When people hear the term “green building”, they often imagine expensive technologies, costly developments or environmentally friendly features that only wealthy buyers can afford.

But green buildings do not have to be luxury log homes surrounded by lush vegetation. A green building can be any size. It is one that is designed, built or upgraded to use water, energy and other resources in a way that causes less harm to the environment.

For example, a green building would use natural light and ventilation to reduce the need for electric lighting, air conditioning and fans. It could be built with more sustainable materials, like recycled steel, reclaimed wood, locally made bricks or low-carbon concrete.

Indoor spaces in green buildings are designed to be comfortable and reduce running costs over the building’s lifetime. Good insulation, energy-efficient lighting, solar panels and systems that collect rainwater can achieve this.

We are sustainable housing researchers who’ve spent years researching how green housing has evolved. In a recent study, we tracked the growth of green building certification in South Africa. We looked at 510 buildings that received green certificates between 2011 and 2023.

Our analysis included where they were located, who owned them and the ratings they received. We also looked into whether the certification system stops developers from making misleading claims about how green a building is.

Our research found that green building is growing and spreading across South Africa. However, it is mainly happening in Johannesburg, Cape Town and Sandton. This is largely through upgrades to existing buildings rather than new green buildings, showing that green feature upgrades add value to older properties.

Most buildings received only mid-level green ratings, however. The highest rating for green buildings – six stars – is quite rare.

Some buildings received very low ratings, which means that “greenwashing” (pretending to be green) might be happening.

The next step is to establish how much value green upgrades and certification can add to South Africa’s existing properties.

How buildings get a green rating

It costs different amounts to get certified, depending on the building. A green building rating measures how well a building saves energy, water and other resources, and reduces carbon emissions and environmental harm.

South Africa’s Green Star system, introduced in 2008, rates new and existing buildings, interiors and neighbourhood developments. This system was developed by the Green Building Council South Africa. It sets up a common standard for developers, investors, financiers, owners and occupants to judge how environmentally friendly all buildings are.

In South Africa, it’s not compulsory for new buildings to be green. It’s up to investors, developers, building owners and users to opt for green building or not. This is similar to the situation in many developing countries, where including green features in housing developments remains voluntary rather than compulsory.

But voluntary does not mean unimportant. Green buildings are increasingly attractive because they can reduce resource consumption and improve energy and water efficiency.

They also appeal to buyers as they feature quality and sustainability. Green buildings can have improved indoor air quality, lighting and other measures. They are improved through passive design – the direction a building faces, the size and placement of its windows, and the use of suitable building materials to make the most of natural light and airflow while keeping indoor temperatures comfortable.

Without rating systems and certification, it can be difficult for consumers and investors to tell if a building genuinely reduces the impact on the environment or is just claiming to do so.

Green building certification is growing rapidly in South Africa

Our study found that there has been a huge jump of 1,694% from about 50 to over 897 green buildings certified in South Africa between 2014 and 2024. This suggests increasing market interest in sustainable buildings. Green development is becoming more established within the property sector.

The banking and commercial property investment sectors are actively adopting green building practices in South Africa, we found, driven by strong financial, retail and office markets. Educational institutions are also becoming early adopters. There’s increasing demand for green buildings in student residences and tertiary education facilities.

For developers and property owners, certification can offer several advantages: increased rental and capital value, with tenants, investors and buyers putting sustainability first when deciding where to live.

Certification can also help property owners qualify for green financing, especially with banks and development finance institutions investing more in environmentally responsible projects.

The problems with green certificates

Apart from benefits, there are also challenges. One concern is greenwashing, where buildings are marketed as environmentally friendly without delivering meaningful environmental improvements.

Greenwashing happens when developers exaggerate a building’s environmental benefits to attract buyers, investors and tenants.

Our study found warning signs of this. Most certified buildings met the four-star “best practice” standard, but six-star ratings – awarded for “world leadership” – were rare. Some existing buildings also received ratings below four stars.

As certification becomes more popular, building owners, investors and regulators need to check that it reflects real improvements in energy use, water use and environmental impact, and is not just being used as a marketing tool.

What needs to happen next

Encouragingly, we found that green building certification is starting to spread beyond South Africa’s largest cities. This could make greener building practices more practical and accessible in other parts of the country.

Builders, developers and homeowners may still wonder whether going green is affordable and worthwhile. A useful first step is to ask a suitably qualified building professional how much green features would cost and how much they could save over the building’s lifetime. These features can be included in a new design or added to an existing building.

Green certification could help reduce energy and water use, improve building practices and make it easier to qualify for green financing. But it must lead to real environmental improvements. As certification grows, government, investors and buyers need to ask: are these buildings genuinely becoming greener, or do they simply have a green label?

Expert insights provided by Jonathan Oladeji, Postdoctoral Research Fellow, University of Johannesburg, and Chioma Okoro, Professor and Acting Head of Department: Department of Finance and Investment Management, University of Johannesburg. This article was originally posted on theconversation.com and is republished here under a Creative Commons license. Read the original article here.