One of the simplest and most cost-effective ways of improving a building’s performance (once passive design measures and building fabric have ensured reduced energy load) is to install accessible data monitoring equipment. If reviewed regularly, the data collected can help ensure energy systems are working as expected and if not, determine why. So, what prevents data monitoring equipment from being installed in construction projects?
The perceived additional cost remains a big obstacle, meaning monitoring systems are often ‘value-engineered’ out of projects at construction stage (a reminder that ‘value-engineering’ is not always about achieving best value, but more a way to reduce construction costs!). This will continue to be an issue until clients can be persuaded of the importance of incorporating a robust data monitoring system in their building, how it can provide greater insight and optimisation of a building’s true performance for both energy and cost savings. Data monitoring is a victim of the focus on capital costs in building projects, instead of taking a long term view and considering operational costs over the building’s lifetime, which are much more important in practice, but are often not necessarily understood at design and construction stage.
In its first year of operation, our Active Office consumed 26MWh of electricity – not vastly more than it generated, but enough to prevent it from claiming to be energy positive. Like with most buildings, commissioning continued well into the first year and beyond. However, unlike many buildings, we did install a substantial amount of data monitoring, which enabled us to identify issues that increased the energy consumption in operation from our design estimations. After some fairly simple tweaks, we were able to reduce the annual energy consumption to 23MWh in its second year, a 3MWh saving, and there is still more to do. Changes so far have included installing larger heater batteries in the air-handling units (as originally specified) and adjustments to the time clock operation – not particularly complicated matters, but it was the data that enabled us to identify reasons for excessive energy use, which could then be remedied.
In addition to improving building performance, capturing and analysing data from building energy systems can also be used as evidence to prove or disprove the effectiveness of different systems.
LETI, who have recently become built environment leaders in working towards a zero carbon future for the UK, make suggestions for data capture and disclosure in their Climate Emergency Design Guide:
- Ensure total building energy consumption is metered and recorded securely and reliably
- Submeter renewables, heating fuel and special uses separately
- Carry out an annual Display Energy Certificate (DEC) for non-domestic buildings and include as part of annual reporting
- Upload five years of data to the CarbonBuzz online platform.
DECs (mandated on all public buildings larger than 250m2 since January 2013) display the actual energy performance of a building for 12 months of operation, and rate a building between A and G, where A is highly efficient and G is the least efficient. However, DECs are not mandatory for all buildings and are not commonly displayed.
But displaying energy consumption is also an excellent way of connecting building users to the energy they use and acting as a nudge to change behaviours towards reducing energy consumption.
Perhaps, there should be an even simpler energy display mechanism for all non-residential buildings, akin to the well-recognised Food Hygiene Rating, displayed prominently in catering facilities across the UK. This could be reviewed annually based on actual data from a building and would have the benefit of acting as a quick engagement tool easily recognised by all. It would look something like this:
Similar to a DEC, this would enable the building owner/occupier to review their energy consumption and determine the most appropriate approaches to improve building energy management and building services, thereby reducing energy consumption, energy costs and CO2 emissions.
There are, of course, issues with this. If a building is rated 0 – 2, for instance, it might not be easy to make the necessary improvements, as it may be difficult to trace exactly where the faults lie (unless extensive metering and data capture are incorporated) and, once identified, it could be difficult to put right. Contractual arrangements with project delivery teams tend to stop after the construction defects period, leaving building owners without support. To mitigate this, there would need to be contracts in place with BMS controllers, or a Facilities Manager who has full access to all the systems. But, both of these options come with their own challenges.
The display screen we have in the entrance foyer of our Active Office has proved to be an effective way of increasing occupant engagement and awareness of energy consumption; identifying patterns in energy behaviour; promoting thinking about how to match their demand to the building’s generation, or shifting their energy demand to times of day when grid supplied energy is cheaper or has a low carbon intensity factor. The simple diagrams used to depict the building’s energy consumption and generation provide a clear picture of energy flows, easily understandable to all.
It is our job as designers to influence clients to understand the importance of data capture for improved building performance. If a project budget doesn’t stretch to anything else, incorporating data monitoring equipment should be prioritised, to enable identification of faults and to target areas for improvement in the most cost-effective way, as well as reducing operational carbon.
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