As we move into May 2026, many London landlords are breathing a sigh of relief. The government recently confirmed that the Home Energy Model (HEM) – the sophisticated new system for calculating energy ratings – has been delayed until late 2027.
While some are using this as an excuse to kick the can of energy efficiency further down the road, we believe this is actually a strategic emergency.
This two-year delay is a golden window. It is your chance to benchmark your portfolio and lock in your EPC ratings while the goalposts are still stationary. Here is why acting now – using the current system – is the smartest move you can make before the 2030 deadline.
Jargon Buster: Energy Terms Explained
Before we dive into the strategy, let’s clear up the alphabet soup of energy regulations:
- RdSAP (Reduced Data Standard Assessment Procedure): This is the old way of calculating Energy Performance Certificates (EPCs). It’s a simplified checklist where an assessor looks at your boiler, lightbulbs and insulation to give you a score.
- HEM (Home Energy Model): The new way, coming in 2027. Instead of a checklist, it’s a high-tech computer simulation that tracks how a home uses energy every 30 minutes. It is much harder to pass because it’s much more accurate.
- Fabric Performance: This is a fancy term for your building’s outer layer. It measures how well your walls, roof and windows actually hold in heat, regardless of what kind of fancy boiler you have.
The Sticking Point: Why the Change Matters
Under the current RdSAP system, you could often game the score. You might reach an EPC Band C by simply adding solar panels or a more efficient boiler, even if the walls are still thin and drafty.
However, the HEM system prioritizes Fabric Performance. In 2027, patching up a property with gadgets won’t be enough. The new model will look at how the building actually performs. If your walls aren’t properly insulated, the new software will be much less forgiving, potentially dropping a current Band C property back down to a Band D or E.
The 2-Year Strategic Window: Benchmarking While Stationary
By delaying HEM until 2027, the government has given you a period where the rules are fixed. Here is how to use this time to your advantage:
1. Lock in Your Band C Now
An EPC certificate is valid for 10 years. If you undertake improvements and get an EPC assessment under the current RdSAP rules in 2026, that Band C rating is locked in legally for a decade. This gives you a massive compliance cushion as we head toward the mandatory 2030 requirements.
2. Benchmarking the Skin of Your Building
Use our surveyor-led approach to perform a fabric audit now. Instead of just looking for the cheapest way to get a certificate, identify the structural weaknesses in your property’s thermal envelope (its skin). Improving insulation now is cheaper than doing it in 2029 when every landlord in London is chasing the same contractors.
3. Avoid the 2027 Cliff
When HEM launches in late 2027, we expect a massive bottleneck. Energy assessors will be retraining, the software will be new, and ratings will likely be more volatile. By acting in 2026, you avoid the chaos and the risk of a rating drop under the stricter new metrics.
Practical Advice for May 2026
- Don’t Wait: If your properties are currently at a Band D or E, start your retrofit plans this month.
- Focus on Fabric First: Even though the current rules allow you to cheat with tech, prioritize insulation and high-quality windows. This ensures that even when your 10-year certificate eventually expires, the building is already HEM-ready.
- Get a Professional Audit: A standard EPC is a tick-box exercise. A Homesearch Properties technical audit will look at your portfolio through a surveyor’s lens, identifying the structural changes that offer the best return on investment.
The Verdict
The HEM delay isn’t a day off, but a head start. By benchmarking your portfolio while the rules are predictable, you protect your asset value and ensure your properties remain bankable and let-able well into the 2030s.
Is your portfolio ready for the 2030 shift? Contact us today for a technical energy review.
