The main objective of the most critical summit on global climate action, COP26, was to ensure global carbon neutrality by the middle of the century and to limit the temperature increase to 1.5°C.
In September, a counter had appeared in Helsingin Sanomat, indicating how long it would take to reach 1.5 degrees at the current rate: a good eight years. This would mean that the critical point would be reached in 2029, the same year as the last coal power plant in Finland will be closed. The national carbon neutrality target is still five years away, and the EU target is more than two decades away. The counter has since been removed from the website.
Although international conferences have pressed for ambitious emission reduction targets, and climate protection commitments have also been made by the so-called climate bad guys China, India and Australia, there is an urgent need for change. The emphasis must be shifted from enabling change in the future to actually reducing current emissions.
The entire life cycle of buildings must be taken into account
The built environment is a huge source of emissions, from the construction products industry to construction sites and from the oil-fired boilers of individual houses to power plants. The environmental impact of buildings should therefore always be considered throughout the life cycle: What are the emissions of the construction materials? Of the construction site? How much emissions are caused by the use of energy in the building?
It is estimated that in a typical new building with first-class energy efficiency, emissions from construction can account for more than half of the total life cycle emissions of the building. The percentages can fluctuate quite a lot if the life cycle of a building is assumed to be 100 years, or even 200 years, instead of 50 years.
Genuine emission reductions or computational gimmicks?
It is clear that in terms of resource and material efficiency, it would be worthwhile to build buildings that last as long as possible. Existing buildings are rich in untapped resources and their maintenance, renovation and utilisation are of great importance for the climate.
However, extending the calculated life cycle does not reduce emissions, but rather the ratio of emission sources. An overlong life cycle also increases the calculation error margin, as the share of future speculation in the calculation increases.
Emissions calculations are a complex business, and relying on rules of thumb is not very profitable. Instead, calculations must be made for each site by a professional to identify the best design solutions.
Common methodologies for interpreting the results
There are many methods of calculating emissions and, in addition to the results, it is essential for comparison to know what method and what kind of data have been used to obtain the results. In Europe, one of the most common ways of estimating emissions from construction is to use the Level(s) methodology developed by the European Commission. In Finland, the generally used method of the Ministry of the Environment's climate survey is derived from the Level(s) system, differing mainly from the future energy scenarios and impacts outside the life cycle. In addition to these, different calculation methods of environmental certificates are used.
The next time you estimate the emissions from a construction project, remember the following questions: What methodology has been used to estimate emissions? Where did the data on material emissions come from? What future scenarios have been used? Who has produced the emission estimate?
Above all: Have we assessed the option of using an existing building instead of new construction?
leading expert Miisa Tähkänen
Green Building Council Finland
Level(s) – framework
Level(s) is the framework established by the European Commission to determine the level of sustainability of a building. A common tool has been developed to support the use and reporting of the Level(s) framework, which has been translated into Finnish by FIGBC.
Read more and see some of the best examples: LIFE Level(s)