Affordability is now the key criterion when it comes to commercial heating solutions in 'austerity' Britain. There has been a definite shift in the regulatory framework that places energy efficiency and security of supply ahead of carbon saving. This is clearly reflected in the next set of proposed revisions to Part L of the Building Regulations.

Cutting carbon simply by deploying renewables without addressing overall energy consumption is no longer an option. It makes projects too expensive to deliver and too expensive to run. The whole industry must focus on addressing energy demand first and foremost before considering whether renewables have a role to play.

Ironically, this approach will probably lead to more carbon savings because, by including cost optimisation criteria in line with the recast European Energy Performance of Buildings Directive (EPBD), the industry will be able to tackle more buildings. Thousands of low energy buildings must be better than a handful of 'zero carbon' exemplars.

The directive has set the background in Europe by requiring that all new buildings are to be nearly zero energy by the end of 2020 - all public buildings will need to meet this target two years earlier. This means that targets are now being expressed in terms of kWh/m2 per year - that is energy rather than carbon - and this is the language of engineers rather than politicians. As a result, our targets are now easier to understand - the carbon savings will come as a consequence of buildings becoming more efficient in operation.

The coalition government is trying to create a more 'business friendly' environment around UK regulation so is aiming for measures that are 'effective and proportionate and implemented in a way that minimises the burden on businesses', according to the Department for Energy and Climate Change (DECC). In aiming for affordable solutions, consultation on the new Part L, due to take effect in 2013, describes efficiency targets between 11 and 20 per cent more ambitious than the current version. By 2019, we may well not be at the original zero carbon target, but rather working to targets thought to represent about 50 per cent below the 2006 regulations. This is both sensible and do-able, but it does require a rethink about how renewables fit into our design aims.

In the replacement and refurbishment market, businesses may well be faced with making decisions influenced by the shift in Government strategy identified above and they may find it helpful to have regard to a trio of basic principles that could be called an 'energy hierarchy'.

This involves; first addressing business energy demand, second making building energy use as efficient as possible and third considering the application of alternative energy sources. Broadly speaking, in order to properly assess the energy demand of the building, a business will need to review the purpose for which a building is being used and the equipment, staffing and methodologies necessary to achieve that purpose.

This will enable quantification of not only the potential building energy demand but also the cost of the energy necessary to meet business objectives. This process may highlight changes in systems and practices that could be made to limit energy demand. The accurate measurement of energy use by efficient metering will be an essential requirement as will flexible systems that provide timely response to changing demands. The financial considerations identified will form the benchmark against which future savings can be measured.

Once fundamental business energy demand has been quantified, building energy efficiency should be reviewed. Simple good housekeeping measures, such as only having equipment turned on when it is actually being used and maximising the use of modulating components and efficient metering, can help reduce energy demand. In addition, improved insulation and glazing can help minimize the adverse effect on internal temperatures of cold air penetration and heat loss.

However, in most cases, water and space heating creates by far the greatest energy demand, as research shows this to be responsible for nearly half of a commercial building's carbon emissions. Leading players in the heating industry have established a formidable reputation for proactively introducing energy efficiency solutions and major advances have been made.

The introduction of high efficiency condensing boilers and water heaters are examples of such improvements and these advanced energy efficient solutions, in conjunction with modern control systems, can enable existing inefficient systems to be upgraded or replaced. These internal building environmental concerns are likely to have their own energy use implications, which will need to be factored in to enable total energy demand and cost figures to be assessed.

The third component of the energy hierarchy is the application of LZC (low/zero carbon) solutions. The driving force behind the various government initiatives that encourage such actions is the UK's commitment to reducing carbon emissions and also, most importantly, to reducing energy costs. Using these technologies can be expected to lead to reduced fuel bills, either by a saving brought about by using less energy or by a direct incentive payment or allowance, or indeed in some circumstances by both.

Solar hot water systems have been a notable success, delivering major savings all over the country. Combined heat and power (CHP) and air source, ground source and gas absorption heat pumps are gaining in popularity as practical solutions which can offer genuine savings in energy costs.

The increased energy efficiency, reduced carbon emissions and consequential lower energy bills that can be achieved by applying the principles of the energy hierarchy should be an attractive proposition for businesses of all sizes.

Leading players in the water heating industry are able to provide the knowhow to enable informed choices to be made at a time when austerity is limiting businesses' room for manoeuvre.

// The author is applications manager of Baxi Commercial Division //