Mountainous and high-altitude regions are considered to be among the most fragile ecosystems on Earth. From melting glaciers to land erosion, these environments face mounting threats from climate change, making it imperative to reimagine how architecture and its supporting infrastructure are designed for such places.
The communities settled in mountain ecosystems are especially vulnerable to the impacts of climate change because of their proximity to early symptoms of changing environments and lack of access to adaptive resources and materials. Beyond all poetic aspirations of building and living in mountain environments, it is an urgent challenge to design solutions that properly resist hostile climatic conditions and promote sustainable and safe human settlements in mountainous regions.
In this article, common threads of design are linked through climatic zones by examining specific ecological and social conditions, such as the material demands of snow-covered mountains or the infrastructural needs of construction in remote regions. From adaptive construction techniques to the mitigation of resource scarcity, the future of mountainous environments depends on a unique approach to ecological urbanism and the urgent need for thoughtful, contextual design in the twenty-first century.
Alpine Climates: Expanding Pre-Fabrication Techniques
The alpine climate, referred to as mountain climates or highland climates, is characterized by the temperatures of the region. Typically, the mean temperature of months in the alpine climate zones will not reach above 50 degrees Fahrenheit (10 degrees Celsius), which will bar most species of trees and vegetation from growing. Although this type of climate zone covers a relatively small portion of the Earth's surface, the alpines are widely distributed across every continent. The heavy snowfall, freezing temperatures, and rapid ice formations indicate a short window for construction times and challenges with retaining heat for residents. The built environment of the alpine climate requires a careful approach to designing for survival in extreme weather conditions.
By leveraging heavily insulated materials, steeply pitched roofs, and reinforced structures to handle the snow and wind loads, designers are finding site-specific solutions to surviving the harsh climatic conditions of alpine regions. While solar energy may not always be reliable in these environments, geothermal heating offers a promising alternative for energy sourcing. Such as the cases of the Alpine Shelter and the Outward Bound Micro-cabins, designers anticipated the challenges of construction on site and utilized pre-fabrication strategies to build, furnish, and transport materials to their site. These strategies of construction, energy sourcing, and heat retention not only overcome obstacles but also showcase innovative solutions for high-altitude construction.
Arid Climates: Stabilizing Loose Grounds
Arid climate zones are defined by their lack of precipitation, typically less than 10 inches (25 centimeters) per year. While this definition certainly includes deserts, arid regions are not restricted to landscapes of dunes and canyons. There are many arid landscapes in extremely cold or rocky regions, and in instances of mountainous environments, there are many arid mountains that retain snow and ice during cold seasons. The ecological challenges associated with designing built environments in arid mountain ranges, notably the scarcity of available water, extreme temperature variations between day and night, and cutting winds, create a unique condition for designers to consider resource accessibility and sustainable energy and water consumption strategies for the residents.
Typically, as the arid landscape is composed of loose surface material, one of the greatest threats to construction planning is erosion and the capacity for landslides. Designers tackle these issues through careful site analysis, stabilizing slopes with retaining walls, and terraces, or planting vegetation to anchor the soil. Foundations are reinforced to resist shifting ground, and drainage systems are engineered to channel rainwater away from vulnerable areas, minimizing erosion risks.
Calculated overhangs provide shade from direct sunlight during the hottest parts of the day, reducing indoor temperatures, while the use of thermal mass materials helps create a natural "heat sink" by absorbing excess heat during the day and slowly releasing it at night. Operable windows are strategically placed to facilitate cross-ventilation, drawing in cooler air while expelling warm air, making interiors comfortable without excessive reliance on mechanical systems. To withstand the harsh, arid climate conditions, designers prioritize passive cooling strategies, such as calculated overhangs for shading, thermal mass as a heat sink, and strategically placed operable windows for cross-ventilation cooling. Thermal envelopes and high-performing windows are critical to safe living.
Mediterranean Climates: Leveraging Thermal Mass
The Mediterranean climate zone is defined by the stark contrast of hot, dry summers and cool, wet winters. Geographically located on the western side of the continents, Mediterranean mountain ranges will experience the benefits and challenges of transitioning seasons. Within the year, these high-altitude regions may experience droughts, heatwaves, and limited water supply during the summer, then brace for flooding, rapid frosts, and cutting winds a few months later.
A key design principle in this climate zone is to leverage the use of thermal mass materials, reflective materials, and lightly-colored surfaces on roofs and façades to manage heat during the intense summer months. As lighter colors reflect sunlight rather than absorbing it, buildings are kept cooler and, therefore, reduce the need for artificial cooling. Thermal mass materials slowly absorb heat during the day and release it during cooler periods, helping to moderate indoor temperatures and create a natural buffer to reduce dependence on heating and cooling systems.
Green roofs are appropriate for Mediterranean climates as many types of vegetation thrive in these humid climates. Additionally, this component manages stormwater by absorbing annual rainfall, which is crucial in areas where water sources are unpredictable. Designers who integrate rainwater collection systems into the planning and construction stage can gather clean, dependable water during the rainy months with sloped roofs, catchment systems, and storage tanks.
Subarctic and Boreal Climates: Constructing on Permafrost
Subarctic and boreal mountain climate zones are characterized by their long, harsh winters, short summers, and presence of permafrost, the name for layers of the Earth's surface that remain entirely frozen throughout the year. Design challenges for these climatic zones are centered around plummeting temperatures, low sunlight throughout the year, and anchoring to the frozen layer of permafrost. In many aspects, the mountains of the subarctic climate will align with the characteristics and opportunities of regions of the Alpine climate, but the lack of sunlight and permafrost add a unique challenge to site-specific design strategies.
Constructing on permafrost presents an array of challenges to the designer. As heat from the buildings leaks toward the ground, the frozen ground will begin to thaw, creating shifting foundations and structural instability. To combat this condition, many buildings are elevated on stilts or piles to allow the cold air to circulate underneath and anchor the building deeply into the ground. Special thermal barriers are installed in the floors, foundations, and thermal envelope to retain heat and moisture. The most vulnerable areas of the thermal envelope are the windows and doors, so careful consideration for detailing these elements is critical for a successful building envelope.
Including windows, although difficult to properly insulate in the subarctic climate, is imperative to combat the few hours of sunlight that reach these regions. By strategically including skylights and reflective interior surfaces, the designer will ensure maximum natural light during the summer months. The long, dark winters require artificial lighting, however, the designer can integrate appropriate types of artificial lights that mimic the warmth, color, and patterns of daylight. These strategies ensure that the resident has a high quality of life through sustainable and considerate planning.
Mixed Climate Zones and the Positive Influence of Microclimates
The curated list of climate zones offers a glimpse into the unique climatic, environmental, and ecological conditions of various mountain ranges worldwide. However, a mountain or its surrounding range will rarely be categorized under just one climate zone. Due to their varying slopes, altitudes, orientations, and wind patterns, the microclimates of mountain ranges can vary within a short distance and rapidly shift throughout the time of year or day. Architects, designers, and engineers can leverage their knowledge of specific climate zones to promote safety, comfort, and meaningful sustainability for constructing and living in mountain environments. However, it is critical to note that designing for a site within a mountainous or high-altitude setting will require a holistic and sensitive approach to how climate zones overlap, fluctuate, and transition.
Editor's Note: This article was originally published on September 24, 2024, as part of the ArchDaily Topics: Outdoors and the Built Environment.
