Protecting the planet and ensuring it remains habitable for future generations is the essence of the net zero carbon debate. With this in mind, the net zero carbon school seems an obvious place to start.
Striving for anything less than a net zero carbon school building programme is illogical if we’re talking about protecting future generations. Straight away this agenda bumps up against two difficult questions: how are we measuring net zero, and is it attainable with current technology?
These are questions that Innovaré and our partners in school building programmes are tackling head-on. Together with KLH Sustainability we’ve developed a carbon calculator tool based on the RICS whole life carbon assessment model. Applying the tool to present and future projects ensures that we practice what we preach.
The tool extracts data from the REVIT estimating model to measure the embodied carbon associated with the product and construction process stages. We’ve further developed the system to measure and reduce operational CO2 emissions and provide a closed loop feedback process with our factory.
Embodied Carbon and the Net Zero Carbon School
The critical factor in the calculation is embodied carbon: the greenhouse gas emissions created by extracting, processing and transporting materials and using them in the construction process. The materials and the process have an irreversible carbon footprint.
Balancing out the high levels of embodied carbon associated with concrete, steel, bricks and blockwork means selecting a material with negative levels of embodied carbon emissions for a substantial proportion of the building. In practice this means structural timber, principally within SIPs or CLT structural elements.
The tool produces an accurate figure for the net level of embodied carbon. To achieve ‘cradle to grave’ net zero carbon performance, any deficit will have to be paid back by the building generating a surplus of energy from renewable sources over its lifetime.
Applying the model to a recent new school project (Rockwood Academy), produces an embodied carbon figure of 308.7tonnes CO2e, offset by 195.2tonnes CO2e due to sequestered carbon in the structural timber elements. Substituting timber cassettes for precast concrete flooring reduces the embodied carbon to 268.4 CO2e and increases the offset value to 253.8 CO2e – virtually cancelling out the carbon footprint.
This process is just the start. We know that we can improve net zero carbon performance from project to project when we work with established partners. The carbon measuring tool gives us an objective way to evaluate design choices and drive continuous improvement.
So, to come back to the original questions, the net zero carbon school has to be evaluated over the entire lifecycle to include embodied carbon. And yes, we are confident that net zero can be achieved in practice using current technology. We have the data to prove it.
Find out more about how we work by visiting our resource centre, or email enquiries@innovaresystems.co.uk for more information.
