Key decision points throughout a Project's Lifecycle
For architects, navigating through various sustainability tools and concepts can often be challenging without a clear understanding of their connections and hierarchy. That is why this blog post aims to assist designers in clarifying these questions and providing guidance on where to start and what questions to ask.
This post consists of two sections. In our initial post on the guide for climate-conscious architects, we outlined essential terms and perspectives that are vital to grasp before making decisions on a design project. Now, in this second post, we will focus on providing guidelines related to topics that emerge during a project's progression.
Let's delve into some key considerations that an architect should consider by an architecture project:
Decision on the project
It is important to emphasise that by accepting the initial brief, we are already setting the stage for fundamental sustainability decisions. Therefore we have to question the briefing and ask ourselves: Is demolition and new construction truly the best path forward, or could renovation offer a more suitable alternative? These initial choices, often led by the client but heavily influenced by us as architects, carry immense implications for the building's carbon footprint. It is a pivotal moment where we have the power to steer the project towards a more sustainable future.
Moreover, the type of project we choose to undertake is equally critical. As conscientious architects, we bear the responsibility of assessing each inquiry with a keen eye for sustainability. There may be instances where it is necessary to decline certain project opportunities in alignment with our values and commitment to sustainability. In essence, our decisions at the outset of a project ripple through its entire lifecycle, shaping not only the building itself but also its impact on the environment. It is a reminder of the power we hold as architects to drive positive change and build a more sustainable world.
Orientation
Orientation and placing is where it all begins. It is the compass that guides how much sunlight our buildings soak up during winter and how much they shield themselves from the scorching summer rays. A well-oriented building can slash heating energy needs by over a third, while also curbing the excessive heat buildup that demands extra cooling in the summer months.
Massing, generally expressed as the A/V ratio, fundamentally defines the energy balance of the building: it highly influences the internal space’s exposure to the outdoor climate, i.e. how much heat we lose in winter and how much we soak up in summer, which directly impacts our energy needs. The more compact the mass, the less material we use, and the lower our embodied carbon footprint becomes.
Generally speaking, cold and temperate climates endorse more compact and low A/V architecture, however, in some situations, i.e. multi-residential buildings in tropical areas, it makes sense to achieve a higher ‘porosity’ (self-shading and exposure to air movement) embedded in the massing, leading to higher A/V ratios and relatively more ‘envelope area’.
Sustainable design is inherently responsive to the local climate and therefore regional in its character. For local conditions, we can plan sustainably by understanding and utilising the local characteristics - for example, by harnessing the precise knowledge of the sun, wind, and geothermal energy potential of the area, integrating rainwater collection, and using it for irrigation or, if feasible, for flushing toilets.
Spatial Organization
Good spatial connections and the use of transitional spaces is essential for sustainability. Well designed spaces, multifunctional areas or the strong connection between indoor and outdoor do not just enhance living spaces—they also play a crucial role in reducing the overall floor area required, thereby directly impacting the building's carbon footprint. Additionally, spatial organisation also influences the building's energy balance. For example, ensuring proper cross-ventilation is essential. It is important to have windows on two different facades with different orientations, one facing the prevailing wind direction, allowing for effective airflow due to pressure differences when windows are opened. Nighttime cross-ventilation during summer can significantly cool down the building in our climate in Hungary, especially for structures with high thermal mass like brick or reinforced concrete. Moreover, effective spatial organisation is not just about harnessing the elements—it is about adapting to the changing seasons. Ensuring there is a shaded terrace and garden connection for every time of day and every season is of a great value. It is about creating spaces that seamlessly transition with the rhythm of nature, providing comfort and sustainability year-round.
Load bearing structure
In a standard building, the foundation and structural frame typically contribute to about half of the carbon footprint across various stages of its life cycle (from production to disposal). This means that the materials used for these components greatly influence the overall sustainability of the building. Timber structures have the capacity to store approximately 1 ton of CO2 per cubic meter. Additionally, in a circular economy where materials are reused multiple times, the stored CO2 can remain sequestered for extended periods, possibly even centuries before being released back into the atmosphere. Therefore, prioritising timber structures over materials like concrete, reinforced concrete, or steel is essential for reducing carbon emissions. Regulations regarding timber structures are more flexible in some European countries compared to Hungary. We hope to see ongoing revision of the current regulatory regime in the coming years.
