Easy as EPC?

Let’s get this out of the way first; EPC’s or Energy Performance Certificates are pretty dull - but they just became a pretty hot topic in the commercial office world. This month every building owner with a poor EPC will get an innocuous looking letter from their Council which will be advising that legislation agreed in 2018 to set Minimum Energy Efficiency Standards [MEES] will come into effect in April 2023.  This legislation means that it is illegal to sell or let commercial space with an EPC rating below E, which affects 18% of current commercial office stock in the UK.

If you don’t know what an EPC is; it’s a bit of paper which tells you how energy efficient your building is. It’s backed up by scientifically measured data based on a detailed survey of the property, its fabric and the equipment used to heat, cool and light it. Simple.

Written by Alex Davis

So what’s the issue?

For years landlords have had to have their properties assessed and certified in order to sell or let them - just like in the residential market - but without any specific target or worry. You can achieve a rating of A to G, and tenants would either ignore it or just accept that their bills might be slightly higher. 

But now the landscape has changed dramatically, not only are we in the midst of a world energy crisis - meaning electricity and gas prices have doubled* in the last six months but the bottom has also fallen out of the commercial office market.

Post Covid, many workers and employers prefer a hybrid model of work from home and not to come back into the office full time [or at all] meaning that may companies are trying to downsize their offices or find better quality premises that entice people back to work. The other less quantifiable issue is image. ESG ‘Sustainablity Credentials’ and ‘Environmental Integrity’ are phrases that carry huge weight in marketing; affecting everything from pensions and investment portfolios to chocolate bars. 

I’m sure we have all noticed a more ‘green’ bias in advertising. That’s because more and more customers are voting with their feet to put their money behind more ethical corporations, meaning that accreditation schemes for company sustainability such as B-Corp are gaining more traction. Not only does sustainability affect the marketability of the individual company, but also their ability to do business - because B-Corps audit their subcontractors. 

As an example; I recently heard a story of a London based advertising agency losing out on a job because they couldn’t prove their sustainability credentials to the new Client - because they were in an F rated office space!

No matter what your buildings current EPC rating is, improving it is pretty much a no-brainer, as the market is much more competitive than it used to be and and the trifecta of issues above mean that tenants are really paying attention.

So back to EPC’s!

‘How can we improve our ratings?’ I hear you ask - well it’s surprisingly simple. 

First, if your existing EPC was issued over 5 years ago, it’s probably time to get a draft assessment done again - as a new one will highlight the areas you can improve your score, but following the simple principles below will dramatically improve the buildings performance.

Reduce Energy usage [Easy wins]

  • Switch to LED lighting to reduce energy consumption

  • Add zoned Heating controls with programmable thermostats

  • Replace existing plant with more efficient Heating Ventilation and Air Conditioning equipment [HVAC]

Reduce Energy Loss [As part of a longer strategy]

  • Improve the fabric of the building by replacing windows or adding insulation to walls or roofs.

  • Get an air tightness test done and act on the results - as this affects the score significantly.

Generate Energy on site 

  • Install a solar PV array on the roof to generate energy and store in batteries - for which there are incentives available.


Whether on new build or refurbishment projects, we follow the same principles in the studio to ensure our buildings perform to the highest standards. 

At The Gramophone Works, the lighting to the large open plan floors was designed as a zoned LED system on PIR’s to automate the switch off when an zone was inactive. The BMS was a monitored smart system, allowing for life cycle optimisation, and the roof has over 250m2 of PV panels.

At The Bottle Factory, a listed warehouse building, we were unable to modify the exterior of the building, and the interior was to shell and core spec, so we improved the roof insulation and air tightness. 

At Roots in the Sky, we combined significant fabric improvements with openable windows and air source heat pumps. The central atrium improves access to natural daylight and reduces demand on electrical lighting.


Improving your buildings energy performance is not only a statutory requirement, but it will also give you a more lettable asset both now and in the future - and no matter what type of building you have, there are many ways to improve its energy performance.

The other important takeaway from this however is that standards will continue to be raised - and by 2030, properties will need to achieve a B rating as a minimum - so as an industry and individually, we need to make a plan for the coming years.