Top of the class
Achieving the necessary credits for the top-end BREEAM ratings demands the use of a building energy management system, as Yasar Butt explains.
As the world’s leading and most widely used environmental assessment method for green buildings, the BRE Environmental Assessment Method (BREEAM) has established itself as the benchmark for identifying the measures that have been put in place to enhance energy saving and limit carbon emissions. A BREEAM rating enables the direct comparison of a building’s performance with other rated buildings, as well as the sustainability credentials of non-domestic structures.
The launch of BREEAM 2011 New Construction, or BREEAM 2011 as it is more commonly referred to, on 1 July 2011 was the scheme’s first major change since 2008, when the mandatory post-construction review was introduced.
The most notable feature of the revised scheme was the fact that it assessed new buildings only. Focusing on retail, education, healthcare, industrial and multi-residential, as well as offices, prison and courts, other significant changes included new benchmarks and assessment methodologies for operational carbon emissions. New and updated reporting requirements of key performance indicators, such as building lifecycle CO2 emissions, were also outlined.
There are a number of elements that determine the overall performance of a new construction project. To maintain a flexible system, BREEAM adopts a system of credits that are aligned to particular requirements.
Although most credits can be traded (non-compliance in one area being offset through compliance in another to achieve the target BREEAM rating) to ensure that performance against fundamental environmental issues is not overlooked in the pursuit of a particular rating, BREEAM sets minimum standards in a number of key areas.
These include energy usage and CO2 emissions, and there have been amendments to how these are assessed. The changes have been made alongside the 2010 revisions to Part L of The Building Regulations and associated changes to the NCM Simplified Building Energy Model (SBEM). These form the basis for the revised energy approach and the calibration of performance against a defined scale for energy performance and reduction of CO2 emissions.
With energy control being such a vital ingredient for a high BREEAM rating, architects and designers are looking towards building energy management systems (BEMS) as a way to achieve their objectives.
|A BEMS that is designed to incorporate energy-efficiency best practice will make a significant contribution to minimising CO2 emissions.|
Formed from distributed intelligent controllers linked together via an IT based network, a BEMS offers two major benefits that conventional controls cannot.
First, it provides a continuous feedback of building performance that allows the user to fine tune the operation of the plant.
Second, because a BEMS is software based and almost entirely configurable to the user’s requirements, it ensures an exact fit to the building requirements while offering scope for the application of energy-efficient control techniques.
Just as importantly, it can also record and display energy consumption data, and the information gathered can be used as a tool to target specific problem areas or to automatically control plant on a demand basis. Displaying energy data is highly effective in encouraging the user to take simple but necessary steps to reduce their own energy consumption.
So how much of a contribution could a BEMS make in helping to achieve a high BREEAM rating? Trend Controls recently undertook a study that looked at the BREEAM credits available for different applications in a new build and identified the credits that could be achieved.
The study looked at items such as lighting control, natural ventilation, air quality, thermal comfort, energy sub-metering, water consumption and leak detection. Whereas each of these could achieve around one or two credits each, when it came to assessing the section for ‘reduction of CO2’ it was found that a massive 15 credits could be gained. To put this into perspective, to achieve an ‘Excellent’ rating six credits are required in this section and for an ‘Outstanding’ rating — achieved by less than 1% of new builds — 10 credits are needed.
Across all BREEAM sections, the potential credit total from using a BEMS is 32. Again, considering that a ‘Very good’ rating requires a minimum of 55 credits and an ‘Excellent’ rating needs 70, the benefits of a fully engaged BEMS are clear.
What’s more, these additional credits can also help secure funding for projects, and when it comes to reducing total construction expenditure a fully integrated BEMS can avoid duplicating aspects of the building’s infrastructure while at the same time making life much easier for the design team. Also, the long-term benefits to the building owner/occupier should not be ignored, as not only will they be able to reduce their energy consumption, they will also save money as a result.
The case in favour is clear — a BEMS that is designed to incorporate energy-efficiency best practice will make a significant contribution to minimising CO2 emissions, help achieve compliance to Part L of the Building Regulations and provide the environmental control, energy data and management procedures measured by BREEAM 2011.
Yasar Butt is an energy solutions specialist with Trend Controls.