I was recently given the task of assessing some derelict mill buildings that hadn’t been used for the last 15 years. They were originally built to mill corn in 1767 and more recently hosted a foundry and workshops.

While they are wonderful, Grade II listed buildings – still with water wheel intact – there’s no heating or lighting and they’re resident to several families of pigeons. The buyer wanted to rescue them (the buildings, not the pigeons), retrofit, then rent the buildings out as a social enterprise for creatives – he even had 12 tenants lined up, ready to move into craft workshops. Aware that he had to pacify a range of stakeholders, he’d already met with English Heritage, structural engineers and the fire officer – but the purchaser’s solicitor had requested an EPC.

It was 50:50 whether the buildings were covered by the Energy Performance of Building (EPB) Regulations. And even if an EPC was registered, it would likely be a poor rating (an F or G) which would mean the buyer wouldn’t be able to rent out the units without first carrying out energy efficiency improvement works at great expense or apply for a five-year exemption under the Minimum EPC Standards. In a case like this, it’s frustrating for a buyer for whom a building’s energy credentials aren’t relevant, and who doesn’t plan to introduce heating to the new workshops. If he’s forced to follow the letter of the law, it could result in him backing out of the sale, and those buildings would be left to further decay, while the vendor – who wants to dispose of the asset – may no longer have the energy or motivation for redevelopment.

You don’t see a mill for ages and then two come along at once. I’ve had an inquiry about another old mill that’s only been partly occupied for many years. The imposing Imperial Mill in Blackburn dates back to the early 1900s and housed 90,000 ring spindles at the height of its powers. Now Blackburn with Darwen Council hopes to buy and transform it into one of four proposed cultural hubs on the Leeds-Liverpool Canal. I’ve already raised the point that an EPC is not the purchaser’s responsibility, but the vendor’s. A listed building is not automatically exempt from the EPB Regulations; if it can be demonstrated that the energy efficiency improvement measures recommended by the EPC assessment would not be permitted due to the listed status, then the EPC does not need to be registered.

Sometimes this pragmatic approach is the most appropriate and I’m happy to advise clients on the correct legal position. So, if the EPC is not required by law, then we would highlight this. If the client still wants to proceed, then we will of course oblige – many don’t. In the case of the mill at Alston, the purchaser’s solicitor accepted our reasoning for an EPC not being required for the sale. Of course, there are Energy Assessors happy to produce commercial EPCs on any existing building, but Murton & Co cover the broad range of energy assessments on both existing buildings and new builds so we can consider each project from a holistic perspective. This is particularly useful in cases like these or when someone wants to develop a site as part housing, part workshops.

Obviously, it’s great when developers can return these old buildings to use. After all, they’re often centrally located with small rooms that are more suited to the needs of today’s workers – think yoga workshops, craftspeople and small artisan companies. This also has an environmental benefit given that the CO2 emissions that were emitted during their original construction are not compounded by demolition and re-build.

The 152-year-old Grade II listed India Mill in Darwen, with its iconic 303ft chimney – now home to TV Licensing’s call centre – is a particularly good example of a successful refurbishment in the Northwest, while there are plenty of other good examples around the UK. We can accompany clients on their journey to restore an historical building to its original character while improving its energy credentials – something that could well become more prevalent in light of the proposed Part Z of the Building Regulations. These would introduce an embodied carbon assessment into construction projects and EPCs, ensuring that embodied carbon is assessed as part of a comprehensive whole life carbon assessment. It would also ensure that embodied carbon emissions are capped on all major construction projects. Existing buildings would then certainly be viewed as preferable to new builds as the carbon emissions have already been spent. An EPC for an existing building that’s been enhanced would win hands down.

Once you’ve decided to go ahead with making energy improvements to an historic or listed building, it always helps to get around the table with all parties involved to understand their needs, what they can offer you and to fill them in on any energy calculations. You’ll probably soon discover that the standard retrofit solutions don’t always apply. A case in point was the rush to fit cavity wall insulation a few years back which is now being extracted from many older buildings – and more modern dwellings – because it should never have been used. Historic buildings were constructed with breathable materials to allow moisture vapour to pass through the fabric, which means you can’t apply the sort of insulation you would use on a non-breathable new build; simply putting petrochemicals on external walls creates an unnecessary barrier. The ‘fabric first’ strapline (seemingly side-lined of late) is relevant here and perhaps should be re-worded to a ‘risk-based approach’. It’s important to look at your options before embarking on any works, and the Sustainable Traditional Buildings Alliance has a useful tool, the Responsible Retrofit Guidance Wheel, which nicely illustrates the complexities of tackling these buildings (and to be fair all buildings) depicting more than 50 measures and highlighting advantages, concerns about their performance and possible interactions between them.

Bringing old buildings back to life sympathetically benefits local people who often have an emotional attachment to these landmarks, while updating and turning them into service hubs based around a community’s needs has got to be a good thing. Working on these projects is always interesting and grist to the mill!