Embodied Carbon Benchmarking for Low-Carbon Smart Buildings in Saudi Arabia Waqar Hussnain

Every building leaves a carbon footprint long before its doors open to the public. While much attention has focused on the energy a building uses to heat, cool, and light its rooms during its lifetime, a significant portion of its total emissions happens before construction even begins. This hidden cost, known as embodied carbon, comes from the extraction of raw materials, their manufacturing, their transport to the construction site, and the physical act of putting them together. As buildings become more energy-efficient and their operational emissions drop, this upfront carbon burden is becoming a larger share of the total environmental impact. For the Kingdom of Saudi Arabia, where massive new cities and tourism hubs are rising rapidly under the Vision 2030 initiative, understanding and measuring this upfront cost is critical. Without a clear way to measure it, designers and builders cannot effectively reduce it.

In a new study, researcher Waqar Hussnain has taken the first step toward solving this problem for the Kingdom by creating a practical framework to measure and compare the embodied carbon of large-scale commercial buildings. The work addresses a specific gap: while international data exists for buildings in Europe or North America, nothing has been tailored to the unique materials, climate, and construction practices of Saudi Arabia. The study focuses on the "giga-projects" that are reshaping the landscape, such as massive hotels, mixed-use towers, and tourism complexes. By analyzing real project data, the research establishes a set of reference points that allow architects and developers to see how their designs stack up against current standards, best practices, and future goals.

The researcher approached the problem by looking at the life cycle of a building from the very beginning. They defined their scope to cover the period from the extraction of raw materials through to the moment the building is practically complete and ready for use. This timeframe includes the supply of raw materials, their transport to factories, the manufacturing process, the transport to the construction site, and the final installation. The researcher chose this specific window because it is the stage where design decisions have the most direct impact on emissions, and it is the part of the building's life that is most consistently measured in international studies. They excluded the emissions from the building's daily operation and its eventual demolition, focusing instead on the upfront cost of creating the structure itself.

To make the measurements useful, the study used a standard unit of comparison: the amount of carbon dioxide equivalent emitted for every square meter of the building's total floor area. This approach allows for a fair comparison between buildings of different sizes. The data came directly from the detailed material lists, known as bills of quantities, of actual commercial and mixed-use projects currently under development in Saudi Arabia. These lists detailed the massive amounts of concrete and steel used in these structures. The researcher cross-referenced these quantities with existing databases on the carbon intensity of materials, specifically looking at the main ingredients: Portland cement, supplementary materials like fly ash and silica fume, and steel reinforcement.

The study found that while a perfect, locally sourced database of environmental data does not yet exist for every material in the Kingdom, a workable framework can still be built. The researcher proposed a four-tier system to categorize building performance. The first tier sets a minimum acceptable limit, aligned with current building codes. The second tier represents the typical performance of current projects, serving as a baseline for what is happening right now. The third tier reflects best practice, showing what is possible when builders use advanced materials like supplementary cementitious products to reduce the carbon footprint of concrete. The final tier sets an aspirational target, pushing toward the maximum reduction possible in line with the Kingdom's long-term decarbonization ambitions.

One of the key findings is that the specific mix of materials used in Saudi Arabia, which relies heavily on cement, requires its own unique benchmarks rather than simply copying values from other parts of the world. The study highlights that the widespread use of supplementary materials, which can lower the carbon cost of concrete, is already a factor in some projects and should be recognized as a path toward better performance. However, the research also notes a significant hurdle: the lack of detailed environmental data for materials produced locally. Much of the current analysis had to rely on generic data from international databases because specific environmental product declarations for regional materials are still scarce. This introduces a degree of uncertainty, meaning the current benchmarks are a strong starting point but will need refinement as more local data becomes available.

The ultimate goal of this work is to integrate these benchmarks into the national green building rating system, known as Mostadam. By folding these four tiers into the certification process, the study suggests that Saudi Arabia can create a clear, practical pathway for the construction sector to decarbonize. This would move the industry from guessing at performance to having a structured, transparent way to measure progress. The framework offers a way for developers to set concrete targets during the design phase, ensuring that the massive building stock generated by the Vision 2030 giga-projects is built with a lower carbon footprint from the very first day.

While the study does not claim to have solved every data challenge, it provides a vital foundation. It demonstrates that with the right system boundaries and a focus on the materials that matter most, it is possible to create a localized benchmark for the Kingdom's unique construction environment. The work fills a critical void in the global literature, which has historically focused more on residential buildings and different climates. By providing a structure tailored to the commercial and mixed-use typologies that dominate the Saudi giga-project pipeline, this research adds a valuable piece to the global puzzle of building decarbonization. Future work will need to gather more specific data from the region to tighten the accuracy of these numbers, but the framework itself offers a clear, actionable path forward for a greener built environment in the Kingdom.