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Evaluation of methods for calculating the green roof potential on already existing buildings in urban areas.

Rauhala, Malin LU (2019) FMIL01 20191
Environmental and Energy Systems Studies
Abstract
This study evaluates and compares four green roof methods with the purpose to calculate how many green roofs that potentially can be built on already existing buildings in a city. The methods concern the cities Braunschweig, Thessaloniki, Lisbon, and Lund. Geospatial Information Systems and remote sensing analysis are used as tools in all of the methods. Furthermore, this study observes the criteria that have been chosen in the methods and examines the possibility to create a similar method for Malmö in Sweden. Relevant stakeholders, with knowledge on green roof technology and urban planning, give their opinion in interviews. The future for green roofs in Malmö, and what hinders a faster expansion, is also discussed.

Roof slope and... (More)
This study evaluates and compares four green roof methods with the purpose to calculate how many green roofs that potentially can be built on already existing buildings in a city. The methods concern the cities Braunschweig, Thessaloniki, Lisbon, and Lund. Geospatial Information Systems and remote sensing analysis are used as tools in all of the methods. Furthermore, this study observes the criteria that have been chosen in the methods and examines the possibility to create a similar method for Malmö in Sweden. Relevant stakeholders, with knowledge on green roof technology and urban planning, give their opinion in interviews. The future for green roofs in Malmö, and what hinders a faster expansion, is also discussed.

Roof slope and available roof area are used as criteria in all of the four methods. Other criteria found useful are weather conditions like sunlight availability as well as waterproofing membrane layer and load-bearing capacity. The latter is very important to incorporate in the method since it highly affects the result.

The evaluated green roof methods follow a very similar structure. Differences depend on the initial aims, the additional tools that were used, the available input data and the scenarios that were chosen. Only one of the methods includes a field study. However, it is concluded by some of the researchers that field studies and in-situ measurements should be added to their method to improve accuracy. A sensitivity -and uncertainty analysis should also be performed. Moreover, it can be convenient to use a drone to collect both remote images and detailed images of buildings.

The people interviewed in this study believe that the number of green roofs will eventually increase in Malmö. The answers also demonstrate that there should be enough input data to start to create a green roof method for Malmö. The respondents appear positive towards it. However, one of the most difficult parts would be to find the load-bearing capacities of all roofs. Moreover, at the moment there exist no political requirements or subsidies in Sweden, compared to Germany, that requires or promotes more green roofs to be built. Therefore, depending on the development of this matter, a green roof method may be of more interest in the future. However, one can also argue the opposite. If a green roof method was created and used in Malmö now, it could become an argument to implement supporting laws or subsidies to increase the number.

Other things that may hinder a faster expansion of green roofs in Malmö are building permits, finances and a general lack of knowledge. Available information on green roof technology needs to be distributed continuously so that more people understand the concept better.

It would be interesting to do further investigations and study the laws and subsidies connected to green roofs in Germany. Can Sweden adopt a similar approach? It would furthermore be useful to collect and compile information about the physical properties of all roofs in Malmö. Roofs can be considered as space for not only vegetation but also for solar cell systems or water retention systems. Moreover, it would be interesting to follow-up if the green roof methods analysed in this study have been implemented and been useful in the chosen study areas. (Less)
Abstract (Swedish)
Denna studie utvärderar och jämför fyra grönatakmetoder med syftet att beräkna hur många gröna tak som potentiellt kan byggas på redan befintliga byggnader i en stad. Metoderna rör städerna Braunschweig, Thessaloniki, Lissabon och Lund. Geografiska informationssystem och fjärranalys används som verktyg i alla metoderna. Vidare observerar denna studie de kriterier som valts ut i metoderna och undersöker möjligheten att skapa en liknande metod för Malmö i Sverige. Relevanta intressenter, med kunskap om grönatakteknologi och stadsplanering, ger sina åsikter om huruvida en sådan metod är intressant eller inte. Framtiden för gröna tak i Malmö, och vad som motverkar en snabbare expansion, diskuteras också.

Taklutning och tillgänglig takareal... (More)
Denna studie utvärderar och jämför fyra grönatakmetoder med syftet att beräkna hur många gröna tak som potentiellt kan byggas på redan befintliga byggnader i en stad. Metoderna rör städerna Braunschweig, Thessaloniki, Lissabon och Lund. Geografiska informationssystem och fjärranalys används som verktyg i alla metoderna. Vidare observerar denna studie de kriterier som valts ut i metoderna och undersöker möjligheten att skapa en liknande metod för Malmö i Sverige. Relevanta intressenter, med kunskap om grönatakteknologi och stadsplanering, ger sina åsikter om huruvida en sådan metod är intressant eller inte. Framtiden för gröna tak i Malmö, och vad som motverkar en snabbare expansion, diskuteras också.

Taklutning och tillgänglig takareal används som kriterier i alla de fyra metoderna. Andra kriterier som visade sig vara användbara är väderförhållanden såsom tillgängligt solljus samt vattentätt takskikt och bärförmåga. Det senare är mycket viktigt att inkorporera i metoden eftersom det starkt påverkar resultatet.

