The Minimum Energy Efficiency Standards now make better EPCs and decarbonisation for commercial property owners mandatory.

If you are a commercial property owner in the UK, then every building you lease needs to have an EPC rating of E or higher. Any landlord with an insufficient rating can no longer legally rent their property and could face fines of up to £150,000 from Trading Standards. This applies to all commercial property, including listed buildings, and there are very few exceptions to the rules.

This is just the beginning: further updates to the standards are planned out for 2030, with a minimum EPC rating of C expected to be enforced by 2027. 

The good news is that there are two clear stages and six steps that you can take to improve the energy efficiency of your property. Following this advice is designed to be cost-neutral within a few years, based on the money you will save from reducing your energy bills, so there are no real downsides to taking action now.

What are MEES and EPCs anyway?

MEES stands for Minimum Energy Efficiency Standards, a government scheme set up in 2015 to help decarbonise non-domestic properties across the UK. MEES covers all existing buildings (whereas Building Regulations focus on new buildings). Compliance with MEES involves taking steps to improve your EPC rating.

Energy Performance Certificates, or EPCs, predict how much energy a property uses per square meter and are rated from A to G – from very energy-efficient buildings with low running costs to very energy-inefficient buildings with high running costs.

Commercial EPCs are calculated using data collected by an energy assessor during an onsite inspection and produced using a Simplified Building Energy Model (or SBEM for short). 

Where data sources are missing (such as energy bills), or readings can’t be taken (inaccessible spaces or loft hatches hiding boilers, insulation, etc) the assessor has no option but to include assumed default data in order to complete the calculation. These are essentially the worst-case scenario numbers that show what the lowest possible value would look like. While this provides useful macro-level data to inform national decarbonisation policy, it has led to some unnecessarily low EPC scores that individual property owners have to grapple with. 

How to comply with the Minimum Energy Efficiency Standards

There are two stages to solving this challenge. The first focuses on improving your energy rating by feeding more accurate data into your energy model. The second looks at identifying additional energy reduction measures. These will improve the thermal efficiency of your building while reducing your energy bills and carbon emissions.

Stage 1: Improve your existing energy rating by feeding better data into the energy model (SBEM)

This stage looks at how you can improve your EPC rating and potentially become compliant with MEES without taking any additional energy-efficient actions. It works on the premise that if you put junk in, you get junk out… or more to the point, if you add worst-case scenarios into your energy model, it’s going to give you the worst-case EPC rating. That’s the assumed default data we mentioned earlier.

Tip 1: Commission an air tightness test

A common example of assumed default data is a property’s air tightness score. Buildings constructed before 1999 were not required to have an air tightness test. This meant that a default score of 25 m3/(h.m2)@50Pa was most often entered into the energy model. Most properties, however, have an air tightness score between 5 – 10 m3/(h.m2)@50Pa. The difference between these two values is significant! It could make the difference between an EPC rating of F or E: a pass or a fail. 

So if your property is over 20 years old, you should get an air tightness test. All things considered, this should be your first action in tackling a low EPC rating.

Tip 2: Consult with a Commercial Energy Assessor 

If you think your EPC may have been produced using lots of assumed default data, seek advice. Contact a competent commercial energy assessor and outline the steps you have already undertaken. Find out how much they think an air tightness test score of between 5 – 10 would improve the SBEM score and, ultimately, the EPC rating.

Additionally, if you have made any significant upgrades to the building fabric since your last EPC was produced, your rating could be significantly improved by adding this new data into the SBEM calculation.

Tip 3: Produce a new EPC certificate

Once all new data has been added to the SBEM, your EPC score can be recalculated. The new certificate will be valid for ten years, which will give you time to look at additional enhancements to the thermal performance of the building. 

Low-energy lights are one of the first measures to take in any decarbonisation project.

Stage 2: Identify new energy efficiency gains 

If your energy assessor is sure that the numbers are accurate and no significant default data has been used in the model, you will need to make additional changes to your property to improve your EPC score. 

Tip 4: Research available funding options

You have a lot of options available to you. Firstly, start with the easy and cheap options like upgrading your lighting system to LEDS. You can then progress through to harder and more expensive options. These include replacing your gas heating system with a renewable system, and other significant investments. 

There is a lot of government funding available to help cover the cost of these changes, in addition to low-cost business loans.

Tip 5: Identify areas for improvement with a thermographic survey

Funding upgrades to your property is one thing… but how do you know which option to choose overall?

We recommend that you start by looking at making changes to the building fabric itself. Ensuring that the property is airtight, well-insulated, and properly ventilated should always be done before new heating systems are considered. This is specifically called a Fabric First approach.

Understanding where to start with these improvements can be done very effectively with a thermographic survey. This will give you a practical, real-world view of cold spots, thermal bridges, and air leaks.  

Thermographic images can highlight where cavity wall insulation is missing, for example, or show where air is escaping from around windows, and whether roof hatches are moving heat into empty loft spaces.

Tip 6: Eradicate assumed default data with a borescope inspection 

An additional tool in this type of investigation is a borescope. These handy hand-held devices enable an energy assessor to access areas of a building otherwise hidden from them. Wall cavities, crawl spaces, ceiling hatches, and other tight spaces are all now accessible. This means that assumed default data can effectively be eradicated by using this tool.

What next?

If you are worried about a poor EPC score, we can help. Our team of sustainability consultants, testing engineers, and energy assessors can provide:

We are working with an increasing number of companies on commercial decarbonisation projects. We help them to identify significant cost savings from their energy bills. So if this sounds like you, then get in touch.

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