Doctorat en sciences sociales, politiques et économiques / info:eu-repo/semantics/nonPublished

Recently federal policy aimed at halting decline in urban neighborhoods has included a major focus on housing rehabilitation efforts. In the case of Portland, Oregon, federally funded improvement loans for owner-occupied housing units resulted in the rehabilitation of almost four thousand homes from 1975 until 1978, over twice the number of homes rehabilitated in any other city in the nation. The purpose of the present study was to examine and analyze the city's rehabilitation loan program in two ways. First, the loan process itself was examined to ascertain whether there were any deficiencies in the loan program which should be corrected. The second, and primary, focal point was the specific neighborhoods where rehabilitation loans have been funneled. The impact of the loan programs on the neighborhoods as communicated by their residents determined how successful Portland has been in dealing with urban decline through its loan programs. Prior to gathering primary data on the neighborhoods, several secondary sources of information were used. The Portland Development Commission's in-house evaluations of the loan process demonstrated strong recipient support for the program. A survey of loan recipient files showed loans going to low income families with few assets. Although half of the loans went to married couples, a substantial number of loans went to divorced women and widows. The majority of rehabilitated homes were over fifty years old, and their median assessed value was $16,500. Secondary data was also used to look at outside perceptions of changes taking place in loan neighborhoods. Real estate trends and mortgage and home improvement loan activities suggested that the impact of the government loan programs has not yet been substantial enough to trigger changes in private policies related to the neighborhoods. Primary data for the study came from a random sample survey of four hundred persons in four Portland neighborhoods. Two neighborhoods, one in the north section of the city and one in southeast, where loans have been given, were paired with two control neighborhoods where loans were not available. The survey instrument used contained 72 variables chosen as capable of determining what the impact of the loan program has been on loan recipients, their neighbors, and their neighborhoods. Four outcomes could have stemmed from the loan programs. The first possibility was that people living in the neighborhoods where Housing and Community Development loans have been granted should feel more positive about their neighborhood than those not living in HCD neighborhoods. A second consequence could have been that HCD neighborhoods are upgrading socio-economically. Third, HCD neighborhood residents simply may not have perceived improvements in their neighborhoods, or fourth, even if they perceive improvements, they do not show significantly higher levels of satisfaction with their neighborhoods than holds true for respondents living in the control neighborhoods. The data indicated that although residents in HCD neighborhoods do perceive improvements taking place in their neighborhoods, their levels of satisfaction with their neighborhoods are not significantly higher than satisfaction levels in non-loan neighborhoods. Socio-economic changes may be taking place in the Southeast HCD neighborhood. As for the loan process, the program was rated highly by the recipients of the loans, both in in-house evaluations done for the Portland Development Commission and as reported in the neighborhood survey. The study concludes that the city's efforts provided a solid first step in developing a strong commitment to strengthening inner city neighborhoods, but it is only a first step. A stronger commitment, particularly on the part of private industry, is needed to end urban neighborhood decline.

No abstract available. / Thesis (M.T.R.P.)-University of Natal, Durban, 1997.

User participation has been regarded as an empowerment tool to help low-income people to improve housing at a low cost. It was implemented by the Community Design Workshop during the attempts at housing rehabilitation in Pointe St. Charles in the early 1970's. This thesis is focused on the long-term results of user participation employed by the CDW. Both the current physical conditions of the CDW's projects and the inhabitants' attitudes towards participation, one generation after its implementation, were studied. The research shows that the CDW's efforts involving users in housing rehabilitation not only resulted in improved housing conditions for the urban poor in the long run but had some positive impacts on the inhabitants as well. The success and failure of the CDW's work also provided empirical lessons for later participatory practice.

No description available.

