Module 8: Low/Net Zero Energy (NZE) Buildings - Vernacular and Sustainable Architecture

Defining Vernacular Architecture

• Definition: Vernacular architecture refers to building practices conducted outside of any academic tradition and without professional guidance. It encompasses a vast variety of building types and construction methods from around the globe, covering both historical and extant structures.

• Context: It represents the majority of buildings and settlements created in pre-industrial societies.

• Core Characteristics:     * Local Needs: Serves immediate, localized requirements.     * Material Constraints: It is limited by the specific materials available in the immediate region.     * Cultural Reflection: It directly reflects the local traditions and cultural practices of its creators.

• Sustainability: Vernacular architecture is, by definition, sustainable because it does not exhaust local resources. If a building is not sustainable or suitable for its local context, it cannot truly be considered vernacular.

Cultural, Material, and Climatic Influences

• Cultural Influences:     * The way of life of the occupants and how they use their shelters significantly influences building forms.     * Functional Layout: Factors such as the size of family units, the sharing of spaces, food preparation methods, and social interaction styles dictate the size and layout of dwellings.     * Aesthetics: Culture influences the appearance of buildings, as occupants often decorate structures according to local customs and beliefs.

• Material Influences:     * The local environment governs construction materials. Regions rich in trees develop wooden vernaculars, while areas lacking wood utilize mud or stone.

• Climatic Influences:     * Control over Form: The macro-climate is one of the most significant influences on vernacular form.     * Cold Climates: Buildings feature high thermal mass or significant amounts of insulation. They are typically sealed to prevent heat loss, with windows being small or non-existent.     * Warm Climates: Structures are built from lighter materials and designed to allow significant cross-ventilation through various openings.     * Continental Climates: Buildings must cope with extreme temperature variations and may be altered seasonally by occupants.     * Precipitation and Flooding: High precipitation leads to specific forms, such as dwellings on stilts in regions prone to frequent flooding or monsoon seasons.

Historical Case Studies of Vernacular Structures

• Roman Insula ($500\,BC$): Developed in ancient Rome for the middle and lower classes; constructed primarily of bricks and concrete.

• Tulou ($17^{th}\,Century$): Originating in southwest China, these were community houses of $3$ to $5$ stories built with thick walls and wood frameworks. A single Tulou could accommodate approximately $50$ families.

• Mudhif/Bayt/Raba ($9^{th}\,Century$): Structures from the Middle Eastern wetlands of Iraq made by knitting Asi or Ihdri.

• Carved Caves ($11^{th}\,Century$): Shelters created by digging into steep cliffs to provide protection from enemy attacks; notable examples include Derinkuyu, Turkey.

• Vardo ($19^{th}\,Century$): A mobile residence equipped with a chimney and highly decorated interiors. These are the historical precursors to modern Mobile-Homes which emerged around the $1950s$.

• Converted Vans/Vanlife ($1970+$): Raised as a modern point of discussion regarding whether such mobile living counts as vernacular architecture and whether it is sustainable.

• Mud-Brick ($8,000\,BC$): Also known as Adobe houses, these structures were used across the Middle East, North Africa, Spain, and by Native Americans.

Passive Cooling Technologies and Behavioral Design

• Windcatchers (Malqaf/Wind Towers):     * Function: Traditional architectural elements used to create cross-ventilation and passive cooling.     * Designs: Variations include unidirectional, bidirectional, and multidirectional designs.     * Application: Widely used in North Africa and West Asia (Iran and Persian Gulf) for over $3,000$ years.     * Mechanism: Wind is drawn down into the interior of the house or through a qanat (underground water channel) to cool the air by convection and evaporation. Stale air/dust is often exhausted on the leeward side.     * Example: Borujerdi House in Kashan, central Iran ($1857$); also found in Yazd (Iran), Dubai (UAE), Doha (Qatar), and Hyderabad.

• Mashrabiya:     * A projecting oriel window enclosed in carved wood latticework, typically on upper floors.     * Used for passive cooling and wind catching; water jars or basins were often placed within the latticework to facilitate evaporative cooling.     * Examples are found in Tunisia and Cairo, Egypt.

• Impluvia:     * In Roman houses, the atrium featured a shallow pool called the impluvium in the center.     * Corresponding to it was the compluvium, an opening in the pitched roof.     * Purpose: Collected and filtered rainwater, provided sunlight, and created airflow and cooling through evaporation.

• Behavior and Design Synergy:     * Ancient Egypt: Damp reeds were hung over windows and water-filled pots placed in hallways to cool air through evaporation.     * Australia ($1950s$): Women in remote areas soaked bed sheets in water and hung them on clotheslines to cool the breeze.     * Moorish Spain: Used trickling fountains and reflecting pools for cooling, alongside deep-set windows for sun protection. Occupants would close blinds at sunrise and open them at night to flush the house with cool air.

Regional Architectural Styles

• Queenslander (Australia - mid $1800s$): A style adapted for the warm climate of Australia.

• Florida Cracker Architecture:     * Designed for the unique Florida environment to promote airflow.     * Examples: Rutland House in Sanibel, Florida, and the Laura (Riding) Jackson Historic House in Vero Beach, Florida.

Modern History and Energy Consumption of Cooling

• Invention of Air Conditioning:     * Willis Carrier: Credited with the modern invention of air conditioning.     * Tampa Theatre ($1942$): The first business in Tampa to install air-conditioning.     * Post-War Expansion: Marketing around $1944$ and $1945$ (e.g., Honeywell and Carrier) advertised AC as the "World of To-morrow," promising it would be cheap enough for private homes and essential for the luxury and health of the postwar home.

• Global Energy Consumption Statistics:     * World Distribution: OECD ($40\%$), U.S. ($20\%$), China ($17\%$), Europe ($16\%$), Russia ($6\%$).     * U.S. Energy Consumption by Sector:         * Buildings: $40\%$ (Residential $22\%$, Commercial $18\%$).         * Industrial: $32\%$.         * Transportation: $28\%$.     * U.S. Building Sector Energy Sources: Coal ($38\%$), Natural Gas ($33\%$), Nuclear ($15\%$), Renewables ($8\%$), Petroleum ($6\%$).

• Air Conditioning Prevalence ($2018$):     * Japan: $\approx 90\%$     * United States: $\approx 90\%$     * Korea: $\approx 85\%$     * Saudi Arabia: $\approx 60\%$     * China: $\approx 60\%$     * Mexico: $\approx 15\%$     * Brazil: $\approx 15\%$     * Indonesia, South Africa, India: < 10\%

• Future Projections:     * Space cooling is the fastest-growing use of energy in buildings.     * The global air conditioner stock is projected to see massive increases through $2050$, particularly in India and China.

Questions & Discussion

• Question: Do you think modern buildings are more sustainable than historical buildings? Why? Why not? What factors influence what modern buildings look like?

• Question: Do you think we have become too reliant on mechanical systems? If so, what are the consequences?