This study develops an innovative model for assessing the environmental impact of office buildings during the Operation and Maintenance (O&M) phase, which remains largely overlooked in decarbonisation efforts. Building on the Ecological Footprint methodology, it proposes a Workplace Integrated Ecological Footprint Assessment (WIEFA) model, that links operational data, user actions and spatial occupation to support evidence-based decision-making for corporate real estate managers and other stakeholders. This study aims to capture how people’s presence and everyday choices influence environmental performance and to provide a multidimensional tool that aligns corporate asset strategies with sustainability goals.
The research adopts a three year participatory action research approach involving property companies, investors, workplace and facility managers, HR professionals and office users. Through iterative co-design, testing and refinement, WIEFA conceptualises the office as a semi-closed system encompassing three impact categories (i.e. site, building and users). Across subsequent development phases, the WIEFA model was finally tested across eight office buildings differing in size, typology, certification level, workplace arrangement and accessibility. WIEFA aggregates eight impact sources − built-up, energy consumption, water consumption, material consumption, mobility, food and drink, waste generation and trade-off potential − into a unified metric expressed in global hectares (gha), and allows result reporting in multiple units of measurement (gha/occupant, gha/employee, gha/m² and “football fields”).
Results show that WIEFA can complement existing sustainability assessment protocols by capturing the dynamic relationship between building characteristics, spatial occupation and user behaviour during O&M. Across the case studies, people’s choices − especially regarding mobility, food consumption, presence in the office and waste generation − significantly shape total environmental impact, often more than building age, certification or workspace arrangement. Moreover, technological upgrades alone do not guarantee lower impact if occupancy and user practices remain unchanged. The tool enables CREM professionals to identify inefficiencies, compare assets and understand how flexible work models influence environmental performance.
This study advances a people-centred, operationally grounded approach to environmental impact assessment in CREM. WIEFA overcomes the limitations of existing protocols by integrating user presence and actions into environmental accounting, offering a unified and tangible metric and providing flexible outputs suitable for different stakeholders − including office users. The model establishes a foundation for continuous monitoring of environmental performance and supports the alignment of workplace strategies, organisational policies and sustainability objectives in flexible work contexts. It also prepares the ground for future research towards a dynamic tool integrating well-being, comfort, governance and long-term effects of remote versus on-site work.
