The effects of climate change - in particular, the increasing heat stress and heavy rainfall events - pose significant challenges to cities, which will only increase in the future. In the development of sustainable new urban districts, the right course must already be set today in order to be able to cope with these effects and contribute to climate protection over the long-term.
In the context of urban development, increasing the quality of life in the built environment, improving thermal comfort and optimized climate resilience, green roofs offer interesting perspectives. Measures such as a low degree of land sealing, tree plantings, shading, rainwater management, high degree of greening, roof and facade greenery can contribute to the improvement of the urban microclimate. Moreover, it allows sustaining and increasing biodiversity, improve building performance and develop urban agriculture. Due to the limited use of pesticides in an urban area, honey harvested from urban beehives, can be healthier than from rural bee populations.
Between 2017 and 2020, almost 85 000 m2 of photovoltaic panels will be installed on the roofs of public buildings. These panels contribute to meeting one of the climate targets of the Brussels metropolitan area: double the production of renewable energy between 2017 and 2020. Green roofs and photovoltaics are not mutually exclusive.
There are many good reasons to combine photovoltaic and greening: e.g. to enhance building performance through cooling effects.
The focus of this challenge is therefore not the question "green or solar?", but "How to promote green solar roofs and facades in Brussels…with ambitious confidence?".
Proposals to address the following questions are welcomed:
- How to optimise the design of an all-inclusive planning and implementation process for green solar roofs and facades?
- How to develop a successful, all-inclusive planning process?
- Which analyses, standardised approaches and metrics are required at the different levels of an optimised planning process? We propose to consider three levels: urban planning - building design/architecture - implementation/operation
- Which method is best suited to assess the effect green solar roofs on the urban climate, quality of air, and GHG emission reductions, at individual and city level?
- How to enhance and develop the knowledge of the actors and stakeholders involved (e.g. measures for knowledge exchange)?
- How to identify factors of correct planning and implementation early on in the process, and how to carry them through in into the implementation phase?
- How to facilitate multi-disciplinary exchange towards a common planning goal?
- Which methods help the prioritisation and combination of the different functions of green solar roofs such as developing a favourable urban microclimate, energy production, improved biodiversity, quality of living for residents…) and avoid disappointment and conflicting expectations?
- Which stakeholders have to come together from the outset end and how to establish a fertile cooperation? Among the stakeholders to consider we propose urban planning, energy suppliers, planning authorities, water management authorities, urban design authorities, landscape architecture, property developers, insurance companies and financiers/banks, property managers, users/residents, professional gardeners involved in maintenance and care, apiculture experts, botanists
- How can the economic yield of green solar roofs be optimised?
- Which cost efficiencies are feasible for PV modules on green roofs or facades (conservative, bold approaches)?
- How can the costs and effort of maintenance of green solar roofs be minimised?
- What is the best approach to transparently allocate costs?
- What is the best strategy to exchange individual PV modules to avoid dismantling the whole system or to damage the greenery;
- Which are the legal, technical and ecological system boundaries of green solar roofs?
- What business models could be developed to promote the introduction of green solar roofs, to support climate roof installation or management company?
- Several companies offer technical solutions for the installation, implementation and maintenance of green solar roofs. The focus is primarily on the all-inclusive process from planning to operation in view of promoting the take-off of green solar roofs in Brussels.
- The result of the challenge should be a planning app and/or guideline for real estate developers, contractors and urban planners as companies such as energy supply and gardening companies.
Technical or design solutions should be limited to those that address the two questions