Building collapse has emerged as a persistent and critical challenge within Nigeria’s construction sector, with recurring incidents over the past decade resulting in significant loss of life, property damage, and erosion of public confidence in the built environment. These failures are not merely accidental but are largely symptomatic of systemic negligence embedded across the project delivery lifecycle. This study critically examines the impact of negligence on building construction in Nigeria, with particular emphasis on how the actions and inactions of key stakeholders, developers, contractors, design professionals, and regulatory authorities collectively contribute to structural failures. Negligence within the industry manifests through the widespread use of substandard materials, poor workmanship, inadequate site supervision, and persistent non-compliance with established building codes and specifications. Cost-cutting practices by developers and contractors often prioritise short-term financial gains over structural integrity, thereby introducing latent defects that compromise building performance. In parallel, insufficient professional diligence, particularly in design verification, construction monitoring, and quality control, allows critical errors to remain undetected until failure occurs. The study further identifies weak institutional and regulatory frameworks as a major enabler of negligence. Although statutory guidelines and building codes exist, their enforcement is frequently undermined by inadequate monitoring mechanisms, bureaucratic inefficiencies, and systemic corruption within approval and inspection processes. This regulatory gap facilitates the proliferation of unsafe structures that do not meet minimum safety standards. The consequences of building collapse extend beyond immediate physical destruction, encompassing economic dislocation, social instability, and reputational damage to the construction industry. These impacts ultimately hinder sustainable development and undermine the credibility of professional practice in Nigeria. This paper, therefore, advocates for a comprehensive and integrated response that includes stricter enforcement of regulatory standards, enhanced accountability mechanisms, continuous professional development, and the adoption of ethical best practices across all levels of project execution. Addressing negligence as a root cause through institutional reform, stakeholder responsibility, and improved governance structures is essential for mitigating building failures and promoting a safer, more resilient built environment in Nigeria.