A surge in energy demand driven by the growing number of buildings and insufficient attention to sustainable and optimised energy-saving procedures are likely to threaten the economy and the environment. The building envelope is a significant component that influences energy requirements, directly affecting the operations costs. Thus, the current study considers the envelope to optimise the building�s Life Cycle Costing (LCC) and enhance energy efficiency. Therefore, to achieve the aim of the study, Building Information Modelling (BIM) with the integration of Life Cycle Cost Analysis (LCCA) is adopted to assess the building envelope and optimise energy use and relevant costs. Three alternatives of wall system: brick wall with rockwool insulation, brick wall with polystyrene insulation and curtain walls system, are considered for the building envelope to enhance energy-saving potential by analysing and comparing the energy demand. To determine LCCA, the Net Present Value (NPV) approach was adopted for the initial expenditure and the associated future costs. It was found that utilising insulation material with low thermal conductivity reduces heating and cooling energy resulting optimised LCC. Compared to curtain walls, the results show that the rockwool insulated wall reduces 17 of energy demand while the polystyrene wall reduces 12.7 of the energy. Similarly, rockwool insulated walls save 5 energy relative to the wall system with polystyrene insulation. Thus, integrating LCCA with the BIM approach at the conceptual design stages promotes energy and LCC optimisation. © The Author(s), under exclusive licence to Springer Nature B.V. 2023.