Let’s get switched on to operational ratings
Just about everywhere you go in the building-services industry these days, there is much talk about improving the energy efficiency of buildings — and, by implication, carbon emissions. Until fairly recently, the interest was directed at new buildings — prompted by the long-awaited new Building Regulations based on designing buildings to achieve a certain level of carbon emissions. Increasingly, however, the concept of operational ratings is coming to the fore as the message spreads throughout the industry that not only are they much easier to work out than asset ratings but also show how a building is actually performing [see John Field's article on page 15]. Operational ratings can be worked out for existing buildings and provide an immediate method of identifying opportunities for reducing carbon emissions and monitoring the success of resulting action. Operational ratings are seen by the Chartered Institution of Building Services Engineers as the key to improving the existing building stock. With a new building, it takes up to two years from occupation to obtain a reasonable set of energy bills — but those bills should already exist for older buildings. Unless, as CIBSE points out, operational ratings are more widely applied, it will not be possible to measure the performance of up to 98% of the existing building stock. The reality is that exciting though the idea is of every new building being zero carbon, the 20% reduction in carbon emissions that can be achieved very cheaply in existing buildings will have far greater benefits — and much more quickly. Many, many people can contribute to that kind of reduction in carbon emissions — not just those involved with new buildings and major refurbishments. One example is highlighted on page 25 of this issue, where ongoing work by Barnsley Metropolitan Council has already reduced carbon emissions by over 40% compared with 1990. Work continues by developing the use of wood-based fuel to heat community housing to reduce carbon emissions by 60% by 2010. One of the most avid proponents of reducing carbon-dioxide emissions from buildings is Dave Hampton, who stresses elsewhere in this issue that a 25% reduction in carbon emissions every five years from existing building stock is both possible and necessary. Given the will, that is hardly a challenging target — but 25% reduction every five years for 15 years is a cumulative total of almost 60%. Is carbon 60 really such a challenge?