Cost-effective retrofit packages for low-middle income residential buildings in Nigeria

Access to energy services is a major challenge facing Nigeria because energy is fundamental to poverty eradication and sustainable development. 60% to 70% of the Nigerian population have little or no access to electricity. Electricity is produced primarily from hydro and thermal sources, yet the demand outweighs the output. The shortfalls in electricity production and distribution in residential buildings are the reason behind the off-grid power generation by people in Nigeria. The use of off-grid power generators in Nigeria represents 84% of total urban households that depends on gasoline or diesel-powered generator for electricity supply with the rest living without electricity. Fuel combustion of such generators produces poor indoor air quality and emits greenhouse gas emissions. More so, recent dwellings condition survey suggests that most of the houses in Lagos are energy inefficient. The low-and-middle income households accounts for 88.9% and 9.3% of the total urban households of Lagos, Nigeria, respectively. This thesis aims to create cost-effective retrofit Packages for low-and-middle income buildings in Lagos, Nigeria to enhance thermal performance of the buildings, and improve the quality of life of the occupants to fill the gap in knowledge identified in research. By achieving this aim, energy insecurity will be mitigated, and CO2 emissions reduced. To achieve this aim, a mixed method approach was employed, exploring both quantitative and qualitative research methods. A pilot survey and scoping study was conducted between 2017 and 2018, respectively. During which statistical data were obtained from various organisations in Nigeria, as well as semi-structured interviews with various stakeholders. The main survey of this research occurred in the hottest period of March 2019 and involved 39 low-middle-income dwellings statistically distributed across the two political constituency of Agege, Lagos Nigeria. The data collected was both objective and subjective, this was supported by semi-structured interviews, measurements, observations, and walk-through audit. The data was analysed using Microsoft Excel, descriptive analysis, content analysis, dynamic thermal simulation (DTS). DesignBuilder software was used for the DTS, the software was calibrated using case study buildings. Two of the 39 existing building from each class of the low-and-middle income buildings were investigated using building simulation to compare their thermal performances. The economic feasibility of the retrofit packages was then assessed for the buildings under investigation. The results showed that the integrated cost-effective retrofit Packages to the low-middle-income buildings attained significant reduction in operative temperature of between 2oC to 4oC across retrofit Packages when compared to the reference building, between 28.9% and 38.5% reduction on the energy usage, and a reduction in cooling loads was between 63.2% and 68.2%. Consequently, the cost implications of the retrofit packages were assessed, the packages of each model were then ranked according to their thermal efficiency and economic feasibility to produce retrofit Packages for each of the building types. The homeowners, architects, builders, and all stakeholders can then select the Package that best fit the thermal needs and the budget requirement of the targeted income class. Several limitations and recommendations are therefore presented to give opportunity for future research.