Envelope
Facade elements, whether walls or windows, directly influence the energy balance of the building through their thermal insulation values, known as U-values. While windows typically have significantly worse U-values than walls, they can positively impact the energy balance with proper orientation by allowing in solar heat gain during winter. Though poorly oriented windows may also allow excessive solar heat gain during summer, leading to overheating. Therefore, fully glazed surfaces are generally not sustainable. The optimal window-to-wall ratio (WWR) depends on climate and orientation. In Hungarian residential buildings, it is generally advisable to have few and small windows on the north facade, while larger openings combined with appropriate horizontal shading devices are suitable for the south facade. East and west facades WWR may range anywhere between that of south and north, however, it is crucial that effective protection against low-angle solar radiation is consequently used here (e.g. screens, shutters, vegetation, etc.) Appropriate air-tightness is equally important for sustainable envelope design, as uncontrolled air exchange with the outdoors may lead to significant heat losses in the winter and heat gains in the summer.
Materiality
Selecting the right materials is crucial in designing sustainable buildings that minimise their carbon footprint. Which means choosing materials that require less energy for extraction, manufacturing, and transportation and create less carbon emissions and waste helps lower the ecological impact associated with the building process. In our material choices, it is vital to lean towards natural construction resources whenever possible. Think wooden load-bearing structures such as CLT, natural insulation like wood fibre or cellulose, and opt for natural cladding whenever feasible. Check out our latest designs of Júlia, Emília, and Ligetszépe, where we encompass all these materials in our design. In instances where steel or concrete are necessary, consider eco-friendlier alternatives such as recycled steel or concrete with a high recycled content cement.
Mechanical planning
In the realm of sustainable design, the decisions we make in mechanical planning play a pivotal role in shaping energy consumption, and thus the operational carbon footprint of buildings. But what does sustainable mechanical planning entail?
In our opinion, first and foremost, it champions passive solutions, advocating for architectural strategies over mechanical equipment. By delving into the intricacies of local climates and meticulously analysing factors like incoming solar heat gain, we can potentially slash a building's energy requirements by half.
The second step is the use of renewable energy sources. The concept of “buildings as power plants” is not a new one, suggesting that energy can be and should be generated locally. The most accessible way to achieve this is through solar panels. However, the challenge with solar panels in residential buildings is that the energy production profiles do not align with usage patterns meaning that energy storage is often needed when the sun is not shining. Solar panel usage is more sustainable when the surplus energy produced can be fed back into the system and utilised. However, for certain applications, such as large retail stores with high cooling, lighting, and HVAC energy demands, the energy production and usage curves can closely match, eliminating the need for grid feed-in. If feeding surplus energy back into the system is not feasible, various-sized batteries can provide a solution. The drawbacks of batteries include their cost and their significant carbon footprint today. The third and last step involves selecting energy-efficient equipment, which can also cut energy needs by up to half. Considering the educated application of the above guidelines, energy usage of typical new buildings may be reduced by up to 80%.
Details
In the world of construction, often small details matter a lot. Take, for instance, the importance of easily disassembled structures in every scale in the realm of circular building practices. Our Ligetszépe project exemplifies this ethos well. Here, even the foundation can be removed in just one day - soil screws can be unscrewed as easily as they were installed, once the building is dismantled. By opting for easily replaceable components, there is no need for a complete overhaul, resulting in a significantly reduced carbon footprint.
Environment
When it comes to designing spaces, creating environments that seamlessly blend with their surroundings is key. Architects should strive to craft habitats that not only respect but also enhance the natural ecosystems they inhabit. This involves incorporating native flora and fauna into the design while promoting biodiversity and ecological balance. Embracing indigenous landscaping techniques allows for the creation of diverse and dynamic environments that thrive harmoniously with their surroundings. Respecting the natural environment entails several practices aimed at harmonising human habitats with the surrounding ecosystem. This includes creating bird-friendly designs, it involves minimising disruptive nighttime lighting and noise pollution. Additionally, architects can design and maintain habitat features that remain relatively undisturbed by human activity, such as nesting boxes and feeding stations. By incorporating these strategies, architects and landscape architects can play a vital role in promoting biodiversity and ensuring the coexistence of human structures with the natural world. By prioritising these principles, architects can contribute to the preservation of local ecosystems while also providing inhabitants with enriching and sustainable living spaces.
Use
How residents utilise the building also plays a much bigger role in its energy balance than we might think. Without automation, not employing shading devices during summer, keeping windows open in extreme heat, and forgetting to ensure proper cross-ventilation on summer evenings can significantly increase energy consumption. Encouraging occupants to adopt energy-conscious behaviours can further enhance the building's overall sustainability and efficiency.
In essence, sustainable architectural planning is a multifaceted journey—one that demands an extremely holistic approach, innovative thinking, and a steadfast commitment to reducing our environmental impact. We trust that this concise guide can offer valuable insights for you. Also, explore our additional design and build principles that incorporate these ideas. Should you require more detailed sustainability guidance, feel free to get in touch with us. Your sustainable building endeavours matter, and we are here to support you every step of the way.