De utvärderade grönatakmetoderna följer en mycket liknande struktur. Skillnader beror på de initiala målen, de ytterligare verktygen som användes, tillgängliga inmatningsdata och de scenarier som valdes. Endast en av metoderna inkluderar en fältstudie. Emellertid dras slutsatsen av några av forskarna att fältstudier och mätningar på plats bör adderas i deras metod för att förbättra noggrannheten. En känslighets -och osäkerhetsanalys bör också utföras. Dessutom kan det vara användbart med en drönare för att samla ihop bilder på byggnader, både från långt och kort avstånd.

De personer som intervjuats i denna studie tror att antalet gröna tak så småningom kommer att öka i Malmö. Svaren visar också att det bör finnas tillräckligt med inmatningsdata för att börja skapa en gröntakmetod för Malmö. Respondenterna verkar positiva till det. En av de svåraste uppgifterna skulle dock vara att hitta bärkapaciteten för alla tak. Dessutom finns det inga aktuella politiska krav eller subventioner i Sverige, i jämfört med Tyskland, som kräver eller främjar att fler gröna tak byggs. Beroende på utvecklingen av denna fråga kan det bli mer intressant att använda en grönatakmetod i framtiden istället. Man kan dock också argumentera motsatsen. Om en grönatakmetod skapades och användes i Malmö idag, skulle den kunna bli ett argument för att införa lagar eller subventioner för att öka antalet.

Andra saker som kan hindra en snabbare expansion av gröna tak i Malmö är bygglov, ekonomi och en allmän brist på kunskap. Tillgänglig information om grönataktekniker måste distribueras kontinuerligt så att fler förstår konceptet bättre.

Det skulle vara intressant att göra ytterligare undersökningar och studera lagar och subventioner kopplade till gröna tak i Tyskland. Kan Sverige anta en liknande strategi? Det skulle dessutom vara användbart att samla in och sammanställa information om fysiska egenskaper hos alla tak i Malmö. Tak kan betraktas som utrymmen användbara inte bara för växtlighet utan också för solcellssystem eller vattenhållningssystem. Dessutom skulle det vara intressant att följa upp ifall de grönatakmetoder som analyserats i denna studie har implementerats och varit användbara i de valda studieområdena. (Less)
Please use this url to cite or link to this publication:
author
Rauhala, Malin LU
supervisor
organization
course
FMIL01 20191
year
type
M2 - Bachelor Degree
subject
keywords
Green roof, urban planning, environmental engineering, GIS, remote sensing, potential, green roof technology, gröna tak, stadsplanering
report number
LUTFD2/TFEM-19/5149--SE + (1-54)
ISSN
1102-3651
language
English
id
8998885
date added to LUP
2019-12-19 13:52:36
date last changed
2020-01-02 10:55:59
@misc{8998885,
  abstract     = {This study evaluates and compares four green roof methods with the purpose to calculate how many green roofs that potentially can be built on already existing buildings in a city. The methods concern the cities Braunschweig, Thessaloniki, Lisbon, and Lund. Geospatial Information Systems and remote sensing analysis are used as tools in all of the methods. Furthermore, this study observes the criteria that have been chosen in the methods and examines the possibility to create a similar method for Malmö in Sweden. Relevant stakeholders, with knowledge on green roof technology and urban planning, give their opinion in interviews. The future for green roofs in Malmö, and what hinders a faster expansion, is also discussed. 

Roof slope and available roof area are used as criteria in all of the four methods. Other criteria found useful are weather conditions like sunlight availability as well as waterproofing membrane layer and load-bearing capacity. The latter is very important to incorporate in the method since it highly affects the result. 

The evaluated green roof methods follow a very similar structure. Differences depend on the initial aims, the additional tools that were used, the available input data and the scenarios that were chosen. Only one of the methods includes a field study. However, it is concluded by some of the researchers that field studies and in-situ measurements should be added to their method to improve accuracy. A sensitivity -and uncertainty analysis should also be performed. Moreover, it can be convenient to use a drone to collect both remote images and detailed images of buildings.

The people interviewed in this study believe that the number of green roofs will eventually increase in Malmö. The answers also demonstrate that there should be enough input data to start to create a green roof method for Malmö. The respondents appear positive towards it. However, one of the most difficult parts would be to find the load-bearing capacities of all roofs. Moreover, at the moment there exist no political requirements or subsidies in Sweden, compared to Germany, that requires or promotes more green roofs to be built. Therefore, depending on the development of this matter, a green roof method may be of more interest in the future. However, one can also argue the opposite. If a green roof method was created and used in Malmö now, it could become an argument to implement supporting laws or subsidies to increase the number. 

Other things that may hinder a faster expansion of green roofs in Malmö are building permits, finances and a general lack of knowledge. Available information on green roof technology needs to be distributed continuously so that more people understand the concept better. 

It would be interesting to do further investigations and study the laws and subsidies connected to green roofs in Germany. Can Sweden adopt a similar approach? It would furthermore be useful to collect and compile information about the physical properties of all roofs in Malmö. Roofs can be considered as space for not only vegetation but also for solar cell systems or water retention systems. Moreover, it would be interesting to follow-up if the green roof methods analysed in this study have been implemented and been useful in the chosen study areas.},
  author       = {Rauhala, Malin},
  issn         = {1102-3651},
  keyword      = {Green roof,urban planning,environmental engineering,GIS,remote sensing,potential,green roof technology,gröna tak,stadsplanering},
  language     = {eng},
  note         = {Student Paper},
  title        = {Evaluation of methods for calculating the green roof potential on already existing buildings in urban areas.},
  year         = {2019},
}