"La riqualificazione sostenibile delle “periferie” della Sardegna. Impostazione diuna metodologia per il recupero“by Valeria Saiu PhD, developed on the Cagliaris Architecture Departmentfinanced by Regione Sardegna (years 2010-2012)with the supervisor prof. Antonello Sanna"Definizione di una metodologia per l’implementazione di un sistema di aiutoalla decisione, in ambiente GIS, finalizzato all’integrazione dell’efficienzaenergetica degli edifici residenziali nei processi di formulazione e valutazione dipolitiche, piani o programmi in ambito urbano"Phd thesis by Stefano Pili, Phd on Land Engineering (XXIV cycle) at the CagliariUniversity (Italy)with the supervisor prof. Emanuela Abis
L’analisi tipo-morfologicaLa selezione dei casi studio
Cities consume 60-80% of the world’s total energy (OECD, 2010) 60-sustainable urban design> central role in the development of future policy> one of the main engines driving the renewal of instrumentsfor regional management.
Since the 1990s cities have played an increasingly central role indetermining strategies for sustainable development1994 - Aalborg Chartersustainability goals on the urban scale > indicators"our policy-making and controlling efforts (...) on different types ofindicators, including those of urban environmental quality, urban flows,urban patterns, and, most importantly, indicators of an urban systemssustainability”> methods for analyzing and monitoring the design of urban projectsintegration of study of the energy efficiency of buildings with issues ofenvironmental and economic sustainability of plansand to include a system of analysis that can evaluate the social equity ofurban development.
2005, Piano Paesaggistico Regionale of Sardinia (PPR)> local urban plans were required to be adapted to the Regional Landscape Plan,> local governments were called upon to integrate their land-use planswith themes regarding the environmental and landscape sustainability of urban transformation.
quality:urban qualitypublic space,green areas and services,demand for mobility,social composition of the population,(...) quality:building qualityenergy sustainability of buildings,(...)Through these first analyses, a knowledge-based approach -useful for guiding decision-making towards strategic planningchoices that can be verified in greater detail in a subsequentdesign phase - began to take shape. thresholdsTarget value Plan implementation phaseUrban quality Green and public space Relationship with context Mobility needs Municipal value Social integration Demographic data H value obtained through current standard Envelope efficiency regulationsBuilding quality heat transfer coefficient H [W/k] DHW need [ kWh year] DHW solar panel (UNI 11300 part 2) Potential production [kWh year] Electric need [ kWh year] PV solar panel 3000 kWh year for unit Potential production [kWh year]
Evaluating urban qualityClaru BiddaHousing: 55%Green and services: 22%Roads: 23%Pitze SerraHousing: 55%Green and services: 27%Roads: 18%Santa LuciaHousing: 40%Green and services: 452%Roads: 15%
Population Apartment-building and detached dwellingsareas, showed a prevalence of working-agepopulation, in the ranges from 30 to 44 and 45 to60. The high rate of singles presence in theapartment building could be related to the smallerhouse dimension. The greater variety of dwelling size (90 sqm, 80sqm, 70 sqm and 45 sqm) is a significant factor inthe evaluation of the current and potential socialmix in the area and also explains the highpercentage of rentals (40%) as well as the highincidence of nuclear families. In the row house area, the larger sizes of thedwelling units permits a great number of largerfamily units to reside there while maintaining a lowcrowding index and thus good urban quality. For all three areas in the study, occupancy ratesare higher than the municipal average with theexception of the detached housing area whichmaintains, at least in part, its character as asummer colony. outside the
Row housing and free-standing dwelling areas shows moremobility demand to outside than the municipality average The location near the major metropolitan connection road hasattracted users characterized by the need for great mobility,especially people employed in the commercial sector orbusinesses in general.
Assessing building quality : Based on available data, the evaluation is focused on the efficiencyof the envelope and the potential use of renewable energy sources .Envelope efficiencyH = Uwall*Swall + Uwind*Swind + Uroof*Sroof + Ubase*Sbase + Ustair*Sstair (1)Where:H = global transmission heat transfer coefficient [W/k]Swall = Wall Surface Uwall = Wall U-valueUwind= Windows U-value Swind = Window surfaceUroof = Roof U-value Sroof = Roof surfaceUbase = Basement U-value Sbase = base surfaceUstair = Stair well wall U-Value Sstair = Stair well wall surfaceResidential Energy Toolbox base dataData data source Data data sourceGeometry projects N° of floors Bing MapGlazing ratio projects Roof type Bing MapAverage floor height projects Wall color Bing MapStructures and Mechanical system Typology Missing datamaterial efficiency
Potential use of renewable energy sources Comparison between theoretical potential of solar panels for DHW and electricity and theirdomestic needs. ES = I*C*AS*PVm/ NeedE (2) DHWS = I*C*AS*DHWm/ NeedDHW (3) Where: EF = Electric need fulfilling DHWF = DHW need fulfilling NeedE = Electric need, 3000 kWh by units I = solar year irradiation [kWh/mq year] C = surface azimuthal and zenithal parameters PVm = PV panel average efficiency 14% AS = available roof surface parameter [sm] DHWm = DHW panel average efficiency, 65% DHW Need = Domestic Hot Wather need (UNI 11300 part 2)
ConclusionsDespite the simplifications deriving from the analysis scale, the methodologyis able to create thematic maps and synthetic graphs from a set of indicatorsthat could be useful to provide guidelines in developing plan strategiesFurther researchextending the analysis to other typological/morphological models present inthose areasDefine a more complete set of indicator to asses other aspects of urbansustainabilityPut the methodology in a GIS software to develop a useful tool forknowledge construction as well as for design alternative projectsThis opens to a Spatial Multicriteria Analysis tools implementation toassess between alternative project and scenarios.