The first step in a renovation decision is to understand what is already there. Review available drawings, maintenance records, previous alterations, structural condition, building services, fire safety, accessibility, and hazardous materials where relevant. Commission surveys and investigations to verify assumptions. Hidden defects can materially change the scope and cost of renovation, while a sound existing structure may offer a valuable foundation for reuse. Decisions should be based on evidence rather than the visible condition of finishes alone.

Write down the spaces, capacity, performance, appearance, and operational requirements the future building must meet. Determine whether the existing layout can be adapted or whether structural limitations prevent the required changes. Renovation may preserve useful fabric and reduce demolition, but it can involve complex interfaces and compromises. New construction may provide greater freedom to optimise layout and services, though it usually requires more extensive site work and approvals.

Prepare estimates for both routes using the same scope and quality assumptions. Renovation budgets should include surveys, enabling works, protection, temporary services, unknown conditions, phased access, and making good. New-build budgets should include demolition where required, site preparation, new infrastructure, and the full construction scope.

Compare the programme as well as the cost. Occupied renovations may need careful phasing to keep people or operations safe while work continues. Planning rules, heritage status, site boundaries, height limits, fire requirements, accessibility, energy standards, and utility capacity can influence which option is possible. Renovation may be constrained by existing geometry or protected features. A new building may trigger different planning and infrastructure obligations.

Engage relevant authorities and technical advisers early so the team understands approval routes and identifies conditions that may affect the design. Retaining an existing structure can avoid some demolition waste and the impacts associated with producing new structural materials. However, an inefficient building may require significant upgrades to meet future energy and comfort expectations. New construction can be designed for modern performance, but it also carries impacts from new materials and site activity. Compare realistic whole-life outcomes, including energy use, maintenance, adaptability, and future replacement needs.

The right answer is specific to the building, site, budget, and intended use. A feasibility study should compare technical risks, approvals, cost, programme, disruption, environmental impact, and operational performance. Include contingency where uncertainty remains and identify information needed before a final commitment. Renovation is not automatically cheaper, and rebuilding is not automatically better. A structured comparison helps owners choose a route that is practical today and remains valuable over the long term.