Giving a two-decade-old building a smart future

Why existing buildings hold the key to faster carbon cuts

A twenty-year-old commercial building in Malaysia is being fitted with smart controls and data systems to cut cooling energy and carbon emissions. The project matters because it illustrates a principle now backed by two decades of research. Retrofitting existing buildings typically delivers faster, cheaper carbon reductions than demolition and rebuild.

For UK businesses, the logic is the same. Most commercial property was built before modern energy standards existed. Replacing those buildings wastes the carbon already embedded in their structure. Meanwhile, deep retrofits can cut operational emissions by 30% to 50% or more, according to the World Economic Forum.

The Malaysia project focuses heavily on cooling efficiency. That reflects a universal challenge. Heating, ventilation and air conditioning systems account for a large share of building energy use. However, many existing systems run inefficiently because of poor controls, fixed schedules or outdated setpoints. Optimising those systems through better data and smarter management can deliver significant savings without replacing major equipment.

This approach is gaining traction in the UK as well. Property owners face growing pressure to improve energy performance. Regulatory requirements are tightening. Tenants increasingly expect low-carbon buildings. Furthermore, retrofit projects preserve the embodied carbon already invested in a structure while simultaneously reducing ongoing energy costs.

How retrofit compares to demolition for carbon impact

Demolishing a building and constructing a replacement generates substantial carbon emissions. The process destroys the embodied carbon locked in the original structure. That embodied carbon represents all the energy and emissions associated with manufacturing materials, transporting them and assembling the building.

Research cited by the American Institute of Architects and RMI shows that reusing and retrofitting existing buildings can avoid 50% to 75% of embodied carbon emissions compared with new construction. Those figures come from lifecycle carbon assessments that compare whole-building scenarios over several decades.

Historic England has published similar findings for UK buildings. Their research shows that retrofitting historic and traditional buildings can cut operational emissions by over 60% in many cases. Some residential case studies have achieved reductions as high as 84%, depending on the building type and the measures applied.

The carbon savings from retrofit are immediate. A new building must operate for many years before its lower running emissions offset the embodied carbon released during construction. In contrast, a retrofitted building preserves its existing embodied carbon while cutting operational emissions from day one.

Consequently, retrofit is often the faster route to net zero for property portfolios. This is particularly true for buildings constructed between the 1960s and 2000s, which typically have solid structures but inefficient systems. Upgrading those systems can bring performance close to new-build standards without the carbon penalty of demolition.

Cooling systems offer major efficiency gains through controls and data

Cooling energy represents a substantial portion of building operational emissions. In commercial buildings, air conditioning and ventilation systems often run longer than necessary or at higher capacities than required. This is especially common in buildings where controls have not been updated since installation.

Natural Resources Canada recommends several measures to reduce cooling energy use. Optimising chilled water temperatures is one key step. Variable speed equipment allows systems to ramp down during periods of lower demand. Economiser modes use outside air for cooling when external temperatures permit, reducing the need for mechanical refrigeration.

Data-driven building management systems enable more sophisticated control strategies. These systems monitor occupancy, internal temperatures and external conditions in real time. They adjust HVAC operation dynamically rather than following fixed schedules. As a result, buildings avoid overcooling empty spaces or running systems during hours when passive ventilation would suffice.

Smart thermostats and zoning further improve efficiency. Different areas of a building often have different cooling needs depending on orientation, occupancy and internal heat sources. Zoning allows each area to be managed independently, reducing wasted energy in spaces that do not require full conditioning.

Maintenance also plays a critical role. Dirty filters, leaking ducts and poorly calibrated sensors all reduce system efficiency. Regular maintenance combined with continuous monitoring helps identify issues before they significantly increase energy consumption. Therefore, many retrofit projects focus on improving both controls and maintenance regimes alongside any equipment upgrades.