[ES] Las cubiertas ajardinadas forman parte de las soluciones, diseños y sistemas constructivos de la arquitectura sostenible. El equilibrio entre las dimensiones ambiental, social y económica en aras de conseguir el máximo bienestar y desarrollo de nuestras sociedades influye en cómo se construye. La rehabilitación energética de un parque de viviendas cada día más envejecido y deteriorado permite reducir el consumo energético desde dos puntos de vista: aprovechando recursos ya existentes, al ampliar la vida útil de edificios todavía estructuralmente funcionales, pero en una condiciones térmicas, de salubridad o equipamiento deficientes; y reduciendo el consumo energético de estos edificios, con los beneficios que ello supone para el medio ambiente, la economía y el bienestar social de sus usuarios y del entorno. En la presente tesis doctoral se profundiza en el comportamiento energético y térmico de las cubiertas ajardinadas en rehabilitación, estructurándose en dos apartados que abordan el estudio de la reducción del consumo energético y las consideraciones constructivas para una correcta ejecución de estos sistemas ajardinados. En el primer apartado se analiza la distribución de temperaturas y humedades relativas en las diferentes capas de modelos reales a escala de cubiertas ajardinadas. Las conclusiones extraídas de estos datos tomados mediante data-loggers, para la ciudad de València, se comparan con el funcionamiento de los mismos sistemas constructivos de cubierta, diseñados y simulados a través de modelos informáticos. Este proceso permite estudiar no solo el comportamiento térmico de la cubierta, sino también su funcionamiento energético y el posible ahorro a conseguir en diferentes hipótesis de rehabilitación de una vivienda, considerando también la posible intervención sobre otros elementos de la envolvente térmica. El mecanismo de evapotranspiración presenta un papel importante en la disipación de calor de las cubiertas ajardinadas, por lo que se profundiza en su estudio para el caso de cubiertas autosuficientes, es decir, sin aporte de agua de riego. Este sistema de cubierta ajardinada pretende responder a la problemática escasez de agua a la que se enfrenta parte del territorio español, especialmente en la costa mediterránea en la que se ubica la ciudad de València. También se profundiza en la comprensión sobre qué variables climáticas, de entre temperatura ambiente, radiación solar y precipitaciones, son más influyentes en este proceso. La relación de la evapotranspiración con el agua almacenada, en las capas de la cubierta dispuestas a tal fin, queda patente, reduciéndose este proceso a menor disponibilidad de agua, especialmente en climas como el mediterráneo, con escasas precipitaciones y elevada temperatura ambiental y radiación solar. Todas las reflexiones obtenidas permiten confirmar las limitaciones en las pérdidas de calor por evapotranspiración derivadas de la escasez de agua, lo que conlleva la necesidad de buscar posibles soluciones que mejoren su comportamiento energético. Cada una de las situaciones estudiadas, conocidas y planteadas sus debilidades y fortalezas, permite concluir cuál es el mejor sistema constructivo de cubierta ajardinada para el caso de rehabilitación, principal aportación de este trabajo. En el segundo y último apartado, se realiza el estudio constructivo de una rehabilitación mediante el sistema de cubierta ajardinada escogido previamente. Esto permite detectar y conocer los problemas y soluciones que afrontar para conseguir una correcta ejecución, la cual supondrá mejorar la accesibilidad, mantenimiento, sostenibilidad y vida útil del sistema ajardinado de cubierta. Comprender el comportamiento energético de las cubiertas ajardinadas, así como las particularidades de instalación y construcción, permite ampliar su difusión, aplicación y los beneficios ambientales, sociales y económicos que de su uso se derivan. / [CA] Les cobertes enjardinades formen part de les solucions, dissenys i sistemes constructius de l'arquitectura sostenible. L'equilibri entre les dimensions ambiental, social i econòmica a fi d'aconseguir el màxim benestar i desenvolupament de les nostres societats influeix en com es construeix. La rehabilitació energètica d'un parc d'habitatges cada dia més envellit i deteriorat permet reduir el consum energètic des de dos punts de vista: aprofitant recursos ja existents, en ampliar la vida útil d'edificis encara estructuralment funcionals, però en una condicions tèrmiques, de salubritat o equipament deficients; i reduint el consum energètic d'aquests edificis, amb els beneficis que això suposa per al medi ambient, l'economia i el benestar social dels seus usuaris i de l'entorn. En la present tesi doctoral s'aprofundeix en el comportament energètic i tèrmic de les cobertes enjardinades en rehabilitació, estructurant-se en dos apartats que aborden l'estudi de la reducció del consum energètic i les consideracions constructives per a una correcta execució d'aquests sistemes enjardinats. En el primer apartat s'analitza la distribució de temperatures i humitats relatives en les diferents capes de models reals a escala de cobertes enjardinades. Les conclusions extretes d'aquestes dades preses mitjançant data-loggers, per a la ciutat de València, es comparen amb el funcionament dels mateixos sistemes constructius de coberta, dissenyats i simulats a través de models informàtics. Aquest procés permet estudiar no sols el comportament tèrmic de la coberta, sinó també el seu funcionament energètic i el possible estalvi a aconseguir en diferents hipòtesis de rehabilitació d'un habitatge, considerant també la possible intervenció sobre altres elements de l'envolupant tèrmica. El mecanisme d'evapotranspiració presenta un paper important en