Mr. Kevin O'Rourke:

The average Irish home is responsible today for approximately 6.4 tonnes of CO2. The equivalent figure not too long ago was well over 10 tonnes and at one stage it was 12 tonnes. Therefore, there has been a very dramatic reduction in that respect. The principal reasons for that are related to improved energy performance standards, insulation, better heating and more efficient systems and a switch in fuel to less carbon intensive fuels, most notably from solid fuel to gas, to put it crudely. The third area in this context is that we have had a decarbonisation of our electricity system to a considerable degree.

When it comes to comparison with the UK, the two key determinants are the average age of the housing stock here and the average floor area. Our housing stock is much younger than that of the UK. Our rate of new build during the past 25 years has been much higher than that of the UK and that is reflected in that fact on energy efficiency. Out of 1.7 million homes, more or less a million of them have been built since 1980, which is pretty unusual by international standards. Second, the average floor area of an Irish house is estimated to be about 119 sq. m. compared with 87 sq. m. in the UK, but hot water, lighting and other utilities are used in every house.

The average Irish house at the moment has a superior performance on a per unit floor area basis to the average UK house. On the question of timber frame versus concrete, it is possible to achieve very low-energy buildings with just about any construction method - timber, concrete or even a steel frame. It is a question of the detail in the specification. The issue is the overall functionality. There are factors other than energy, as has been alluded to earlier, which determine the optimum choice.

On the question of near-zero-energy buildings and how close we are to creating them, we were at 300 units to 400 units of energy per dwelling in the 1970s, but now for new-build we are at approximately 60 units of energy. It looks as though going below 50, and certainly going below 40, is a significant challenge. There is not yet a definition at national or European level as to what is near zero but it is fair to say that when one gets below 50 it is close to being near zero and one must start looking at renewable energy to supply that closing balance. We are nearer to it with dwellings than we are with non-domestic buildings. We do have another cycle of the standards review to take place. It is scheduled by our colleagues in the Department of the Environment, Community and Local Government; they will perhaps refer to that.

Cost-optimal is an obligation placed on the national authorities of all member states by the directive on buildings. Essentially, it obliges the member states when they are reviewing their regulations to take a forward-looking, long-term-public-good perspective of 30 years plus when it comes to determining the optimum levels of insulation or any other performance they build into the regulations on the basis that buildings built today are going to have a life of at least 60 years.