A knowledgeA knowledgeA knowledgeA knowledge----based analytic approach based analytic approach based analytic approach based analytic approach

for sustainable projects for sustainable projects for sustainable projects for sustainable projects

in outlying urban areasin outlying urban areasin outlying urban areasin outlying urban areas

Stefano Pili, Valeria Saiu

"La riqualificazione sostenibile delle “periferie” della Sardegna. Impostazione di "La riqualificazione sostenibile delle “periferie” della Sardegna. Impostazione di "La riqualificazione sostenibile delle “periferie” della Sardegna. Impostazione di "La riqualificazione sostenibile delle “periferie” della Sardegna. Impostazione di

una metodologia per il recupero“una metodologia per il recupero“una metodologia per il recupero“una metodologia per il recupero“

by Valeria Saiu PhD, developed on the Cagliari's Architecture Department

financed by Regione Sardegna (years 2010-2012)

with the supervisor prof. Antonello Sanna

"Definizione di una metodologia per l’implementazione di un sistema di aiuto "Definizione di una metodologia per l’implementazione di un sistema di aiuto "Definizione di una metodologia per l’implementazione di un sistema di aiuto "Definizione di una metodologia per l’implementazione di un sistema di aiuto

alla decisione, in ambiente GIS, finalizzato all’integrazione dell’efficienza alla decisione, in ambiente GIS, finalizzato all’integrazione dell’efficienza alla decisione, in ambiente GIS, finalizzato all’integrazione dell’efficienza alla decisione, in ambiente GIS, finalizzato all’integrazione dell’efficienza

energetica degli edifici residenziali nei processi di formulazione e valutazione di energetica degli edifici residenziali nei processi di formulazione e valutazione di energetica degli edifici residenziali nei processi di formulazione e valutazione di energetica degli edifici residenziali nei processi di formulazione e valutazione di

politiche, piani o programmi in ambito urbano"politiche, piani o programmi in ambito urbano"politiche, piani o programmi in ambito urbano"politiche, piani o programmi in ambito urbano"

Phd thesis by Stefano Pili, Phd on Land Engineering (XXIV cycle) at the Cagliari

University (Italy)

with the supervisor prof. Emanuela Abis

L’analisi storica

I caratteri del suolo

Le infrastrutture

L’analisi tipo-morfologica

La selezione dei casi studio

sustainablesustainablesustainablesustainable urban designurban designurban designurban design

> central role in the development of future policy

> one of the main engines driving the renewal of instruments

for regional management.

Cities consume 60606060----80%80%80%80% of the world’s total energy (OECD, 2010)

Since the 1990s cities have played an increasingly central role in

determining strategies for sustainable development

1994 1994 1994 1994 ---- Aalborg Charter Aalborg Charter Aalborg Charter Aalborg Charter

sustainability goals on the urban scale > indicators

"our policy-making and controlling efforts (...) on different types of

indicators, including those of urban environmental quality, urban flows,

urban patterns, and, most importantly, indicators of an urban systems

sustainability”sustainability”

> methods for analyzing and monitoring the design of urban projects

integration of study of the energy efficiency of buildings with issues of

environmental and economic sustainability of plans

and to include a system of analysis that can evaluate the social equity of

urban 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 plans

with themes regarding the environmental and landscape sustainability of urban transformation.

1954

2006

Claru BiddaClaru BiddaClaru BiddaClaru Biddadetached free-standing dwellings

Pitz’e SerraPitz’e SerraPitz’e SerraPitz’e Serraapartment buildings

Santa LuciaSanta LuciaSanta LuciaSanta Luciarow housing

urban qualityurban qualityurban qualityurban quality:

public space,

green areas and services,

demand for mobility,

social composition of the population,

(...)

building qualitybuilding qualitybuilding qualitybuilding quality:

energy sustainability of buildings,

(...)

Through these first analyses, a knowledge-based approach -

useful for guiding decision-making towards strategic planning

choices that can be verified in greater detail in a subsequent

design phase - began to take shape.

Target value

thresholds

Urban quality Green and public space

Plan implementation phase

Mobility needs

Relationship with context

Social integration

Demographic data

Municipal value

Building quality

Envelope efficiency

heat transfer coefficient H [W/k]

H value obtained through current standard

regulations

DHW solar panel

Potential production [kWh year]

DHW need [ kWh year]

(UNI 11300 part 2)

PV solar panel

Potential production [kWh year]

Electric need [ kWh year]

3000 kWh year for unit

design phase - began to take shape.

EvaluatingEvaluatingEvaluatingEvaluating urbanurbanurbanurban qualityqualityqualityquality

Claru Bidda

Housing: 55%

Green and services: 22%

Roads: 23%

Pitz'e Serra

Housing: 55%

Green and services: 27%

Roads: 18%

Santa Lucia

Housing: 40%

Green and services: 452%

Roads: 15%

PopulationPopulationPopulationPopulation

Apartment-building and detached dwellings

areas, showed a prevalence of working-age

population, in the ranges from 30 to 44 and 45 to

60. The high rate of singles presence in the

apartment building could be related to the smaller

house dimension.

The greater variety of dwelling size (90 sqm, 80

sqm, 70 sqm and 45 sqm) is a significant factor in

the evaluation of the current and potential social

mix in the area and also explains the high

percentage of rentals (40%) as well as the high

incidence of nuclear families.incidence of nuclear families.

In the row house area, the larger sizes of the

dwelling units permits a great number of larger

family units to reside there while maintaining a low

crowding index and thus good urban quality.

For all three areas in the study, occupancy rates

are higher than the municipal average with the

exception of the detached housing area which

maintains, at least in part, its character as a

summer colony. outside the

Row housing and free-standing dwelling areas shows more

mobility demand to outside than the municipality average

The location near the major metropolitan connection road has

attracted users characterized by the need for great mobility,

especially people employed in the commercial sector or

businesses in general.

Assessing building quality : Based on available data, the evaluation is focused on the efficiency

of the envelope and the potential use of renewable energy sources .

H = 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-value

Uwind= Windows U-value Swind = Window surface

Uroof = Roof U-value Sroof = Roof surface

Ubase = Basement U-value Sbase = base surface

Envelope efficiency

Data data source Data data source

Geometry projects N° of floors Bing Map

Glazing ratio projects Roof type Bing Map

Average floor height projects Wall color Bing Map

Structures and

material Typology

Mechanical system

efficiencyMissing data

Ubase = Basement U-value Sbase = base surface

Ustair = Stair well wall U-Value Sstair = Stair well wall surface

Residential Energy Toolbox base data

Comparison between theoretical potential of solar panels for DHW and electricity and their

domestic needs.

ES = I*C*AS*PVm/ NeedE (2)

DHWS = I*C*AS*DHWm/ NeedDHW (3)

Where:

EF = Electric need fulfilling DHWF = DHW need fulfilling

Potential use of renewable energy sources

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)

Conclusions

Despite the simplifications deriving from the analysis scale, the methodology

is able to create thematic maps and synthetic graphs from a set of indicators

that could be useful to provide guidelines in developing plan strategies

Further research

extending the analysis to other typological/morphological models present in

those areas

Define a more complete set of indicator to asses other aspects of urban

sustainability

Put the methodology in a GIS software to develop a useful tool for

knowledge construction as well as for design alternative projects

This opens to a Spatial Multicriteria Analysis tools implementation to

assess between alternative project and scenarios.