It’s not uncommon for clients to feel a little overwhelmed when they first see the cost of a Level 5 EPC, especially when comparing it to a Level 3 or Level 4 assessment. However, that initial sticker shock often fades once they understand the deeper benefits that come with it.
Certain complex buildings—such as those with atria, automatic blind control and advanced ventilation systems that thermally couple to the structure—do require a Level 5 assessment. Yet we’re seeing more clients opt for Level 5 EPCs proactively because they recognise the exceptional value in the detailed insights provided.
The distinction between Level 3, Level 4 and Level 5 commercial Energy Performance Certificates (EPCs) is driven by both building complexity and the software required to model it accurately. Level 3 and Level 4 assessments use simplified or standardised calculation tools suited to conventional building forms. In contrast, Level 5 EPCs are reserved for buildings with complex features or systems, where Dynamic Simulation Modelling (DSM) is essential to capture real‑time interactions between the building fabric, systems and environmental conditions.
At CCA Environmental, we use IES‑VE software—and have done so for over 17 years—to deliver these advanced assessments. IES‑VE is a powerful, industry‑leading simulation platform that provides highly detailed insights into a building’s energy efficiency and environmental performance, ensuring exceptional accuracy in EPC production.
Unlocking the Full Value of a Level 5 EPC Assessor
When it comes to maximising the benefits of a Level 5 EPC assessor, preparation is a crucial first step. Before the assessor even visits your site, providing detailed floor plans—ideally in CAD format—is essential. These plans help import the building layout directly into the software, forming the foundation for creating an accurate and reliable 3D model.
But the groundwork doesn’t stop there. A significant part of achieving a superior asset rating lies in the on‑site assessment. This is where the diligence and expertise of your energy assessor truly shine. They’ll spend time with the facilities manager or engineers on site, delving into the operation and maintenance (O&M) manuals. These manuals are like gold dust—they hold vital details about the building’s systems and equipment, and incorporating this information ensures that the model is as thorough and accurate as possible.
Why does this matter? Because the more complete and precise the input data, the more accurate the final asset rating will be. A less diligent assessor might produce a less favourable asset rating simply because they haven’t gathered all the relevant input information.
Once the initial model is established, it becomes a dynamic digital twin that you and your team can use to explore different recommendations and scenarios before committing to any major decisions. You can choose to finalise and lodge the EPC, or you can simulate proposed changes, test energy‑saving measures and understand their impact long before investing in real‑world modifications.
Because of the nuances in how EPCs are assessed, it isn’t always obvious from a mechanical and electrical perspective which interventions will genuinely improve the asset rating. Having a digital twin within IES‑VE allows you to implement ideas quickly, test them with precision and immediately see whether your proposals deliver meaningful benefits to the EPC outcome.
In the end, that extra effort—working with a diligent, proactive assessor—pays off. You’ll have a well‑informed, accurate model that supports better energy performance and more confident decision‑making in the future.
This article was written by Neil Bajaj at CCA Environmental Limited. If you need any assistance with Level 5 EPCs or dynamic modelling work, feel free to get in touch with us via LinkedIn. We’d be happy to help you navigate your energy performance needs!