Frameworks such as the International Performance Measurement and Verification Protocol (IPMVP) exist to support the measurement and verification of efficiency investments to facilitate and scale-up global engagement in energy efficiency programmes. The IPMVP offers up four routes to determine savings across an entire facility, or for a portion of a facility, depending upon the characteristics of the energy efficiency measures (EEMs) implemented and the purpose of the reporting. The IPMVP is complementary to other industry guidelines, such as ASHRAE Guideline 14, which also provides options for a retrofit isolation, whole facility or whole building calibrated simulation approach.

At IES, we would always advocate for a whole building approach as offering the greatest benefits, enabling a deeper understanding of how different retrofit measures are interacting with each other and the existing building. This is where having access to an existing energy model and a robust metering strategy can really come into its own, enabling the creation of a calibrated simulation model or performance digital twin to ensure that the building operates optimally across all parameters, encompassing occupant comfort, carbon and costs, as opposed to considering energy efficiency as an isolated factor.

Recent technology advancements are making this process much more accessible, whilst also enabling the ability to track key performance metrics on a continuous basis, as opposed to reviewing at single points in time. Solutions such as our own IES Live platform enable this next generation approach to building energy, carbon and comfort management. As a cloud-based platform, designed to be delivered by engineering consultants as part of a whole-life building performance approach, it connects near real-time operational building data with daily simulations from a performance digital twin of the building which is hosted online. This enables a single pane view across key building data, highlighting when the building moves away from optimal performance as predicted by the physics-based simulation, and delivering daily insights on the cost, comfort and carbon impacts of customised operational improvement strategies. Results are visualised through intuitive front-end dashboards so building owners, sustainability and facilities teams can see clearly whether retrofit investments have paid off and ensure that they continue to perform optimally over time.

This proactive M&V style approach can be invaluable in flagging any potential issues before they become costly problems. By comparing pre- and post-retrofit data, building operators can validate that the energy savings predicted during the retrofit planning stage are, in fact, being realised, helping to further justify the financial outlay of retrofit projects.

Optimisation needs to be considered a continuous process, with data being fed back into the existing energy model to inform future upgrades and modelling iterations, or to help scale analysis across additional buildings at the portfolio, campus or city scale. Insights gained through this process can be used to benchmark performance across multiple buildings, enabling reliable comparison of different strategies and prioritisation of future investments.

It is important to note that keeping energy models ‘live’ during these intervening years of operation, between different retrofit and refurbishment cycles, can significantly reduce the time and cost outlays on modelling, whilst also unlocking the power of the energy model in operation. This can help project teams to more readily deliver an ongoing performance-based approach to decarbonisation, across the whole lifecycle of any building.

To read more on this subject, download our free guide: Energy Modelling for Retrofit: A Best Practice Approach to Decarbonising Existing Buildings

You can also check out the resources on our Net-Zero Retrofit page or watch our on-demand Energy Modelling & Data Analytics for Net-Zero Retrofit webinar for further insights and recommendations from the IES Consulting team.