* AVENUES – GSU ; EA 7284. University of Technology of Compiègne – France

1. Journée du 26 juin 2013 – Lamsade Université Paris Dauphine Un outild’aide à la décision pour l’urbanismerèglementaireApplication au Plan Local d’Urbanisme (PLU) de Toulouse Aurélie PREVOST*, Nathalie MOLINES* , Jean BANDET * * * AVENUES – GSU ; EA 7284. University of Technology of Compiègne – France ** Toulouse Métropole – DGDUD – Direction Planification et Urbanisme – Toulouse - France

2. PhD research, collaboration with the city of Toulouse (CIFRE PhD) In the regulatory planning department. Objective of the research : to create an aiding decision tool for regulatory planners, that allow them to anticipate and understand the impacts of urban regulations that can be complex At the scale of the city, because the PhD focuses on local plans (PLU) and its regulations A new tool to assess the effects of the regulations on urbanforms : aims and objectives

3. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Definition and content of the french local plans (PLU) The PLU (local plan) Content 1. Territorial diagnosis Contains a PADD = territorial management priorities with a crosscutting approach (city council project for the development of the city) 2. Traduction of the PADD’s guideline into a statutory zoning and a set of regulations for each zone - Traditionaly dealing with: land occupation, building shape and density, layout of the plot, and amenities (public facilities) – 14 statutory articles ! (16 with Grenelle law) 3. + (if required) : environmental assessment chapters : ex-ante and ex-post assessment of the plan with indicators

4. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives • Environmentalassessmentprocess for some local plans with an ex-ante and ex-post evaluation = indicators • But …. Thoseindicatorsseem not to beadapted to assess the impacts of the regulationschosen for the different zones : • theyseem to be more useful for ecological public managment of the city thanurban and regulatorymanagment …. Due to the complexity of the relations between the regulations and the « urbanenvironment » as a system  Aims and objectives of the research

5. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives -- Aims and objectives of the research As an aidingtool for statutoryplanners, the research tries to overcomethat gap, focusing on 3 traditionnalregulatorythemescontained in the plans : building shape and density ; layout of the plot and amenities. They are part of the definition of the « urbanintensity », and participate to some aspects of sustainable planning

6. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Comparison of statutory zones and assessment of the local plan : Scales of the zone and the parts of each zone 1. Definition of the corpus of indicators 2. Synthesis and agregation Electre tri willallow us to rank the 5 zones, using « profiles » thatseparatecategories of assessment. The profiles are based on an analysis of the whole city Principal component analysis Multicriteriaanalysis ELECTRE TRI Building scale Complementarytools : Analysis of the building fabricthanks to multivariateanalysis (statistical) ACP et CAH

7. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives First aim : create a corpus of indicators which reflects the evolutions and the current morphological situation of each zone of the plan 3 traditional regulatory issues : Density : 5 indicators Unbuilt areas : 3 indicators Amenities : 5 indicators

8. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Example of an « amenity» criteria Each zone of the plan contains a lot of geographicalobjectscalled « units of zones » Wecalculate the surfacic rate of each unit of zone, covered by the amenity ; laterwecanassess the territoryatthisscalewithElectre tri

9. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Agregation : ex-post evaluation of thE « amenities »using ELECTRE TRI The ex-post agregation is made on the 3 traditional regulatory themes contained in the plans : building shape and density ; layout of the plot and amenities.

10. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Agregation : ex-post evaluation of thE « amenities »using ELECTRE TRI For amenities :the goal is to assess the unit of zones, regarding the amenities contained. • Benefits for planners : • where are the lacks in terms of public facilities ? • in wich zone couldweprioritize public action to developamenities ? • is the number of amenities consistent with the main « function » of the zone (industrial, housing, services) • is the number of amenities consistent with the builtdensity of the zone allowed by the local plan?

11. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Agregation : ex-post evaluation of thE « amenities »using ELECTRE TRI • 5 indicators • Surfacic rate of zone covered by the buffer around public transportation stations • Surfacic rate of zone covered by daily-life shops spots (shops micro-areas) • surfacic rate of zone covered by the buffer arounddaily-life shops places • Surfacic rate of zone covered by public green areas or green network • - Surfacic rate of zone covered by the buffer around a school or a nursery

12. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Agregation : ex-post evaluation of thE « amenities »using ELECTRE TRI Definition of the « profiles » : 2 methods are used for the definition of the « profiles » : 1. First one : Based on arbitrarythresholds : - profile 3 : 25% of the unit iscovered - profile 2 : 50% iscovered - profile 1 : 75% iscovered 2. Second one : based on the real distribution of the datas, for the whole city Using a K-meandiscretisation on the results of eachindicatorscalculated for the unit of the zones for the hole city Profile 1 Profile 2 Profile 3 Result of K-means discretization of the distribution for the Surfacic rate of each unit of zone covered by public transportation network : the red points represent the profiles

13. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Agregation : ex-post evaluation of thE « amenities »using ELECTRE TRI • Parameters : • Indifference and preference thresholds are defined as 5 and 10 % • - No veto is defined • Weigh is the same on every criteria • the cut threshold (λ ), for the reference tests is chosen equal to 0,76 • Robustness analysis is done later on every parameter, and profiles • We only give the results of the pessimistic procedure of Electre tri

14. 5 indicators of amenities ; profiles defined by 25 -50 -75% Cutthreshold stable on [0,7 ;0,8] 5 indicators of amenities ; profiles definedusing K-meansdiscretization. Cutthreshold stable on [0,7 ;0,8] Best results : lots of amenities Worst results Numerous incomparabilities of the action = the unit of zone is assigned in the worst class in pessimistic procedure, and on the 2 best ones in optimistic procedure

15. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Agregation : ex-post evaluation of thE « amenities » using ELECTRE TRI Center of the city K-means methods for profile is sensibly more strict than the arbitrary method

16. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Ex ante analysis to validate zoning and regulatorychoicesbefore the approbation of the local plan Toulouse’s city councilprescribed the creation of a new local plan in march 2011. One of the new objective for that local plan is to create a « urbanism - transportation network – public facilitiesconsistency »  createunits of zones and rules(maximal heigh of building allowed) thatgive more density close to the transportation network first, but also public facilities  on the opposite, if some areas dont respondwell to that objective, itimplies to change rules (heigh of buildings) and allowlessdensity on those areas

17. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Ex ante analysis to validate zoning and regulatorychoicesbefore the approbation of the local plan • The methodused by planners to modify the plan : • To Create a cartography of the currentstatutory zoning withsome public facilities and the buffer aroud the public transportation network • To define, based on theirexperience and knowlegde of the territory, the new units of zones, that are planned to allow more density, (or less) • « Expert and experiencebasedmethod » The purpose of implementing the indicatorscreated and later, ELECTRE TRI is to validate the choicespreviously made by planners, before final approbation

18. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives Ex ante analysis to validate zoning and regulatorychoicesbefore the approbation of the local plan Method : 1. We calculate the 5 indicators on the units intially defined by planners 2. We use ELECTRE TRI to assess the global « rate of amenities » of each unit. If the result is good, we can validate more density. • Parameters : • - profiles defined by 25% - 50% - 75% of coverage • Indifference and preference thresholds : 5 % and 10 % • veto on the indicator of public transportation network : v= 15% : reflects the fact that it is the first criteria to take into account to allow more density • weigh similar on every indicator • cut threshold (λ) equal to 0,76 •  Every parameter is tested later

19. Results : Globally, where the plannersdecided to allow more density, (inside the buffer around transportation stations), the resultgiven by multicriteriaanalysisisalso good Wheretheydecided to lower future density of buildings, mostly out of the buffer, the resultgiven by Electre tri is not the best ; a lot of incomparabilities are calculated. Those are assigned in the worst classes with the pessimisticprocedure. For the exceptions : after discussion with the planners, someother planning issues made themdecideotherway : - create a urbanprojectwith mixed urbanforms (Eco district, morphological transitions…) - limitate the densitybecause the capacity of city managment networks is not sufficientyet - limitatedensitybecauseanotherprojectnearby must befinished in priority

20. approach and developments Planning system, local plan Aims/objectives of the research Ex-post assessmentusingElectre tri Ex-ante assessment Conclusion, perspectives • An ex-post analysis has been made on the 3 traditional issues of regulatory planning : density, unbuilt private areas, amenities. • Ex-post analysis with ELECTRE TRI: Aiding tool for planners, help them to understand the impacts of regulations before modifying the rules • Ex-ante analysis with ELECTRE TRI : allow planners to justify and validate choices But… those methods must be completed by discussions with experts, since knowlegde cannot be replaced by models due to complexity Conclusion and perspectives

21. Thankyou for your attention