Inefficient buildings are draining billions from the economy, and every household with a poorly built home is paying the price month after month, a new report has revealed.

The Kenya National Building and Construction Decarbonization Roadmap, developed by the Global Buildings Performance Network (GBPN) and partners from government, industry, academia and civil society, warns that a typical Kenyan family spends about $55 (Sh7,095) a month on electricity.

In an energy-efficient home, the report says, the bill drops to $30 (Sh3,870). The $25 (Sh3,225) monthly gap adds up to $300 (Sh38,700) a year, enough to pay half a child’s annual school fees.

Multiply that loss across millions of homes, the report notes, and the national cost runs into billions.

“These losses are rarely visible in a single budget line. They emerge as higher energy bills, increased fuel imports, costly retrofits, and infrastructure investments that could have been avoided,” says Mugure Njendu, Africa Programs Development Lead at GBPN.

The roadmap, due for launch in Nairobi later this month, identifies buildings and construction as responsible for 32 per cent of Kenya’s carbon emissions, according to the report.

Making matters worse, it says, 80 per cent of construction in the country happens informally, largely beyond the reach of any regulator.

The roadmap sets an emissions target of 8.8 million tonnes of carbon dioxide equivalent (tCO2e) by 2030 and projects a 60 per cent reduction in emissions by 2040 if its recommendations are followed.

It supports Kenya’s Nationally Determined Contributions (NDCs), the country’s climate commitments under the Paris Agreement.

At the heart of the problem, the report says, is how buildings are designed. Mumbua Musyimi, Kenya Project Manager at GBPN, says builders routinely ignore passive design, the basic decisions about how a structure faces the sun, channels a breeze and uses natural light.

“When buildings don’t manage heat, airflow, and natural daylight properly, they end up depending on mechanical systems just to function. Energy then becomes a recurring and growing operating expense,” says Musyimi.

Outdated plumbing, leaking pipes and water-heavy fixtures push costs even higher, she adds.

“These pressures strain already stretched systems, and the higher costs are usually passed on to the people living and working in the buildings,” Musyimi notes.

Kenya’s urbanisation rate runs at 4.4 per cent per annum, and the country faces a housing deficit of over two million units.

Construction is booming under the government’s Affordable Housing Programme, yet the report says most new buildings simply copy the flaws of older ones.

“Design decisions on orientation, materials, ventilation, and housing density often favour speed and upfront cost over long-term performance. Once these buildings are constructed, those inefficiencies are effectively locked in. Retrofitting for energy or water efficiency later is far more expensive than getting it right during construction,” says Njendu.

Rules are on the books but are rarely enforced, the report observes. The National Building Code (NBC) 2024 and the Energy (Solar Water Heating) Regulations of 2012 exist, yet compliance is weak, oversight is split between national and county agencies, and technical capacity on the ground remains thin.

The consequences reach further than energy bills, according to the report, with poor-performing buildings losing value faster, increasing default risks on mortgages, failing energy audits and struggling to access financing and insurance in an era where green credentials increasingly determine who gets funded and who does not.

“Amid rapid urbanisation and rising fiscal pressures, inefficient buildings are no longer tenable and present a liability to the country’s economic productivity, energy security, and long-term public expenditure,” Njendu observes.

GBPN is now building a coalition to close the financing gap that stands between the roadmap’s targets and real-world action, seeking to mobilise public, private and philanthropic capital, the report says.