Hitting the zero-carbon target
February 1st 2009

The Government has issued a consultation paper about the ways in which all new non-domestic buildings can achieve zero carbon emissions by 2019. Alan Aldridge, executive director of the Energy Services and Technology Association (ESTA) argues that we need to keep the fundamentals in mind

With 2019 just a decade away, it is important to create a framework within which developers and operators can achieve real zero-carbon buildings.

At the same time, it is equally essential not to adopt an attitude of 'zero carbon at any cost'.This consultation, which is concerned with a political aspiration to achieve [zero-carbon' buildings, runs the risk of achieving the first aim at the price of the second.

Currently, building regulations apply to 'regulated services' so items such as lifts, escalators, etc are not covered. To be truly zero carbon, this energy-consuming equipment needs to be included.While tightening the building regulations will clearly reduce the overall energy requirement, there will still have to be some power supplied to the site, either from on-site renewable sources or from off-site resources.The approach to the options for renewable energy is absolutely critical.

Renewable energy can be supplied in three ways: Building-integrated sources Directly associated sources, delivered by private wire from adjacent or nearby generation Over the Grid.

Previous policy discussions on this issue have concentrated on the first two – to achieve zero-carbon status, renewable energy generation should take place on-site or from directly-associated near-site sources.

But developers have argued that some developments, for example in city centres, could never be zerocarbon under these conditions. So this consultation raises the possibility of grid-supplied energy.

At ESTA we think this would effectively be losing the plot! The overall aim of the move to a lowcarbon economy is to reduce the environmental damage we are causing through our modern hightech lifestyle, of which climate change is the most pressing but by no means the only issue. If plentiful supplies of zero-carbon electricity are available over the normal distribution system, the incentive to reduce consumption is negated.

Zero-carbon must also mean minimum wastage through maximum efficiency.

There is also a cost to the UK of taking our collective eyes off the efficiency issue. Renewable energy is at present a great deal more expensive than fossil-based sources.

So reducing demand allows us to reach our carbon targets at lower cost.Cost must remain part of the equation.

To return to the building regulations:we believe this should in future be framed in such a way that designers are required to achieve the maximum possible carbon reductions bearing in mind the site's aspect, location and all its systems both those that are controlled at present and those that are not.This 'carbon reduction potential' should account for 80% of emissions reductions over a conventional building and only then should any other options – such as grid-supplied renewable energy – be permitted.

One question that we think the consultation has not addressed is whether 'zero carbon' should apply to the design of the building or its operation. In other words, should the building have to register a zero rating on an Energy Performance Certificate (EPC) or on a Display Energy Certificate (DEC).The first measures the emissions of the structure as designed/built but the second records how well it is operated and the emissions (if any) that occur through the actual operation of the building.The first is theoretical, the second is concerned with the real world. ESTA feels that a DEC, being an indicator of real emissions levels, should be the preferred test.

In essence, ESTA believes that the regulations should focus on making buildings as low-carbon as possible – and only at this point using off-site renewables to achieve full zero carbon status.

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