The dearth of green standards (GS) in sub-Saharan Africa is alarming and the green cost premiums (GCP) in seeking certification in emerging markets are scanty. This paper studied the Building Energy-Efficiency Code of Nigeria (BEEC) and estimated the potential GCPs associated with the various energy-efficiency ratings.
The study retrofitted 150 conventional residential bungalow and maisonette buildings using BEEC's energy-efficiency interventions and performed analytical estimating of the retrofitted designs. The mean cost premium associated with each energy-efficiency intervention is presented as well as their financial benefits and payback periods. The benefits are achievable financial-savings due to a reduction in energy consumption and savings in electricity payment estimated from the average energy demands of each building. An independent t-test was further conducted to determine the cost differential between energy-efficient design (ED) and conventional design over a five-year period.
The potential GCPs and their payback periods are actually less than feared. The study showed that less than 5% and 21% extra funding would be required to achieve 1 to 4-Star and 5-Star energy-efficiency ratings involving passive design interventions and photovoltaic systems. Passive and active design interventions produced a financial savings of $8.08/m2 in electricity payment and $2.84/m2 per annum in energy consumption reduction. The financial-savings ($10.92/m2) was objective to pay-off the GCPs in less than four years. The independent t-test analysis showed the cost of ED is more economical after four years into the project lifecycle.
The research provides cost benchmarks for navigating cost planning and budgetary decisions during ED implementation and births a departure point for advancing energy-efficient construction in developing markets from the rational economic decision perspective.
