How health and climate teams across Africa use Google’s Open Buildings data to improve society
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Health planners and climate analysts in Rwanda, Nigeria and South Africa are using Google’s Open Buildings dataset for frontline projects that close service gaps, improve lives and strengthen community resilience.
Created at Google Research Africa’s Accra lab, it converts high-resolution satellite imagery into the most complete public map of human settlement yet published. Each polygon represents an individual roof.
The dataset contains 1.8 billion building detections across an inference area of 58 million kilometres covering Africa, South Asia, South-East Asia, Latin America and the Caribbean. With it, analysts can estimate population, density and infrastructure needs without expensive field surveys.
Across the continent, artificial-intelligence (AI) tools are graduating from pilots to public-service workhorses, powering everything from crop-price forecasts to live language translation. Open Buildings has become part of that shift, proving that open, locally guided AI can turn sparse data into timely decisions without locking African problem-solvers behind paywalls or proprietary gates.
For example, in Rwanda, the Ministry of Health and Kigali-based Sand Technologies resited rural clinics with help from the dataset. Their new blueprint aims to bring 92% of citizens within a 30-minute reach of care, trimming journeys that put mothers and newborns at risk.
Read also: AI for Good: How Google is building AI solutions to global problems in Africa
By modelling how long patients need to reach care: on foot, motorcycle or road, the tool exposes healthcare deserts hidden by district averages.
Planners have already reshuffled proposed sites in two pilot provinces. Once built, the new network is expected to bring 92 % of Rwandans within half an hour of essential services, sharply reducing delays that endanger obstetric and newborn cases. The workflow is now being adapted for pharmacy and ambulance-based siting.
Across Northern Nigeria, epidemiologists at AFENET and geographers from WorldPop uncovered 10,250 buildings and helped vaccinators who reached 70% of the zero-dose and under-immunised children identified through the mapping in just six months.
Field teams verified 10,250 buildings in Yamma 2 ward of Katsina state, then guided outreach campaigns using the new coordinates.
In six months, vaccinators reached over 70% of children who had never received a single dose of DPT, measles or polio vaccine—cutting zero-dose pockets by up to 65 % in the targeted ward. All mapped settlements are now stored in the national database, so they remain on the radar for future health and nutrition programmes.
“Open Buildings gives us the roof-level detail to build accurate population grids where traditional data is missing. Overlaying those grids with vaccine-coverage maps lets our joint WorldPop–AFENET teams pinpoint zero-dose pockets and guide vaccinators street by street, so no child is missed”, Dr. C. Edson Utazi, Associate Professor of Spatial Data Science, WorldPop, University of Southampton, said.
Meanwhile, the World Resources Institute (WRI) has already applied this flood-risk modelling in Dire Dawa, Kigali, Musanze, Gqeberha and Johannesburg, combining two-dimensional hydraulic simulations with building footprints to create block-by-block exposure maps.
The need is pressing: Nairobi is still recovering from the May 2024 floods that displaced more than 278,000 residents, while Johannesburg’s rapid growth along the flood-prone Jukskei River continues to heighten vulnerability.
“This detailed data was instrumental in shaping our approach to fostering innovative nature-based solutions that will enhance Nairobi’s resilience and restore its vital river ecosystems”, Walter Samuel, Project Manager, Geo Analytics, World Resources Institute (WRI), explained.
These projects tackle challenges felt across the continent. Africa still has about 8.7 million “zero-dose” children who receive no routine vaccines each year, while the urban population is projected to almost double to nearly one billion people by 2035, forcing new homes into high-risk floodplains and informal settlements.
By giving ministries, city engineers and NGOs a street-level view of where communities are growing and how they change over time, the Open Buildings dataset lets limited budgets flow to the people and places that need them most.
“These projects show what happens when local expertise meets open, scalable technology: mothers reach clinics sooner, children receive long-overdue vaccines, and city planners get ahead of the next flood. We’re thrilled to stand beside partners who turn data into decisive action, proving that AI’s highest calling is to solve real-world challenges”, Dr Aisha Walcott-Bryant, Research Scientist & Head, Google Research Africa, says.
From problem to solution, see a summary of their impacts below:
| Sector & country | Key challenge | What local teams are doing | How Open Buildings helps | Measured impact |
| Health access – Rwanda | 30 % of citizens live >30 min from care | Provides a wall-to-wall map of every roof, so planners know the true settlement size and location | Urban resilience – Kigali, Johannesburg and 3 cities | New network design targets 92% of citizens within 30 min of care (pilot districts already approved) |
| Immunisation – Northern Nigeria | In northern Nigeria, health teams struggle to reach 2.1 million zero-dose children (Gavi) | AFENET & WorldPop used footprints to hunt unmapped villages, guiding vaccinators | Reveals 3,700 hidden settlements and growth hot-spots via the temporal layer | 78,000 previously unreached children vaccinated; wasted journeys down 40% |
| Urban resilience – Kigali, Johannesburg, and 3 cities | Floods displace hundreds of thousands; informal homes cluster on floodplains | World Resources Institute (WRI) overlays 2-D flood models on footprints to rank house-by-house risk | Gives engineers street-level exposure counts, even in informal areas | Nairobi pilot feeds early-warning zones; workflow now adopted for Johannesburg and four other cities |
From lifesaving clinics to climate-smart cities, these projects show how open AI is fast becoming Africa’s quiet engine for equitable progress.
