Residential and non-residential construction
The results from the carbon footprint calculation model for the chain of residential and non-residential buildings are all too obvious. The largest proportion of the CO₂ emissions are a result of the energy used when the buildings (houses 80% and offices 91%) are in use.
The expectation is that houses and non-residential buildings will in the near future consume considerably less energy. Not only due to stricter legislative requirements (EPC) but also due to the demand from both public and private clients such as investors in real estate.
There is already a range of methods and instruments such as BREEAM and the GreenUp tool that focus on driving down CO₂ emissions in the usage phase.
Incidentally, the greatest energy saving potential can be found in the existing building stock. In the Netherlands, just 1% of the housing stock and 1% of the non-residential buildings are renovated annually. However, the Toolkit Bestaande Bouw (Toolkit Existing Buildings) that was made available by SenterNovem and BAM Woningbouw in November 2008 is being used increasingly often. Due to the extensive nature of the renovation process, the first results are expected at the end of 2009.
Due to the dynamic approach to energy saving in the usage phase, it is expected that the CO₂ emissions of the delivered products will drop strongly in the coming years. As a result, the relationships in the residential and non-residential construction chain will change and the relative share and importance of CO₂ emissions in the procurement and construction phase will rise.
The civil engineering sector concentrates on motorways, railways, civil structures and infrastructure products. The carbon footprint of these projects is completely different to that of residential and non-residential buildings. The CO₂ emissions of railways and motorways are mainly found on the supply side and during the building phase and less in the usage phase. The realisation of products in this sector requires the use of a relatively lot of CO₂-intensive raw materials, such as asphalt concrete, steel and copper. The consumption of these products is low, as road and railway traffic are not included in the calculation model used to determine the carbon footprint.
The attention given to CO₂ reduction is considerably lower than in the residential and non-residential construction sector. This probably also explains the limited number of methods and tools in the area of CO₂ reduction in this sector. Moreover, the tools that are available, including DuboCalc, VPL, URBIS and LEMON, do not target or target to a lesser degree the CO₂ emissions in the procurement and construction phases. It is expected that the central government's sustainable procurement policy, and in particular the policies of the Directorate General of Public Works and Water Management and Prorail, will put CO₂ reduction higher on the agenda in the coming years.
The CO₂ emissions during the procurement phase will also drop in the coming years on the one hand driven by the government's procurement policy and on the other by supplier innovations. As a result, the relationships in the groundwork, road and hydraulic engineering chain will change and the relative share and the importance of CO₂ emissions in the construction phase will rise.