‘Sustainable architectural designs will mitigate climate crisis’

There have been renewed calls to embrace and enforce new building designs that withstand intense climate conditions such as stronger winds, extreme heat, wildfires and unending rainfalls resulting in flooding.

Generally, buildings are a major contributor to global warming, but the roles of architects in the building sector are considered huge, and they have an impact on changing how buildings are designed to cope with extreme weather conditions and climate change impacts.

The building and construction sector is the largest emitter of greenhouse gases, accounting for 37 per cent of global emissions. Production and use of critical building ingredients and materials such as cement, steel, and aluminium have a significant carbon footprint. Also, demolition and new construction both come with carbon footprints.

Experts are canvassing for mitigating methods in building construction such as sustainable architecture and green building designs that will provide low-impact building materials that use less energy, natural light, rooftop solar panels, smart windows that block Ultraviolet (UV) rays, and advanced energy-efficient Heating, Ventilation, Air Conditioning (HVAC) systems.

The Guardian gathered that the use of green roofs helps improve buildings’ insulation, and remove heat from the air through evapotranspiration, while increasing vegetation helps reduce external surface temperatures of walls and paths through shading.

Furthermore, cool/white roofs that reduce the heat absorption of new buildings are increasingly being deployed to reduce climate change’s impact on buildings.

For flooding/sea level rise impacts on buildings particularly in flood-prone locations, modern design now integrates an effective stormwater management system through infiltration trenches, retention ponds, downstream flood control measures and standards for a base structure elevation with flood-proof materials.

For existing buildings, an effective strategy for reducing near- and mid-term carbon emissions includes deep energy retrofits in which architects retrofit such structures to meet high-performance standards.

There is also a need to reduce the use of the highest-emitting materials like concrete, steel, aluminium, and foam insulation through the design of new buildings. According to the experts, prioritising recyclable and sustainable materials, such as steel, and implementing waste-reduction strategies during construction will reduce the amount of waste sent to landfills. They also noted that buildings with improved indoor air quality, and natural light contribute to a more comfortable and healthier living environment.

However, there are challenges, which include logistical, educational and economic issues related to the initial costs of sustainable materials and technologies, careful planning, resource management and stakeholder coordination.

Industry professionals believe that keeping up with rapid advancements in green building technologies demands adaptation, and navigating the regulatory environment of sustainable construction has become crucial in changing weather.

A Professor of Architecture, Erekpitan Ola-Adisa, said the recent devastating floods in various parts of the country have highlighted infrastructure vulnerabilities, adding that innovative architectural solutions such as flood-resilient building designs can withstand nature’s wrath.

She urged architects, builders, and policymakers to prioritise designs that not only protect lives and property but also promote sustainability as flooding has become a recurrent challenge, particularly in the Niger Delta regions, urban centres like Lagos, and the hinterlands where river overflow and poor drainage exacerbate the situation.

Ola-Adisa said one of the most effective strategies in flood-resilient architecture is elevating buildings above potential flood levels as seen in informal settlements like Makoko, Lagos, where structures are built on stilts to allow water to flow underneath.

However, in more formal settlements, she said residential clients often shy away from such designs, fearing the cost and practicality, leading to issues like sinking buildings when proper elevation is neglected.

“Utilising locally sourced materials is key to creating flood-resilient buildings, while high-quality concrete, treated with waterproof additives, can enhance durability.

“Natural materials like bamboo and hard or semi-hardwoods such as Iroko are sustainable and culturally relevant, promoting local economies,” she said. Ola-Adisa pointed out that flood-resilient buildings should also incorporate community input and emergency preparedness strategies, adding that designing multi-purpose spaces that serve as community shelters during disasters fosters resilience and social cohesion. She explained that engaging local communities in planning and building processes ensures that structures meet their unique needs and cultural preferences.

The architect also advocated investment in flood-resilient architecture, which protects the people, preserves the environment, and strengthens the economy. The Managing Partner, Sowunmi Williams and Associates, an architectural firm, Mr Sowunmi Williams, corroborated Ola-Adisa’s views, pointing out that the architectural response to flood-prone areas should be through architectural design, where the buildings will always be above water levels in situations of flooding or sea level rise.

According to him, the roof is the major element in a building that is exposed to solar radiation, it is advisable to have a long roofing projection that covers the external walls, and shades them from different polar radiations.

He added, “Once the shade is there, it means the walls will not receive solar radiation and can’t absorb heat. It makes the external walls not absorb heat easily in the era of climate change.

“Roofing materials particularly in our tropical region must be roofed with insulation to prevent the transmission of solar radiation absorbed by roofing elements from transmitting into the interior space. These strategies will create a thermally comfortable environment for space users.

The generally acceptable standard for room temperature is between 24 to 27 degrees Celsius. Still, the challenge is that the outside temperature in Abuja is about 38 to 40 degree Celsius depending on the day whereas in Lagos is 30 to 35 degree Celsius depending on the month of the year. The earth’s temperature is generally above the room temperature. That’s why strategies must be deployed collectively in building design to mitigate climate impacts.”