Proper use of public spaces saves energy

24Apr 2016
Guardian On Sunday
Proper use of public spaces saves energy

UN-Habitat charter defines public spaces as “all places publicly owned or of public use, accessible and enjoyable by all for free and without a profit motive.”

Dar es salaam botanical gardens

” They include both publicly and privately owned public spaces, though public ownership often guarantees more stable access and enjoyment over time.

Contrary to what is generally perceived, public spaces are categorized in into Multi-use Public Spaces that include avenues, boulevards, streets, squares, sidewalks, riverbanks and waterfronts, Public Open Spaces such as parks, gardens, playgrounds, public beaches and Public Urban Facilities consisting of public libraries, municipal markets, civic centres and the related facilities.

There is a very strong relationship between public spaces and economic gains. Clear evidence from various studies shows that a well-planned and well-managed public space has positive impact on the price of properties at a close neighbourhood.

In the Netherlands for instance, a park view raised house prices by 8 per cent, while in Berlin, proximity to playgrounds increased land value by 16 per cent.

This relationship between the two albeit in a narrower scope is quite familiar to many in the real estate business where commercial plots facing busy public streets are valued at a higher price compared to the ones at the back.

Unbeknownst to many however, public spaces are critical for environmental sustainability and energy use in a city if adequately planned and designed.

The green open spaces play a significant role in mitigation and adaptation strategies to climate change as they minimise carbon emissions by absorbing carbon from the atmosphere.

Studies show that 10 per cent improvement in a street-walk quality could yield a reduction of 15kg of carbon dioxide emissions per household per year as car reliance reduces in a city.

Contrary to that however, small open spaces that are used as car parks and the related activities paved with asphalt and other solar energy absorbent materials can have an opposite effect and contribute to what is termed as ‘urban heat island effect.’

Heat islands are formed as vegetation is replaced by asphalt and concrete roads, buildings and other structures that absorb, rather than reflect, heat from the sun, causing surface temperatures and overall ambient temperatures to rise.

Studies show that non-shaded asphalt parking lots can increase the surface air temperature for more than 30 degrees Centigrade.

The effect of this temperature rise is felt in the surrounding buildings in the form of cooling energy required. A single tree planted in a parking lot that provides shade can save the surrounding buildings hours of air-conditioning.

We should also note that green spaces may also act as sustainable drainage system due to their porous nature as well as solar temperature moderator by absorbing solar heat gains without emitting much of the heat absorbed. They act as a source of cooling corridors, wind shelter and wildlife habitat.

Many city governments are using planning and design to catalyse urban regeneration, create socially and culturally inclusive public places and promote greening of the city. Local and national governments are developing policies that promote compact, livable areas, with adequate public space that facilitate public transport, encourages walking and cycling, thereby reducing carbon emissions and energy demand.

While in the more developed countries and successful cities such as Barcelona and Brussels, the ratio of 50 per cent of public space is common where up to 35 per cent of the city area is allocated to street space and an additional 15 per cent for other public use, the situation in East African cities such as Dar es Salaam is extremely dire.

Cases where planned public open spaces have been used for private investments are quite common and have been persistent for a long time. What the society has failed to understand is the cost of these unregulated private investments to health, environment and energy bills.

The World Health Organisation (WHO) recommends a minimum of 9 square metres of green space per capita and that all residents live a 15-minute walk to a green space. That is to say over 40 million square metres (40,000sq. km) of green space is needed for the 4.5 million residents of Dar es Salaam.

We should be very scared that we are not even halfway in meeting that recommended target since studies have demonstrated that interaction with nature, through green public space, is associated with general and mental health. Other studies also suggest that urban ecosystem services like air pollution reduction and urban cooling have multiple long term health benefits.

Since open spaces serve as breathing points, a city with very few open spaces traps heat. The trapped heat is then transferred to the buildings leading to higher energy demand with apparent energy bills for indoor comfort.

Government should also note that higher energy demand is tantamount to higher demand for its production. In a country where electrification rate is less than 15 per cent of the total population we cannot afford a supply for an unnecessary demand in the urban centres while keeping the rural poor short of it.

Measures to use the available energy for consumption efficiently are as necessary as the efforts to increase its production. Measures such as building codes that are directed to individual constructors are as important as the government’s commitments.

The government through its Ministry of Lands, Housing and Human Settlement Development and the Ministry of Regional Administration and Local Government has the responsibility of managing the planned public spaces, making sure they are used for their intended purposes and making laws on public places planning in new developments.

We therefore ask the government to increase the number of green public spaces and take a different approach from that of the former Mayor of Ilala Municipality who scrapped all greenery in the streets roundabouts in the congested Central Business District (CBD) infamous for its environmental unfriendly glass buildings and concrete paves.

We do understand the challenge in maintaining the greenery in these places but we believe that a bigger effort coupled with Public Private Partnership (PPP) programmes can serve the purpose.

We also understand that the changes needed to create, revitalise, manage and maintain public space, including participatory processes to define their use might call for revision of laws and regulations but we also believe that there is always a way, given the will.
* Dr Fatma Mohamed is the National Project officer, Promoting Energy Efficiency in Buildings in East Africa, UN-Habitat. Email: [email protected]