PURPOSE Because of the sort of working environment and the nature of construction jobs, a high rate of poor mental health has been recorded in the construction industry. The aim of this study is to compare construction workers' mental health before and during the COVID-19 pandemic in Nigeria.
DESIGN/METHODOLOGY/APPROACH A survey questionnaire was developed and administered online to building environment professionals working on construction sites. Data were analysed using descriptive statistics such as mean and standard deviation. An independent sample t-test was also conducted to determine whether there was a significant difference in the mean before and during the COVID-19 infection.
FINDINGS The results show that mental health challenges were more prevalent during the COVID-19 pandemic compared to before the pandemic. The result of the independent sample t-test revealed that there exists a significant difference in all the mean before and during COVID-19 except sleeping too much or too little; having low or no energy and lack of emotion that shows no significant difference.
ORIGINALITY/VALUE This study is the first to compare the mental health of construction workers before and during COVID-19 in Nigeria. The significance of this study was that it would provide an insight for construction managers and other decision-makers on the most critical mental health challenges on construction sites, which will help in an attempt to improve the mental well-being of construction workers.