The government is reviewing its building code as part of efforts to promote sustainable urbanisation, with green construction, rainwater harvesting and efficient use of natural resources among the issues being considered. The Rwanda Housing Authority (RHA) expects to complete the technical review of the 2019 Rwanda Building Code before the end of 2026, according to its Director General, Alphonse Rukaburandekwe. ALSO READ: Northern Province: Governor urges better rainwater harvesting to combat floods Rukaburandekwe said the review is part of broader efforts to promote green and sustainable urban development, adding that several requirements related to environmental sustainability are already included in the current building framework. “Rainwater harvesting is one of the mandatory items that have to be applicable to all buildings,” he told The New Times. The 2019 Green Building Minimum Compliance System makes rainwater harvesting a mandatory indicator. The requirement is intended to reduce demand for potable water and help manage stormwater runoff by requiring buildings to capture water from their roofs. Rainwater harvesting at design stage Rukaburandekwe said rainwater harvesting is assessed during the technical verification process before a building permit is issued. The assessment begins at the design stage, looking at the building’s roof and catchment area, as well as the system for collecting, storing and using the harvested water. It considers factors including the location and capacity of storage tanks, gutters, downpipes and water-flow systems. Developers are also required to provide calculations showing the amount of water that can be harvested and a system schematic indicating the catchment area, piping and storage tank. RHA can use the building design to estimate its potential “harvestable water volume” and assess how the water will be used. For example, harvested water can be used for flushing toilets, irrigation and landscaping, depending on the design of the system. The assessment can also determine the period for which the stored water can provide supply to the building, based on the size of the storage facility and the building’s needs. The existing national standard on rainwater harvesting covers systems used for purposes such as toilet flushing and garden watering, where potable water quality is not required. ALSO READ: A peek at Kigali’s green buildings Green building compliance Rainwater harvesting is part of the wider Green Building Minimum Compliance System, which was introduced alongside the 2019 building code. The system uses a point-based framework covering indicators related to energy and water efficiency, environmental protection, indoor environmental quality and other green features. Rukaburandekwe said the assessment looks at how buildings use natural resources and incorporate measures that improve environmental performance. Examples include the use of solar energy, adequate ventilation and other measures designed to improve the efficiency and sustainability of buildings. “Usually we check how this building responds to, let's say, do they have, for example, solar panels? How is the ventilation within this building?” he said. Under the 2019 framework, the Green Building Minimum Compliance System is mandatory for new Category 4 and 5 buildings, while compliance is voluntary for other categories. Category 4 includes major buildings such as larger commercial, institutional, public and multi-storey developments, while Category 5 covers the most complex or high-risk structures, including buildings with specialised uses or significant structural, fire or public-safety considerations. Because these buildings have greater potential environmental and public-safety impacts, the Green Building Minimum Compliance System is mandatory for new Category 4 and 5 developments, unlike lower categories where compliance is generally voluntary. The system contains 29 indicators, with mandatory and optional indicators contributing to a minimum compliance score. The indicators cover areas including ventilation, daylighting, renewable energy, water-efficient plumbing fixtures and wastewater treatment. The framework therefore goes beyond rainwater harvesting, with the broader objective of improving resource efficiency and environmental performance in buildings. Building coverage and stormwater runoff RHA’s technical assessment also considers how developments occupy their plots, including building coverage, setbacks and the amount of space left around buildings. Rukaburandekwe said the authority checks whether proposed developments comply with the applicable master plan and setback requirements, including the proportion of a plot that is covered by a building. The assessment also looks at the surfaces surrounding buildings, including hard and soft landscaping. This is important for stormwater management because large areas covered by impermeable surfaces such as concrete and tiles can increase surface runoff during rainfall. The authority therefore considers how a development’s design and surrounding surfaces could affect the movement and management of rainwater. Rukaburandekwe did not specify any new requirements on green building or rainwater harvesting that would result from the ongoing review. The technical review is expected to be completed before the end of 2026. The revised code will then undergo further government processes before it is submitted to Parliament.
