For owners and landlords of industrial property, the Energy Performance Certificate has gone from a box-ticking formality to a genuine commercial concern. A poor EPC rating can prevent you from letting a unit, reduce its market value and signal high running costs to prospective tenants. With Minimum Energy Efficiency Standards tightening, understanding how to improve a warehouse EPC rating has become essential knowledge for anyone who owns or manages industrial buildings.

This guide is not legal advice. It is a practical explanation of what affects an industrial EPC rating and what you can realistically do to improve it, ranked by cost and disruption.

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What an EPC Rating Actually Measures

 

An Energy Performance Certificate rates a building's energy efficiency on a scale from A (most efficient) to G (least efficient). The certificate is produced by an accredited assessor and is valid for ten years. For commercial and industrial buildings, the assessment is based on the building's design, construction and fixed services rather than on the actual energy bills, which means the rating reflects the building itself rather than how the current occupier uses it.

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The EPC assessment for an industrial building considers several factors:

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• The building fabric: Insulation levels in the walls, roof and floor, and the air tightness of the structure

• The heating system: The type, age and efficiency of the fixed heating equipment

• Heating controls: How well the heating can be controlled by time and temperature, and whether zoning is possible

• Lighting: The efficiency of the fixed lighting installation

• Hot water and ventilation: Where these fixed services are present

• Any renewable technologies: Solar panels or other on-site generation

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It is worth understanding that the rating is a calculated figure, not a measurement. The assessor inputs the characteristics of the building into approved software and the software produces the rating. This matters because it means improving the rating is about changing the inputs the software uses, and some changes move the rating more than others.

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Why Your EPC Rating Matters

 

There are three reasons an industrial EPC rating matters commercially.

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The first is legality. Under the Minimum Energy Efficiency Standards (MEES), since April 2023 it has been unlawful for a landlord to continue letting a commercial property with an EPC rating below E. This applies to existing leases, not just new ones. The government has previously consulted on raising the minimum threshold for commercial property, with a B rating by 2030 having been proposed, though the timetable has been subject to revision. The direction of travel is clear: the minimum standard is tightening.

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The second is value. An industrial unit with a poor EPC rating is worth less than an equivalent unit with a good rating. Buyers and their lenders increasingly factor energy performance into valuations and lending decisions. A poor rating can reduce the price or make a property harder to sell.

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The third is lettability. Prospective tenants read the EPC rating as a proxy for running costs. A unit rated F or G signals high heating bills, and tenants will either negotiate the rent down or look elsewhere. A good rating is a selling point that helps a unit let faster and at a better rent.

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Building Fabric: High Impact, High Cost

 

The fabric of the building, meaning the insulation and air tightness of the walls, roof and floor, has a significant effect on the EPC rating. A poorly insulated warehouse with a single-skin metal roof and uninsulated walls will struggle to achieve a good rating regardless of what else is done.

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Improving the fabric is the highest-impact change available, but it is also the most expensive and disruptive. Options include:

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• Roof insulation: Adding insulation to the roof, or overcladding an existing roof, significantly reduces heat loss. This is a major project but it has the largest single effect on the rating for most warehouses

• Wall insulation: Insulating or overcladding external walls reduces heat loss through the building envelope

• Improving air tightness: Sealing gaps, improving door seals and addressing draughts reduces uncontrolled heat loss

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Fabric improvements are worth considering when a building is undergoing major refurbishment anyway, or when the rating is so poor that nothing else will lift it far enough. For many buildings, however, the cost and disruption of major fabric work is hard to justify on EPC grounds alone. This is why the heating system is often the more practical place to focus.

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The Heating System: The Practical Place to Focus

 

For most existing warehouses and industrial units, upgrading the heating system is the most practical and cost-effective way to improve the EPC rating. The heating system is a major input into the EPC calculation, and unlike the building fabric, it can usually be upgraded without major structural work or extended disruption to the occupier.

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An old, inefficient heating system drags the rating down. Many industrial buildings are still heated by gas-fired warm air heaters that are 15, 20 or more years old, with seasonal efficiencies of 70% to 80%. Replacing these with modern high-efficiency equipment improves the rating directly because the assessment software recognises the better efficiency figure.

