Older buildings usually consume more energy in operation than new construction. That is not only a cost issue. It also affects how an asset performs against market standards like BREEAM, EU Taxonomy, and CRREM, as well as regulations such as the Energy Performance of Buildings Directive and the rules for Building Automation and Control Systems (BACS). Many owners assume the only way to close the gap is a major refurbishment. Better insulation and new equipment certainly help, but they are expensive and disruptive. Investments in deep fabric and equipment upgrades can reach one to five percent of the asset value.