Seventh Interna;onal Conference on Informa;cs and Urban and Regional Planning Cagliari, 10‐12 May, 2012 Iden%ﬁca%on and georeferencing of second homes: a planning support in the Sardinian coastal municipali%es Alessandra Cappai, Iván Alvarez León, Maurizio Minchilli Facoltà di Archite/ura di Alghero, Università degli Studi di Sassari Research funded by the Regional Law 7/2009 “PromoFon of scienFﬁc research and technological innovaFon in Sardinia”
Introduc%on Object of the research: to build an informaFon system that allows to deﬁne the amount and distribuFon of second homes in the Sardinian coastal land. Methodology: based on the integraFon of data in a geo‐staFsFcs integrated environment such as that made available by Geographically based InformaFon Systems Contents : ‐ Methodology for homogenizaFon of the collected database ‐ Monitoring of second homes’ number ‐ LocaFon of second homes in the land through cadastral cartography
1. Choice of case studies STEP 1: coastal municipaliFes idenFﬁed by the STEP 4: municipaliFes that collaborate giving Sardinian Piano PaesaggisFco Regionale or PPR us the requested informaFon (Regional Landscape Plan) 165 20 STEP 2: number of unoccupied dwellings provided by ISTAT with a percentage of unoccupied homes of more than 30% with respect to their total 56 STEP 3: municipaliFes with a total of more than 2000 property units 35
2. Methodology for homogeniza%on of the collected database In order to calculate the number of dwellings registered as "second homes", it was decided to refer to those municipal taxes related to the condiFon of residence. ‐ ICI (Municipal Property Tax), which following the ﬁscal decree 93/2008 is abolished for the ﬁrst houses (usual residence involving enrollment in the residents’ Registry in the municipality where the property is located), and is then charged to the owners of second homes and for other types of luxury homes, villas, castles and palaces. ‐ TARSU (Urban Solid Waste Tax): municipaliFes choose the criteria by which they calculate this tax, some of them diﬀer in the rate between the ﬁrst and second homes, others based on the surface area or the number of rooms and so on. Through the analysis carried out we will come to calculate the number of second homes "oﬃcially" registered as such, though knowing that there is a large number of second homes registered as the ﬁrst one, but actually used only during the summer months, therefore they are diﬃcult to detect.
3. Monitoring of second homes’ number The database contains as many rows as there are ICI or TARSU taxpayers, therefore, if a house belongs to X diﬀerent owners, the Sheet Cadastral Subaltern Cadastral % Months Address Owners Map Category Possession Possession residencesame will appear in the database X Fmes, 2 1576 50 A02 10000 2 Via Guia Saluzzoaccording to all the owners who pay tax 2 1055 1 A02 357 5 Via dei Mille s/n Valledoriaaccording to the percentage of ownership. 2 1055 3 A02 357 6 Via dei Mille s/n Valledoria 2 1055 4 A02 357 6 Via dei Mille s/n Valledoria 2 1055 2 A02 357 12 Via dei Mille s/n Valledoria 2 1055 1 A02 358 12 Via dei Mille s/n Castelsardo 2 1055 2 A02 358 12 Via dei Mille s/n CastelsardoThe operaFon of homogenizaFon has been Typical database based on ICI taxpayers supplied by the based on skimming the database through Tax Oﬃce which we delete the rows that repeat the same Sheet, Cadastral Map, Subaltern.
3. Monitoring of second homes’ number Calcula;on of second homes through the data collected in the Public Administra;on (ICI and TARSU taxes) and comparison with data from Istat 2001.
4. Loca%on of second homes in the land through cadastral cartography In order to locate second homes in the land, we proceed by cross referencing cadastral data present in the revised municipal databases and the available cadastral cartography. The diﬃculty encountered in this phase of work is due to the mismatch of the cadastral data: municipal databases refer to the Buildings Cadastre, while the only available georeferenced or digiFzed cartography is that of the Land Cadastre. Following the uniﬁcaFon of Land and Buildings Cadastre in a single enFty (Land Agency), it has been made mandatory to unify the codes for buildings and land, giving priority to the la/er. In recent years it has been carrying out a process called "Alignment", through which every building is associated with the Sheet and Cadastral Map code of the land in which it is located. The following cartography has been used: ‐ numeric CTR in various versions, both vectorial and integrated in GeoDB structure; ‐ Orthophotos from various periods (both based on historical sFlls and on new digital coverage) with GSD from 1m to 0.1m; ‐ large‐scale vectorial cartography of the coastal municipaliFes; ‐ planning at the local level (P.di F., PRG and current PUC) for an iniFal idenFﬁcaFon of areas of tourism.
Density of Second Homes occupied in each plots Number of Second Homes
Discrepancies between tha data base of Second Homes and the reality.
Discrepancies plots occupied by Second Homes “uncertains plots”
Summary table of the results obtained by the process of cross referencing data with cartography Empty Empty dwellings Not Not Municipality dwellings Georeferenced Uncertains Monitoring ICI identifiable georeferenced ISTAT Alghero 8720 10447 118 7305 1060 3024 Stintino 3347 4728 9 0 - 4728 Sorso 4833 6049 100 4794 292 1155 Castelsardo 1066 2360 6 1899 354 455 Valledoria 1285 1965 - 0 - 1965 Badesi 1111 1508 3 1033 113 472 Trinità dAgulta 3466 4805 9 3717 390 1079 Santa Teresa di Gallura 4410 6912 43 5086 916 1783 Palau 4074 4471 12 3819 288 640 Arzachena 8198 9350 64 1687 328 7599 La Maddalena 2773 8864 73 7012 1851 1779 Golfo Aranci 3572 5146 19 897 249 4230 Loiri Porto San Paolo 2236 4171 19 3413 177 758 Muravera 3470 4939 336 2925 1330 1678 Castiadas 513 1680 1148 380 129 152 Villasimius 3752 4933 0 4803 0 130 Maracalagonis 1585 1379 339 - - 1040 Pula 3180 2736 0 1705 584 1031 Domus de Maria 921 1388 239 787 145 362 Teulada 767 699 30 343 72 0 TOTALE 63279 88530 2567 51605 8278 34060
System occupancy of second homes in the ﬁrst three km of the coastline Diagram of system occupancy Result of system occupancy First km of the coastline‐municipaliFes Second km of the coastline‐ municipaliFes Third km of the coastline‐ municipaliFes
Regional Landscape Plan (PPR) + Second homes map
Thanks for your a/enFon !!! firstname.lastname@example.org‐ Alessandra Cappai email@example.com –Iván Alvarez firstname.lastname@example.org – Maurizio Minchilli