以南京市地下商业用地为研究对象,将基准地价的概念扩展到地下土地,试图建立地下商业用地基准地价与地表商业用地基准地价之间的关系。由此,本文通过一定的方法,确立了地下商业用地基准地价的近似推算公式。本文中演示的方法对于今后地下商业用地使用权价值评估理论的研究具有开拓性、启发性意义,也对现实中的地下商业用地使用权价值评估具有指导意义。     

城市地下空间使用权价格评估探讨

城市地下空间开发中在将土地利用由二维平面转为三维立体的同时,也将地价评估研究的客体扩大至地下,亟需客观地显化地下空间土地使用权价格。地下空间使用权价格的科学评估直接影响地下空间的开发利用,尤其是对地下空间商业开发主体的意愿影响较大;同时,价格杠杆也是政府对城市地下空间利用进行控制引导的重要手段。笔者对国内外研究现状进行了评述,提出了地下空间土地使用权地价内涵及评估方法选择,对我国地下空间使用权评估有一定借鉴作用和参考价值。     

基于控制性详规建筑限高的居住用水量预测方法探讨

通过对南京地区不同建筑限高的住宅项目进行用水量分析,研究了居住用地用水量与建筑限高之间的相关性,提出以建筑限高为标准分类选取居住用地用水量指标,以控制性详规中土地利用信息为基础对居住用地进行用水量预测的方法,提高了用水量预测在空间分布上的准确性,为用水量预测方法的研究开拓了新思路。     

从上海陆家嘴到重庆东部新城--一种可操作的以公共交通为导向的土地利用形态的探索

在实现城市可持续发展的总体目标之下,大力发展城市公共交通,并建立与公共交通发展相适应的城市土地利用形态已成为城市规划的一种共识,然而,鉴于我国目前城市开发建设实际操作中的具体步骤程序及困难,客观上又使得这一共识难以得到实际体现。如何结合我国的具体状况,使以公共交通为导向的土地利用开发在我国的城市建设过程中,尤其是新城区的建设开发过程中得到真正运用已成为一个亟待解决的问题。通过对我国城市土地利用开发普遍模式的分析并结合上海陆家嘴新区及重庆东部新城规划设计方案的对比研究,在建立可操作的公交导向的城市形态方面作出了有益的探索。     

Repealing minimum parking requirements in Buffalo: new directions for land use and development

Minimum parking requirements, which mandate off-street parking and have been a staple of American zoning codes for more than 80 years, are slowly falling out of favor due to incompatibility with sustainable urbanism, equity, and social responsibility. A new zoning ordinance in Buffalo, New York completely removes minimum parking requirements citywide, relieving developers and property owners from the mandate to provide off-street parking. This article performs a comparative analysis of guidelines in the zoning code before and after reform and examines the public engagement process that produced the change in parking control. Strong support for and little opposition to this zoning change suggest less resistance than anticipated to policies that formalize a reduction in off-street parking facilities. Findings suggest that removing minimum parking requirements is easiest where off-street parking requirements are least needed, and that the planning team in Buffalo proposed a bold idea after it detected, from special interest groups and the public, initial support for removing parking requirements. The article provides direction for future research to evaluate the repeal of minimum parking requirement and its effects on transport, the environment, and the economy.     

法国城市规划编制体系对我国的启示——以巴黎为例

分析了法国城市规划编制体系的特点 ,阐述了保护区规划与城市土地利用规划的关系及其特殊性 ,着重指出保护区规划的独立性及其完善的配套规定 ,并探讨了法国的城市规划编制体系对我国保护规划编制方法的借鉴意义。     

城市交通与土地使用一体化的探讨及启示

城市交通与土地使用的一体化对于城市可持续发展至关重要。立足于城市经济学,试图在理论层面理清交通与城市之间错综复杂的关系,进而在实践层面分析总结国际城市处理城市交通与土地使用一体化之间关系的成功经验。在此基础上对上海既有的规划进行反思,并对未来城市空间发展政策的导向提出建议。