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Upgrade to High-Efficiency Heaters

 

Modern condensing warm air heaters achieve dramatically better seasonal efficiency than the older units they replace. The Apen LKN is a condensing gas-fired unit heater achieving up to 109% seasonal efficiency. Replacing older non-condensing heaters with condensing units improves both the EPC rating and the actual running cost of the building.

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For buildings where the existing heater sits in a purpose-built enclosure and a standard replacement will not fit, the Hadar Replicant can be built to the same dimensions as the obsolete unit with modern high-efficiency components inside, avoiding the cost of rebuilding enclosures and ductwork. For a broader upgrade, the Hadar Vortex combines heating, ventilation and cooling in a single high-efficiency unit.

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Consider Low-Carbon Heating

 

The EPC calculation considers the carbon intensity of the fuel as well as the efficiency of the equipment. Heating systems that use lower-carbon energy sources score better. An LPHW system driven by an air-source heat pump uses electricity rather than burning gas on site, and as the electricity grid continues to decarbonise, the carbon intensity of electric heating continues to fall. For buildings where a heating system is being replaced anyway, considering a heat pump driven LPHW system can deliver a meaningful improvement in the EPC rating.

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Improve the Heating Controls

 

The EPC assessment gives credit for good heating controls. Time control, temperature control, zoning and optimum start controls all improve the rating. Upgrading the controls on an existing system is relatively inexpensive and can deliver a worthwhile improvement. This is one of the lowest-cost changes available.

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Add Destratification Fans

 

Destratification fans improve the efficiency of a warm air heating system by recovering warm air from ceiling level and returning it to the occupied zone. The Hadar DSF reduces the energy a warm air system needs to maintain comfort, and a more efficient heating system contributes to a better EPC rating. Destrat fans are a low-cost addition relative to the saving they deliver.

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Lighting: A Quick Win

 

Lighting is one of the easiest and most cost-effective EPC improvements available. If a warehouse still uses older fluorescent or metal halide lighting, replacing it with modern LED lighting improves the EPC rating and reduces electricity consumption. LED lighting upgrades are relatively inexpensive, quick to install and disruptive only for a short period. Adding lighting controls such as occupancy sensors and daylight dimming improves the rating further.

For many industrial buildings, an LED lighting upgrade combined with a heating system improvement is enough to lift the rating by one or more bands without touching the building fabric at all.

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Renewable Technologies

 

On-site renewable generation, most commonly rooftop solar panels, improves the EPC rating because it offsets some of the building's energy demand with low-carbon generation. A large warehouse roof is well suited to solar panels and the rating benefit can be significant. The capital cost is higher than lighting or controls but lower than major fabric work, and there is the additional benefit of reduced electricity bills for the occupier.

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A Practical Approach to Improving Your Rating

 

If you need to improve the EPC rating of a warehouse or industrial unit, the sensible approach is to start with the most cost-effective changes and work upward only as far as you need to:

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• Start with lighting: An LED upgrade with controls is low cost, quick and reliably improves the rating

• Address the heating system: Replace old inefficient heaters with high-efficiency condensing units, improve the controls and add destratification fans. This is usually the highest-value change after lighting

• Consider renewables: If the rating still needs to improve, rooftop solar offsets energy demand and improves the rating

• Major fabric work last: Roof and wall insulation has the biggest single effect but the highest cost and disruption. Consider it when the building is being refurbished anyway or when nothing else will lift the rating far enough

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One important point: get a qualified EPC assessor involved early. Because the rating is a calculated figure, an assessor can model the effect of different improvements before you spend any money, telling you which combination of changes will lift the rating to the band you need. Spending money on improvements without modelling them first risks missing the target band or overspending.

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How Hadar Industries Can Help

 

Hadar Industries supplies and specifies high-efficiency industrial heating systems that contribute directly to a better EPC rating. We can assess your existing heating system, recommend the right high-efficiency replacement and advise on controls and destratification to get the most from the system.

If you are working to improve the EPC rating of a warehouse or industrial unit, contact Hadar Industries today for a free site survey. We will assess your heating system and recommend the upgrades that will deliver the best improvement for your building.