Multi-level properties—whether they are townhouses, duplexes, or large detached homes—pose unique challenges when it comes to Energy Performance Certificate (EPC) assessments. When these properties rely on split HVAC systems (different heating and cooling units for different floors or zones), the complexity increases, often leading to rating variations and unexpected recommendations.
In this article, we’ll explore how split HVAC systems affect EPC scores, the common issues assessors face, and what property owners can do to optimise their results.
1. Understanding Split HVAC Systems in Multi-Level Properties
Split HVAC systems divide the heating and cooling load between different units, often based on zones or floors.
For example:
Ground floor: Gas boiler with radiators
Upper floor: Electric heat pump system
Loft space: Portable air conditioning unit or fan-assisted heating
While this zoning improves comfort and control, it can complicate EPC evaluations because different systems have different efficiency ratings.
2. Why Split HVAC Systems Create EPC Assessment Challenges
From an EPC perspective, the challenges include:
a) Mixed Energy Sources
Gas, electricity, and renewables may all be in use—making it harder to calculate a standardised efficiency score.
b) Inefficiency in Partial Loads
If one system is less efficient than the other, it can drag down the overall rating, even if the rest of the property is well-optimised.
c) Distribution Losses
Some split systems require long duct runs or pipework between floors, which can result in heat loss or gain that affects EPC performance calculations.
d) Incomplete Control Integration
Without a unified smart control system, split HVAC setups often operate independently, wasting energy when zones are heated or cooled unnecessarily.
3. How EPC Assessors Approach Split HVAC Properties
An EPC assessor will evaluate each heating and cooling source separately, assigning efficiency values based on its technology, installation quality, and control system.
This often includes:
Measuring insulation levels in walls, floors, and ceilings between zones
Checking if thermostatic radiator valves (TRVs) or smart thermostats are in place
Considering the age and SEER/COP ratings of heat pumps or air conditioning units
Assessing ventilation and airflow between levels
4. Improving EPC Scores in Multi-Level Properties
To prevent split HVAC setups from lowering your EPC rating, property owners can take these steps:
Upgrade older units to modern, high-efficiency models
Install a central smart control system to manage all zones more efficiently
Improve insulation between floors to reduce heat transfer
Seal ducts and pipework to minimise energy loss
Use renewable integration like solar PV to offset electrical heating loads
5. Why It Matters for Property Value
With UK property buyers increasingly aware of EPC scores—and landlords facing stricter Minimum Energy Efficiency Standards (MEES)—improving your EPC rating can directly affect saleability and rental income.
If you have a complex, multi-level property and need a quick assessment, Urgent EPC’s same-day EPC service ensures you get fast, accurate results and expert advice for improvements.
Get an EPC for Your Multi-Level Property Today
Whether your building has split HVAC systems, unusual layouts, or mixed heating sources, our team can help you secure an accurate rating and suggest targeted upgrades.
📞 Contact us or view our pricing plans to book your EPC inspection now.
