In January this year, the government confirmed a new minimum energy efficiency standard (MEES) for England’s social rented homes.
For housing associations, the biggest implication is that this is no longer about improving EPCs where possible. It is now a compliance requirement that needs to shape retrofit planning, procurement and investment decisions across the portfolio.
The old approach was about getting homes closer to EPC C. The new approach needs social landlords to plan for EPC C or equivalent under the reformed framework, with compliance achieved through new ‘phased’ metrics rather than just one.
The three metrics are fabric performance, heating system and smart readiness.
For the social rented sector, the confirmed route is to meet EPC C or equivalent on one reformed EPC metric by 1 April 2030, and then meet a second metric by 1 April 2039.
There is also a £10,000 spend exemption, and homes that already reach current Energy Efficiency Rating (EER) C before 2030 can continue to count as compliant until that certificate expires. And while that gives some transition time, it does not remove the need to rework retrofit programmes now.
The government has also framed the new Decent Homes Standard as a way to give registered social landlords (RSLs) , the certainty they need to finalise business plans for improving existing homes and building new ones. That matters because MEES planning is not happening on its own – it sits inside wider decisions on investment.
Why MEES matters more than the previous EPC metrics
This matters because the technologies and upgrade pathways that worked under the old EPC system and logic are not always the ones that best support the new route.
Under the new framework, it’s not just about social housing landlords to move their stock to EPC C, but to have a more holistic view of transitioning, and understand which metric can get their stock to compliance most effectively.
That is where many retrofit programmes will need to be reassessed. Some homes will still need a strongly fabric-led route, while others may get there more practically through the heating system metric first. And once you start following a heating system route, one challenge that comes into focus quickly is hot water.
Why hot water now needs more attention
As social housing moves away from older gas boilers and inefficient direct electric heating or electric storage heaters, domestic hot water becomes a bigger part of the challenge. Space heating can be improved through fabric-first and low-carbon heating changes. But moving away from existing combi boilers in social homes means hot water storage becomes a challenge in space-constrained flats & homes. This is why the heating system metric shifts attention towards the whole in-home system. In practice, that means landlords need to think about how hot water is produced, the space it takes, heat losses, maintenance requirement and reliability of the system for tenants.
For housing associations, this affects resident experience, usable storage space & floor space, retrofit disruption and long term running costs.
Why this matters in social housing more than in many other sectors
In private homes, people may accept bigger storage units, more disruption or awkward cupboard space, especially if they choose it themselves. In social housing though, landlords are making practical decisions across many homes at once. So they’re working with diverse housing stock , homes where cupboard space matters more, residents who need simple, reliable systems that require little mantenance, and implementation programmes where disruption has to be kept low. Thus, hot water choice becomes a crucial lever in retrofit programmes.
What the new Decent Homes Standard adds
The government has also made clear that this is not just an energy discussion; the updated Decent Homes Standard now brings together hazards, repair, thermal comfort, core facilities, and damp and mould. That matters because poor hot water and poor ventilation can quickly become wider housing quality problems, not just energy problems.
The new standard is built around five criteria i.e. hazards, repair, core facilities and services, thermal comfort, damp and mould.
That is relevant because once landlords upgrade fabrics and change heating systems, they also need to avoid creating new moisture and ventilation problems. In the policy statement, the government has also made clear that mechanical ventilation is part of the repair picture, and that a home can be non-decent if damp and mould have not been remedied.
Why the March 2026 Future Homes and Buildings Standards update is relevant
A second policy update followed in March 2026. On 24 March, the government published its Future Homes and Buildings Standards circular, along with updated Approved Document L and Approved Document F for dwellings. While this doesn’t alter the January 2026 social housing MEES decision, it is useful because it gives more context on where housing standards are moving next.
For housing associations, the main point of this March update is that all new homes will need heat pumps and most will require onsite renewable energy generation such as solar PV. Requirement L3 now requires on-site renewable electricity generation for new dwellings, and the government’s own dwelling specification uses solar PV equivalent to 40% of ground floor area as its benchmark.
That makes another point more relevant for hot water. As new homes move towards PV plus electric heating, hot water storage needs to be specified early on into the project plans as part of the wider system rather than treating it as an afterthought. If a home is generating electricity on site and using electric heating, then how and when hot water is heated becomes more important. A high-performance hot water system can help a home make better use of its own generation and reduce waste. A low-loss hot water system can help the home use electricity more effectively, especially where hot water heating is timed to match on-site generation or lower-cost tariff periods. While that isn’t a direct requirement of the standard, it is a practical implication of the way these homes are now being designed.