la dissipació de calor de les cobertes enjardinades, per la qual cosa s'aprofundeix en el seu estudi per al cas de cobertes autosuficients, és a dir, sense aportació d'aigua de reg. Aquest sistema de coberta enjardinada pretén respondre a la problemàtica escassetat d'aigua a la qual s'enfronta part del territori espanyol, especialment en la costa mediterrània en la qual se situa la ciutat de València. També s'aprofundeix en la comprensió sobre quines variables climàtiques, d'entre temperatura ambient, radiació solar i precipitacions, són més influents en aquest procés. La relació de l'evapotranspiració amb l'aigua emmagatzemada, en les capes de la coberta disposades a tal fi, queda patent, reduint-se aquest procés a menor disponibilitat d'aigua, especialment en climes com el mediterrani, amb escasses precipitacions i elevada temperatura ambiental i radiació solar. Totes les reflexions obtingudes permeten confirmar les limitacions en les pèrdues de calor per evapotranspiració derivades de l'escassetat d'aigua, la qual cosa comporta la necessitat de buscar possibles solucions que milloren el seu comportament energètic. Cadascuna de les situacions estudiades, conegudes i plantejades les seues febleses i fortaleses, permet concloure quin és el millor sistema constructiu de coberta enjardinada per al cas de rehabilitació, principal aportació d'aquest treball. En el segon i últim apartat, es realitza l'estudi constructiu d'una rehabilitació mitjançant el sistema de coberta enjardinada triat prèviament. Això permet detectar i conéixer els problemes i solucions que afrontar per a aconseguir una correcta execució, la qual suposarà millorar l'accessibilitat, manteniment, sostenibilitat i vida útil del sistema enjardinat de coberta. Comprendre el comportament energètic de les cobertes enjardinades, així com les particularitats d'instal·lació i construcció, permet ampliar la seua difusió, aplicació i els beneficis ambientals, socials i econòmics que del seu ús es deriven. / [EN] Green roofs are part of the solutions, designs and construction systems of sustainable architecture. The balance between the environmental, social and economic dimensions in order to achieve the maximum well-being and development of our societies influences how to build. The energy renovation of an increasingly aged and deteriorated housing stock allows energy consumption to be reduced from two points of view: taking advantage of already existing resources, by extending the useful life of buildings that are still structurally functional, but in thermal, health or equipment poor conditions; and reducing the energy consumption of these buildings, with the benefits that this implies for the environment, the economy and the social well-being of its users and the surroundings. This thesis delves into the energy and thermal behaviour of green roofs under renovation, structured into two sections that address the study of energy consumption reduction and construction considerations for proper execution of these vegetated systems. The first section analyses the distribution of temperatures and relative humidity in the different layers of real-scale models of green roofs. The conclusions drawn from these data taken by data-loggers, for the city of València, are compared with the running of the same roof construction systems, designed and simulated through computer models. This process makes it possible to study not only the thermal behaviour of the roof, but also its energy performance and the possible savings to be achieved in different housing renovation scenarios, also considering the possible intervention on other elements of the thermal envelope. The evapotranspiration mechanism plays an important role in the heat dissipation of green roofs, so its study is deepened in the case of self-sustaining roofs, that is, without irrigation water supply. This green roof system aims to respond to the problematic water shortage that part of the Spanish territory is facing, especially on the Mediterranean coast where the city of València is located. It also deepens the understanding of which climatic variables, among outdoor temperature, solar radiation and precipitation, are most influential in this process. The relationship of evapotranspiration with stored water, in the roof layers arranged for this purpose, is evident, reducing this process to less water availability, especially in climates such as the Mediterranean, with low precipitation and high outdoor temperature and solar radiation. All the reflections obtained make it possible to confirm the limitations in heat losses due to evapotranspiration derived from water scarcity, which entails the need to look for possible solutions that improve their energetic behaviour. Each of the situations studied, known and raised their weaknesses and strengths, allows us to conclude which is the best green roof construction system for the case of renovation, the main contribution of this work. In the second and last section, the constructive study of a renovation is carried out using the previously chosen green roof system. This makes it possible to detect and learn about the problems and solutions to be faced in order to achieve correct execution, which will mean improving the accessibility, maintenance, sustainability and useful life of the green roof system. Understanding the energy behaviour of green roofs, as well as the particularities of installation and construction, allows to expand its diffusion, application and the environmental, social and economic benefits derived from its use. / Garcia Borràs, J. (2023). Estudio hidrotérmico de cubiertas ajardinadas. Análisis y recomendaciones de diseño para una mayor eficiencia energética [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/195341