05 Making the right decision for non-domestic buildings in carbon and cost terms
5.1 Emissions can be measured in a number of different ways and it is important that the most appropriate carbon assessment methodology is used to ensure decisions about our built environment are made on the basis of a proper understanding of the carbon and cost implications.
5.2 There are strong arguments for the use of a holistic approach to the assessment of buildings whereby sustainability is measured in the round, over the whole life cycle of a building and including the energy involved in its construction and not just in terms of energy usage. Such a holistic approach would take account of the way a particular building behaves in order to avoid inappropriate alterations and to avoid poor decisions when considering carbon impact. As well as the energy performance of individual components, it is important to consider the life cycle of building materials, embodied energy (see paragraph 5.7) and the interaction of moisture, heat and light in a building through heating, ventilation, lighting and use of appliances.
5.3 An appropriate approach is required for all buildings, and perhaps particularly the historic, traditionally built environment, which might be prejudiced by a simplistic energy-usage approach which ignores issues of sustainability and embodied energy, toxicity of materials, the transport of materials and good management practices.
5.4 In our consultation on the Scottish Climate Change Bill, we proposed that targets are specified in terms of "Scottish emissions". Scottish emissions could be defined as the emissions from goods and services produced in Scotland (direct emissions), or emissions from goods and services consumed in Scotland (indirect emissions). Direct emissions form the basis for the Greenhouse Gas Inventories and for existing international emission reduction agreements. However, as part of the global economy, most of the products Scotland consumes are produced outside Scotland. This external production activity also causes emissions, so-called indirect emissions. Such indirect emissions are not reflected in our Scottish Inventory but would be expected to appear in the inventories of other countries.
5.5 In addition to the emissions associated with the production and consumption of goods and services, we also need to consider the energy needed throughout the life of a product or service we consume. This is particularly important for non-domestic buildings which may have a long life.
5.6 Measuring direct emissions only is clearly simpler than using a more holistic approach and in regard to our overall climate change strategy, emission-based targets are a more practical option. However, the particular characteristics of buildings mean that it would be preferable to use a more holistic approach to carbon assessment, where possible, in order to avoid potentially inappropriate decisions either in terms of cost or carbon.
5.7 For example, a new building may require less energy to heat than an old building, but repairing and refurbishing an old building may require less energy and use materials that required less energy to make (known as embodied energy) than building a new building. There will also be carbon emissions associated with demolishing an old building to make way for a new one.
5.8 Where practicable, a carbon footprinting-type approach for use in specific projects and programmes (such as carbon assessment of buildings) would be compatible with, and contribute towards, meeting any statutory emissions targets.
5.9 There are ways under development to measure our overall impact on global emissions from our consumption. The most common of these is the carbon footprint. There are a number of definitions of carbon footprint but the one that is probably the most appropriate for Scotland is:
The carbon footprint is a measure of the exclusive total amount of carbon dioxide emissions that is directly and indirectly caused by an activity or is accumulated over the life stages of a product. 5
5.10 Research is underway to develop a methodology for buildings which can be used for the assessment process. Current methodologies of this kind are not yet sophisticated enough to be used as the basis for a statutory target at this time, but it is hoped that a workable methodology can be developed to encompass the range of criteria relevant to carbon impact from buildings. At present, for new building work, covering embodied energy in building products could fall foul of the EU Construction Products Directive ( CPD). However, the above research is consistent with another one of the Sullivan Report recommendations which advocates 'consideration of embodied energy within construction products in preparation for any possible change in the CPD'.
Q2. Do you agree that we should seek to use a holistic approach to carbon assessment for the built environment when such methodologies are available?
Q3. How should we measure and account for our efforts in so far as they reduce indirect emissions?
5.11 Having set out the important contribution that improving the energy performance of non-domestic buildings can make to our climate change objectives; examining how this links to the Scottish Government's Purpose and the need for an appropriate approach to assessment, this consultation now shifts to consideration of the measures proposed.