Green roofs

Introduction

Green roofs - oases in the urban area

A green roof is a roof which is partially or entirely covered by vegetation and soil or growing substrate. Therefore, urban environments in particular, which contain a great deal of built-up concrete areas and have the minimum of greenery, are discovering the potential of green roofs as one possible measure to prevent the formazion of heat islands, i.e. places with a noticeably higher temperature. Another of the main advantages of green roofs is their retention capacity, with rainwater collecting and gradually evaporating.

The aim of the analysis conducted by the Data Platform Department was to determine the maximum possible capacity of suitable green roofs where the transformation would make sense under certain conditions. The data showed that Prague has great unused potential, where up to 143 ha of green roofs (a total of 812 buildings) could be installed just on buildings owned by the city and its boroughs (category I), which in terms of area is equivalent to approximately 2 Stromovka parks. If green roofs are installed on privately owned buildings, the potential is far higher. Another outcome of the analysis is a list and description of buildings on which green roofs would be installed. This data needs to be used in line with the processor’s needs, and so we publish this data in open format and make it freely available for use.

The procedure used to filter and divide up the data, including a description of the individual categories and limitations of the study, are described in more detail in the Green Roofs Analysis document, which can be downloaded below.

Function

  • Retain rainwater and slows runoff
  • Protect roof damp-proofing insulation
  • Reduce temperature fluctuations

Benefits

  • Produce oxygen and retains carbon dioxide
  • Reduce dust and noise
  • Improve the appearance of cities and the landscape
  • Create a habitat for insects
  • Serve a community purpose

Green Roofs Analysis

The Green Roofs analysis can be downloaded below.

Downloadable PDF document (689 kB)

Map of the potential of green roofs

Roofs which can be converted to greenery under certain conditions are divided up into 4 categories. The most suitable roofs for this transformation are in category I, followed by, according to suitability, categories II, III and IV. The data from these categories can be displayed in the visualization either individually, or the categories may be displayed.

Category Number of building Area in ha
Category I 812 143
Category II 2 679 364
Category III 10 633 1 179
Category IV 21 339 1 659

Zooming out of the map shows the maximum number of buildings in each individual category, including the size of the areas.

Mapa potenciálu zelených střech

Roofs with greening potential

Map visualization of buildings in Carto.The visualization can also be opened in a new panel.

Comparision of the area of Prague´s  parks and the potential of green roofs

Source: www.lhmp.cz

Pollutant absorption potential

Annual pollutant absorption potential upon greening of Category I (143 ha size). Source: www.opatreni-adaptace.cz

Rainfall intensity affect  the degree of water retention

Water retention was only analysed for extensive greening (up to 4 cm). Source: www.researchgate.net

Data resources

Green roofs - map layers

GIS layers used for this analysis can be found at www.geoportalpraha.cz/cs/opendata

Potenciál zelených střech

Mapové podklady k analýze potenciálu zelených střech v Praze. Výstupy vychází z mapových podkladů o podlažnosti budov, vlastnictví a využití území od Institutu plánování a rozvoje hlavního města Prahy.

Datové soubory
Name Format
Budovy vhodné pro zelené střechy - GeoJSON GeoJSON STÁHNOUT
Budovy vhodné pro zelené střechy - Shapefile SHP STÁHNOUT
Cataloging entry
Label Value
Periodicita aktualizace bez aktualizace
Licence Creative Commons CCZero
Poskytovatel dat Operátor ICT a. s.
Odkaz do katalogu http://opendata.praha.eu/dataset/potencial-zelenych-strech