Architect’s Corner: Smart Retrofitting
The Key to Decarbonizing the Built Environment
by Nathan Doughty, CEO, Asite
With 80% of the homes that people will inhabit in 2050 already built, and up to 75% of today’s buildings expected to still be in use by 2050, priority must be placed on retrofitting existing buildings, both residential and commercial, at scale to meet energy-saving targets. Simply put, our climate goals cannot be reached without upgrading the existing building stock.
In the United States, of over 135 million dwellings, 59% were constructed before the 1980s and over 76% before 1989. This predates the widespread adoption of model energy codes governing construction. Similar trends are also observed for commercial buildings, with about 54% constructed pre-1980 and 71% pre-1989. These older buildings contribute to exceptionally high energy demands and high levels of greenhouse gases, most of which can be attributed to the burning of fossil fuels for space and water heating and the generation of electricity.
Therefore, to reach zero emissions in the most cost-effective and practical way, it’s crucial that we also lower energy demand and power generation. The Electric Power Research Institute reports energy and energy-related expenditures cost United States companies $800 billion annually, and roughly 42% of the energy used to heat and cool space is wasted. Accelerating efficiency retrofits will ensure that our future building stock is suitable for a zero-carbon economy.
Much of the existing building stock is not well adapted for present or future climates. While much of the wider conversation is future-looking, we must also address current climate-related challenges, such as higher temperatures and flooding. Indoor air quality, relating to a wide variety of pollutants, is also a key concern. While the industry has the capacity and technology to support high thermal efficiency, safe moisture levels, and excellent indoor air quality, an integrated approach to design, build, and retrofit is needed. This pertains to both residential and commercial buildings.
A circular economy is based on the principles of designing out waste and pollution, keeping products and materials in use, and regenerating natural systems to bring clear environmental, social, and economic benefits. These principles, which enable a restorative and regenerative built environment, also drive retrofitting programs. To establish long-term circularity in the built environment, we need quality, open ingredient data on what materials are in a building. Material passports are qualitative and quantitative documentation of the material composition of a building, showing their recycling potential and environmental impact.
To support this, computational technologies, such as BIM and geographical information systems, allow for the modeling and analysis of building stock, in terms of material composition and the creation of a public material register. BIM-based material passports can support the optimization of the retrofitting process. BIM offers a knowledge base for geometry and material properties as well as coupling to further databases for assessment of eco-indicators and recycling potentials.
Smart buildings use a range of technologies, such as sensors and actuators, to gather activity data on elements within a building that can then be analyzed and measured to produce useable insights to automate various processes, such as HVAC systems. Critically, these systems and devices are connected and talk to each other, as well as a central system, to make the building more efficient, reducing its environmental impact. The collection of status, automation, and actionable data means that issues are quickly detected and addressed.
While retrofitting buildings, especially those post-occupancy, poses a much larger challenge than starting from scratch, demolishing properties and replacing them with more sustainable ones is not cost-effective and doesn’t fit with our aspirations to nurture a circular economy that minimizes the impact of building materials and construction processes on the environment. If we are truly committed to operating in an environmentally responsible manner, we must strengthen the implementation of rapid, smart retrofitting strategies globally supported by digital engineering, specifically digital twins.
A digital twin is a combination of resources and information collated on a shared platform, providing a single source of truth for the asset it virtually replicates. This approach utilizes a variety of technologies allowing us to not only achieve our goals, but future-proof our buildings beyond 2050 decarbonization targets. To extract value from the technologies and resources currently available and create a built environment underpinned by resilience and sustainability, the industry needs to operate in a holistic manner with regard to operating and maintaining existing buildings.
Expanding our technical infrastructure to enable data connectivity and a bi-directional flow of information will be necessary to connect real-world assets to digital twins via IoT, sensors, and real-time data. Asite’s mission is to ensure that, as an industry, we can send and receive, capture, share, and collaborate on all the data we are collecting to derive actionable insights to solve global issues.
