Implenia
2023
Marc Lyon
The whitepaper "Net Zero: How to take the path to net zero carbon buildings," published by Implenia, emphasizes the importance of decarbonizing the building sector, which accounts for approximately 40% of energy consumption and 36% of greenhouse gas emissions globally. It outlines strategies for achieving net zero carbon buildings, highlighting that embodied carbon constitutes about 74% of total lifecycle emissions. Key approaches include efficient design, the use of low-carbon materials, and on-site renewable energy systems. The paper advocates for early planning decisions, such as site selection and compact building shapes, to optimize energy efficiency and reduce emissions. Targets are set for Implenia projects to achieve net zero operational carbon by 2030 for new builds and net zero embodied carbon by 2040. Overall, the document provides valuable guidance for real estate professionals committed to reducing climate impacts through sustainable building practices.
Here is a detailed summary of the whitepaper "Net Zero: How to take the path to net zero carbon buildings":
Overview:
- The whitepaper was published in 2023 by Implenia, a leading international construction and real estate services provider.
- It aims to contribute to a sustainable real estate industry and help meet climate targets by providing guidance on how to develop net zero carbon buildings.
Author:
- The whitepaper was published by Implenia's Real Estate Development division, headquartered in Switzerland.
- The foreword is written by Marc Lyon, Head of Real Estate Development Switzerland at Implenia.
Target Audience:
- Real estate developers, builders, architects, engineers, sustainability experts, policymakers and any stakeholders involved in the real estate sector.
Main Points:
- Buildings account for around 40% of energy consumption and 36% of greenhouse gas emissions globally. Decarbonizing the building sector is crucial to meet climate goals.
- Net zero carbon buildings have very low operational emissions from energy use, low embodied emissions from materials, and any remaining emissions are offset.
- A net zero carbon building typically has high energy efficiency, renewable energy systems like solar PV, a high share of low-carbon construction materials, and offsets for residual emissions.
- Most emissions come from materials and construction (upfront embodied carbon), not operational energy use. Upfront carbon is about 70-75% of total lifecycle emissions.
- Key strategies include: efficient design, renewable energy, passive design, low-carbon materials, and offsets.
- Decarbonization should be considered early, starting with site selection. Compact building design, orientation, glazing, and other early decisions impact emissions.
- Benchmarks help gauge where a building stands on embodied and operational carbon. More ambitious targets are needed to reach net zero.
- Multiple approaches are needed to reduce carbon across the full lifecycle. No single solution will get to net zero.
In summary, the whitepaper makes a strong case for net zero carbon buildings and provides practical guidance grounded in lifecycle assessment and real projects. The intended audience is real estate professionals looking to reduce the climate impacts of buildings.
Key takeaways from the white paper on achieving net zero carbon buildings:
- Embodied carbon makes up around 74% of a building's total lifecycle emissions, while operational carbon is only 26%. There is significant decarbonization potential in reducing embodied carbon through materials selection and construction methods.
- The most effective levers for reducing carbon are in the early planning and design stages, starting with site selection and analysis of access to renewables, compactness, and passive cooling potential.
- Compact building shapes have lower heating demand and embodied carbon per square meter than less compact shapes.
- On-site renewable energy generation, especially photovoltaics, is critical for net zero operational carbon. Orientation, tilt angle, and storage should be optimized for self-consumption.
- Purchasing 100% renewable electricity further reduces operational carbon. Green leases can secure renewable supply.
- Natural shading, ventilation, thermal mass, and green roofs/facades passively reduce cooling loads and the urban heat island effect.
- Targets are set for Implenia projects to reach net zero operational carbon by 2030 (new builds) or 2050 (refurbishments), and net zero embodied carbon by 2040 (new builds).
- A combination of strategies across all lifecycle phases, from planning through operation, is needed to achieve net zero carbon buildings. The earlier the focus, the greater the impact.