🚁 Heli view: The greening of the third oldest profession

African construction work is projected to grow from $58 billion annually to $75 billion within five years. 

• This is driven in part by more than 570 mega projects jointly valued at $450 billion.

• Many are situated in Egypt, Nigeria and South Africa. 

• Expect more jobs, more homes, more growth. 

The catch: New steel & cement towers will also significantly strain the environment. 

• Steel and cement industries account for 38% of African greenhouse gases. 

• Building material emissions will rise from 3.5 to 4.6 Gt CO2eq/year by 2060. 

Dawning realisation: As Africa’s cities grow, they must directly incorporate climate action. Or their vibrancy and promise may falter. 

The underlying driver: Africa’s population will add 1.1 billion people by 2050, or 75% of the global growth. 

• The result is growing urbanisation. More than 40,000 people move to cities daily. 

• With ever more Africans in pursuit of new opportunities, the urban populace will double.

• Or more. Nairobi will likely grow from 5 million to 14 million inhabitants. 

Strain gain: The resulting construction boom means more emissions, sprawl and habitat loss.

• Estimates suggest 80% of the infrastructure needed by 2050 is yet to be built. 

• With more construction, the likely impact of extreme weather also rises.

• Floods and heatwaves will disproportionately affect populated areas. 

The key question: How can Africa mitigate the environmental impact, foster resilience and achieve eco-friendly urbanisation?

The solutions: By embracing green building practices in three ways: Changing building design, adopting new construction materials and integrating renewable energy.

Building design: Small tweaks could significantly improve outcomes. 

• Windows are the main culprits with heat loss or gain in buildings. 

• Developers can reduce air-con if they reconsider window-to-wall ratios.

• This in turn reduces energy use, especially if fossil fuel driven. 

A new look: The appearance of buildings may evolve. Change will be visible.

• Green roofs insulate buildings, absorb rainwater and create habitats for birds & insects. 

• Vertical gardens improve air quality and add a touch of nature.

• South Africa’s Fynbos building calls itself the first “biophilic living structure” on the continent. 

• Its “climate control is provided by natural layers. Exterior plantings have a cooling effect.” 

Construction materials: Replacing cement and its cousins is likely to be the biggest lever. 

• The green building materials market globally is expected to triple to $962 billion by 2033.

• Key is sourcing locally to reduce the need for energy-intense transport.

• Local replacement materials include adobe, laterite, termite mound soil, timber, stone, bamboo, sand and dry vegetation. 

• Revived techniques include rammed earth, sun-dried bricks, compressed earth blocks, wattle & daub, timber-framed construction, sandbag construction and thatched roofs.

Broad support: Jonathan Duwyn at UNEP says, “Locally adapted sustainable design, construction and materials coupled with renewables and innovation represent a great opportunity."

Integrating renewable energy: Without tackling power consumption, progress will be limited.

• By 2050, about 60% of Africans (1.4 billion people) will live in cities.

• They’ll consume about 3 times more electricity than rural residents.

No way round: Experts say wind or solar power generation should be added directly into buildings. 

• Facades, roofs and concourses are obvious places to install equipment.

• Landlords will see a second source of recurring income on top of rent. 

Prime example: The Sterling Bank Tower in Nigeria sports 3,250 high-efficiency crystalline silicon photovoltaic glass panels, spanning 6,500 sq metres over 17 floors.

• It’s the largest solar integration in Africa to date, providing 995 kWp to the tenants. 

The upside: Incorporating renewable energy into building design means addressing climate change as well as ensuring reliable electricity supply to an increasingly urbanised continent.