Henry Burrows, Engineer
The gap gets wider…
In the current climate emergency and drive to lower greenhouse gas emissions, should the energy benchmarks and guidelines for schools be revisited?
New schools being built will have far better performance than existing stock. Total consumption figures are hence expected to be much lower than the current guidelines anticipate, and we should be challenging schools to do even better.
We recently undertook a comparison between actual energy used and the existing BSRIA benchmark figures for predicting how much energy a school will be using.
We discovered that much of the energy usage data that these benchmarks are based on is more than 20 years old and, in some cases, is no longer relevant.
With advances in heating systems and construction techniques, the energy benchmarks appeared pessimistic in comparison to real-world usage today, as 77 percent of schools were beneath the predicted levels.
Modern building techniques and contemporary materials offer better performance than reflected in the existing industry benchmarks. However, 33 percent of schools were still exceeding the energy-use guidelines.
This statistic demonstrates that, despite benchmarks, energy consumption can still exceed expectations significantly. This needs to be considered carefully in the design because, as good as it would be to scale systems back to match a lower energy consumption – some schools are actually using more energy and hence will need to be prepared to cover this.
For future buildings, the design must be interrogated to ensure that this increased consumption is avoided by utilising all efficiencies available.
Whilst the existing guidelines for energy usage in schools are a reasonable initial estimate, they certainly do not represent best practice.
The drive to zero carbon
The energy consumption data for schools is divided into fossil thermal energy (typically from natural gas) and electricity. The benchmarks predict a significantly higher fossil thermal use than electricity, and our study shows that this is indeed the case. But, this has started to shift toward electrical energy (which might be surprising as the data is from existing schools). This will increase dramatically in the near future, as fossil thermal sources are designed out and we head toward the goal of zero carbon.
More electrical power will be required than was originally recognised across the school sector as we continue the drive away from fossil thermal energy sources.
Our study showed that in schools; 62 percent of electricity consumption data exceeded the guidelines for energy use, compared to 31 percent for fossil thermal. This is most likely influenced by heating energy being transferred to electrical sources, and away from fossil thermal, and this gap will only increase. Further to this, electrical appliances and equipment are now a much more significant part of everyday life than they were 20 years ago and this will also contribute to an increased consumption of electricity. This ongoing shift is not reflected or considered by the existing guidelines.
The younger generation are engaged in the climate debate and new school energy benchmarks could be an opportunity for this sector to really make a difference.
While there is a responsibility for schools to manage their consumption, there’s also responsibility on us as designers to make these buildings and systems as efficient as possible. The main drive will come from the building that the schools are presented with and the limitations and benefits this may bring. But, it is also important that we educate people in using and operating the buildings to ensure they can manage the building in the most efficient manner…