One message came through loud and clear when we asked people for their ideas on creating sustainable cities: we need to make better use of the resources we already have.
As programme partner for Green Sky Thinking Week, Mott MacDonald has canvassed ideas from attendees at the Ecobuild exhibition; from our Twitter followers; and from a selection of our own experts. We posed 14 questions that covered many of the most pressing environmental, social and economic sustainability issues facing cities.
Among the diverse suggestions we received, the biggest theme that emerged was avoiding wasted resources. This is, of course, a major area of opportunity in the energy sector, and our respondents suggested renewable generation solutions including energy-from-waste, hydrogen fuel and solar technology. There are also opportunities for demand-side management (DSM) to reduce pressure on peak electricity generation capacity, which is increasingly of concern for many cities.
For the domestic sector this could mean the introduction of automatic controls to align domestic appliances’ use with peak output of any locally installed photovoltaic panels. In business, corporates could introduce DSM of non-essential services such as comfort cooling, meaning these are temporarily switched off during times of peak power load.
Waste can also be minimised in water and heat systems. Ideas submitted to us included harvesting rainwater and greywater, such as through recycling showers, using aerated shower heads and composting toilets to save water. Passivhaus design principles could reduce heat loss and capture passive solar energy, although the parallel issue of overheating and the ability to keep cool must be considered. It was suggested that homes with fuel cells could use the heat by-product for water and space heating. Furthermore, ground source energy storage could enable excess heat to be banked for when it’s needed.
On an urban scale, space is one of the most underused resources, and our respondents had plenty of ideas to rectify this. Some respondents advocated using tax incentives to encourage developers to retrofit existing buildings, and to persuade landowners to open up empty plots as public spaces. Vacant offices could be converted for residential use, and dilapidated streetscapes could be restored with simple measures such as painting. Roofs could, it was suggested, host vegetable gardens or become base slabs for residential structures.
All of these ideas evoke the concept of a circular economy. Under this model, everything has further use beyond its initial ‘life’, and waste is virtually eliminated by minimised consumption and a 'closed loop' of reuse and recycling. Society’s expectations must shift toward this way of thinking in all areas of life in order to create truly sustainable cities.
Other themes came through strongly in our idea-sharing project. It was clear that people wanted to see effective public transport at the heart of urban life, and journeys becoming fewer and briefer to improve citizens’ work-life-health balance. Journeys can be minimised by a compact city layout, with public facilities close to homes. Indeed, our staff have first-hand experience of how modern communications technology, such as the Lync system used in our offices, can reduce the need for business travel.
Where journeys must be made, our respondents suggested giving walking and cycling routes spatial priority, and making other sustainable transport modes as convenient as possible. Roads should be designed and constructed sustainably and inner-city housing pressure should be relieved by transport links to suburban areas.
Green spaces were another favoured topic, particularly for their contribution to sustainable drainage and flood mitigation, as well as their mitigating effect on the Urban Heat Island effect and the benefits of having spaces that belong to the community to encourage a spirit of cohesion and a sense of place. Trees were further advocated for providing shading and cooling and breaking up wind tunnels between buildings, helping to combat extreme weather at both ends of the spectrum – together with their naturally beneficial effects on air quality and biodiversity.
Finally, our respondents recognised that local buy-in was crucial to effecting change. Volunteerism by residents could make a large contribution through community projects, while appealing to investors is essential for large-scale improvements.
Our survey shows that the people communicating with Mott MacDonald, as well as our own experts, are passionate about good ideas to make cities better and help to create a circular economy culture. By implementing these ideas we will not only fulfil our environmental responsibilities, but bring lasting benefits to city residents, businesses and communities.