The strongest takeaway for social landlords is in Approved Document F. It says energy efficiency works in existing homes can reduce infiltration and leave homes under-ventilated. That is directly relevant to social housing retrofit, because many landlords are improving fabric and changing heating systems at the same time.
For housing associations, the point is that once homes become tighter with upgraded fabrics and heating systems change, domestic hot water cannot be looked at only as a cylinder choice; it becomes a question of whether the hot water storage choice can effectively, practically and at scale be a part of the wider retrofit or new build design.
How Sunamp’s compact hot water storage addresses the retrofit challenge for housing associations
Thermino can help with one of the most practical problems social landlords face under a heating system or electrified retrofit led route, ie. how to provide hot water in a small footprint without the constraints of a large traditional cylinder?
That matters in social housing because compact hot water storage can help address several real issues at once:
- preserving cupboard & usable floor space in smaller flats
- cutting the installation issue related to low-carbon hot water retrofit into flats
- lowering standing heat loss compared with larger ‘stored’ hot water systems
- supporting simpler, more practical in-home layouts for residents
If the heating system metric of the new MEES pushes landlords to rethink the low-carbon heating systems in their stock, then compact hot water storage becomes a critical part of that system thinking.
For Scotland and Northern Ireland
For housing associations working across the UK, it is worth noting that the policy route is not the same everywhere. In Scotland, social landlords are currently working under interim guidance while the Scottish Government reviews EESSH2 and develops a new Social Housing Net Zero Standard. In Northern Ireland, there is no direct equivalent yet to England’s new social housing MEES, but the direction is still towards whole-house decarbonisation. The Northern Ireland Housing Executive is already using a whole-house retrofit approach in its Low Carbon Programme, combining fabric upgrades, low-carbon heating and renewable technology to inform future planning and investment.
The January 2026 MEES decision is not just another EPC update. It changes the decision-making framework for social landlords. I. And once they do, domestic hot water becomes much more important than it first appears.
For many housing associations, the challenge will not simply be how to improve the fabric or change the heat source. It will be how to do that while still delivering practical, low-loss, space-efficient hot water in the homes they manage. That is where compact thermal storage, Thermino, plays a crucial role.
Sunamp has more than 35,000 Thermino heat batteries installed worldwide, including major UK social housing projects. In Thurrock, 273 flats across three tower blocks were retrofitted with ground source heat pumps and Thermino heat batteries, with estimated 67% lower energy bills and 70% lower carbon emissions for residents. In Sunderland’s Core 364 high-rise retrofit, the ground source heat pump paired with Thermino enabled gas to be removed from 364 homes, cutting carbon emissions by an about 420 tonnes/year (nearly 70%). In EastHeat in Scotland, more than 700 heat batteries were installed across 625 homes, including alongside solar PV and heat pumps, showing how compact hot water storage can also support wider renewable-led retrofit.
If you are reviewing how your homes will meet the new social housing MEES route, now is a good time to look beyond EPCs alone and consider what the new heating-system-led pathway means for hot water.
For social housing portfolios where space, disruption and long-term practicality matter, compact thermal storage Thermino is worth assessing early in their project stage.
FAQs
What is the main social housing MEES deadline?
Social landlords need to reach EPC C or equivalent on one reformed EPC metric by 1 April 2030, then a second metric by 1 April 2039.
Why does the heating system metric matter so much?
Because it shifts attention from general EPC uplift to the actual performance of the in-home system. That makes hot water, controls, layout and system practicality more important.
Why is hot water storage an issue in social housing while retrofitting?
Because many homes, especially flats, have limited space. A low-carbon heating route may be technically possible, but the hot water side still has to fit the home, work for tenants and avoid unnecessary loss and disruption.
Does the March 2026 FHS Building Regulations update change MEES?
No. It does not change the January MEES decision for social housing. But it does add useful context on where housing standards are moving, especially around on-site renewable electricity generation in new homes and the need to avoid under-ventilation after energy efficiency works.
What should housing associations review first?
Start with which metric route is most likely for each stock type. Then look at what that means for hot water, space, ventilation and resident practicality, not just the EPC outcome.
Related articles
Designing hot water systems that tackle fuel poverty: what ECO cuts and the Warm Homes Plan mean for housing associations
Britain’s hard-to-heat homes and aging housing stock: Designing retrofit-ready heating and hot water