Eight key facts about building retrofit and carbon reduction

• Retrofitting existing buildings can avoid 50% to 75% of embodied carbon emissions compared with demolition and new construction, according to research from the American Institute of Architects and RMI.
• Deep retrofits typically deliver 30% to 50% or greater reductions in energy use and greenhouse gas emissions, as reported by the World Economic Forum.
• Historic England case studies show operational emissions cuts of over 60% in many retrofitted buildings, with some residential projects achieving reductions up to 84%.
• Embodied carbon in an existing building represents sunk emissions from materials, manufacturing, transport and construction that are lost if the building is demolished.
• Optimising chilled water temperatures, using variable speed equipment and applying economiser modes are proven methods for reducing cooling energy demand in existing buildings.
• Data-driven building management systems allow HVAC equipment to respond to real-time conditions rather than fixed schedules, cutting energy waste in unoccupied or lightly used spaces.
• Buildings constructed between the 1960s and 2000s often have structurally sound frames but inefficient mechanical systems, making them strong candidates for performance upgrades.
• Pairing energy efficiency retrofits with renewable electricity supply and electrification of heating systems can deliver further emissions reductions beyond operational efficiency alone.

What UK businesses should consider for existing property

Most UK commercial property predates modern building regulations on energy performance. These buildings were designed when energy was cheap and carbon was not priced. Consequently, they often have oversized or inefficient systems, poor controls and limited insulation.

Regulatory pressure is increasing. Minimum Energy Efficiency Standards already require commercial properties to meet EPC band E. The government has consulted on raising that threshold to band B by 2030. Meanwhile, procurement rules such as PPN 06/21 require suppliers bidding for central government contracts above £5 million per year to publish carbon reduction plans and demonstrate progress toward net zero.

Tenants are also driving change. Larger occupiers increasingly include energy performance criteria in their property searches. Some refuse to lease buildings below a certain EPC rating. Additionally, investors are applying environmental, social and governance criteria that favour low-carbon assets. Properties with poor energy performance face higher vacancy risk and lower capital values.

Retrofit offers a practical response. A phased approach allows building owners to spread costs and prioritise measures with the shortest payback periods. Typical first steps include upgrading building management systems, improving controls and addressing maintenance backlogs. These measures often deliver quick wins in energy reduction without major capital expenditure.

More comprehensive retrofits might include fabric improvements such as better insulation, window upgrades or air tightness measures. Replacing end-of-life plant with high-efficiency equipment is another common step. However, fabric and equipment upgrades are usually more cost effective when planned alongside major refurbishment or change-of-use projects rather than as standalone works.

Renewable energy can complement efficiency measures. Rooftop solar panels, for example, reduce reliance on grid electricity and provide a visible sustainability credential. Nevertheless, efficiency should come first. Reducing demand lowers the size and cost of any renewable installation required to meet remaining energy needs. Our net-zero program for carbon reporting compliance helps businesses identify priority measures and sequence them effectively.

Funding and incentives vary. Some retrofit measures qualify for enhanced capital allowances or other tax reliefs. Local authorities occasionally offer grants for specific building types or technologies. However, the business case for many efficiency upgrades now stands on its own, driven by energy cost savings, regulatory requirements and asset value protection.

Documentation is important. Building owners should maintain records of baseline energy consumption, measures implemented and verified savings. This data supports EPC assessments, carbon reporting and tender submissions. It also provides evidence of due diligence for ESG disclosures and investor reporting. Our compliance services support businesses in managing these reporting requirements.

Where to find authoritative guidance on building retrofit

The UK government provides detailed guidance on improving energy performance in existing buildings. The Department for Energy Security and Net Zero publishes policy documents and technical standards related to building efficiency and net zero targets. Their guidance is available at gov.uk.

Historic England offers specific advice on retrofitting traditional and historic buildings. Their research includes case studies showing how different building types respond to various retrofit measures. This guidance helps property owners balance energy performance with conservation requirements. It can be accessed through the Historic England website.

The Institution of Engineering and Technology has published standards and guidance on building services and energy management systems. These documents cover design, installation and commissioning of HVAC controls and building management systems. Professional engineers and facilities managers often use these standards when specifying retrofit projects.

For businesses managing carbon reporting and reduction planning, SBS Academy training covers practical approaches to building energy assessment and retrofit prioritisation. This training is designed for SMEs navigating compliance requirements and preparing carbon reduction plans for procurement purposes.