Carbon neutral buildings - fiction or reality?
Carbon neutral buildings - fiction or reality?
As the building and construction sector is one of the largest contributors to the climate crisis - emitting 39% of all greenhouse gases and accounting 36% of all final energy use – it has great potential of making significant difference in development towards sustainable living and use of resources.
The emissions are generated in three phases during the building life cycle: manufacturing and construction, operation and maintenance, and demolition and reuse of the construction. All these phases have vast potential for improving the current situation, and carbon neutral buildings are feasible, if we are willing to create them.
Currently the largest share of emissions in the Nordics is generated while using the buildings, particularly for heating, electrical appliances and hot water. The demand can be significantly lowered by optimising massing, orientation and shading, and by using efficient insulation, airtight building envelope and energy saving building technology. Renewable sources can be used for any required energy.
The role of structure and embodied carbon increases as we move towards more energy efficient buildings. Wood as renewable material has significant benefit, as the manufacturing process has relatively low carbon footprint, and more importantly it stores the carbon it has taken from the atmosphere, thus potentially compensating the carbon used for the whole building construction. Solid or mass timber structure has the largest carbon storing capacity.
When considering the building afterlife, wooden components have - modular log construction and modular mass timber units in particular - advantages as they typically can be reused with only some modifications as a construction material for another building, thus extending the period of storing the embodied carbon. By recollecting and recycling metal and concrete, the amount of required carbon in production of these materials can be lowered.
Carbon neutral built environment can be created, if we are willing to take a different approach to our standard way of constructing and valuing the many aspects of designed environment. The components, technology and know-how already exist, with clear targets and good collaboration it can be successfully designed.
