Examining Change and Permanence in Traditional Earthen Architecture for Sustainable Restoration
After many years of being overlooked by building professionals and policymakers, vernacular architecture, also known as earthen architecture or adobe architecture, has been recognised for its numerous benefits, including creativity, sustainability, and heritage values. Earthen architecture as a ‘cultural heritage encompasses a much wider set of traditions, practices, skills, and features – some tangible and some intangible’.
Now, this might seem counterintuitive…
The architectural style found in Wa and Tamale, cities in northern Ghana, is renowned for its distinctive use of earthen construction, which features square buildings with flat roofs and circular compounds with conical thatch roofs. Recently, there has been a growing inclination towards the use of alternative construction techniques in which non-traditional materials such as cement, bitumen, and used car engine oil are utilised to render wall surfaces. These structures show how the materials and design in northern Ghana have substantially evolved.
However, what forces drive the changes in cob construction in this region? Furthermore, how might these changes impact the preservation of cultural heritage in Ghana? This study examines the factors that contribute to the departure from traditional earthen building methods that rely on local materials.
https://pencilandpaintmuse.com/Earthen architecture as a building material has been prevalent for millennia, with approximately 30% of the world’s population living in earth-based buildings as of 2015. This percentage increases to 50% in the rural areas of developing countries but decreases to approximately 20% in urban areas. However, by 2021, with rapid urbanisation and population growth, the number of people living in earthen dwellings had decreased to approximately 10% worldwide, with 20–25% in the rural areas of developing countries.
The oldest structures in the tropical savanna zone are earth-based, as this has long been the most widespread construction type. The typical construction techniques for these structures are adobe, wattle and daub, rammed earth, and cob. In Africa, earthen homes are prevalent and feature as a prominent architectural characteristic. These earthen homes are considered cost-effective and environmentally friendly and have excellent thermal performance owing to their thick walls and high thermal mass.
Considering the growing housing shortages in Africa, policymakers and academics have appealed for earth homes to be constructed, as they constitute a promising solution to the low-income housing challenges on the continent. For example, Ugochukwu and Chioma argued that locally produced building materials and intermediate technology can reduce construction costs by approximately 60% for low-cost housing in Nigeria while asserting that the reinvention of local building materials and technologies ‘should not be on the material alone but the methods in which the material and its products are utilised for creating architectural splendour in structures’.
Despite these advantages, there has been a gradual global shift from the use of earth as a construction material to more modern building materials such as cement/concrete, fired brick and tiles, steel panels, and plastics, which are seen as having more benefits. Both technical and social factors underpin this shift from earthen building construction. Notably, earth-based buildings are perceived as vulnerable to earthquakes, tropical storms, major windstorms, and flooding because, traditionally, they are not reinforced, and the roof-tie-down anchorage may be weak.
Ready access to industrialised building technologies and the disdain associated with staying in earth buildings have contributed to the gradual loss of earthen architecture. Other reasons include the desire for modern buildings, urbanisation, the colluding of cultural values, the colonial experience, and Western education. However, this shift from earthen architecture has resulted in a housing deficit, the loss of traditional building skills, the adoption and use of foreign building methods and standards, health challenges, hybrid building styles, and the loss of material cultural heritage.
https://researchonline.ljmu.ac.uk/24150/24/Examining%20change%20and%20permanence%in%20traditional%20earthen%20construction%20and%20preservation%20in%20Ghana%20A%20case%20study%20of%20Tamale%20and%20Wa.pdfTraditional earthen architecture is considered one of Ghana’s material cultural heritages that needs to be preserved by the Ghana Museums and Monuments Board (GMMB). In Ghana’s cultural policy, which was first developed by the Cultural Division of the Ministry of Education and Culture in 1975 as part of the UNESCO convention and reviewed in 2004, earthen architecture was considered a national cultural heritage.
The sites examined in this study are Tamale and Wa in northern Ghana. Tamale is the capital of the northern region of Ghana, with a total population of 716,455 and a total land area of 922 km2. Wa is a fast-growing municipality and the capital of the Upper West region of Ghana, with a total population of 200,672 and a total land area of approximately 580 km2.
https://built-heritage.springeropen.com/articles/10.1186/s43238-024-00165-wTamale and Wa both have guinea savannah woodland vegetation, which consists of short trees and grasses, with shea and dawadawa (African locust bean, parkia biglobosa) trees dominating the vegetation cover. These trees are economically crucial to the area, as most women in cities, especially at their peri-urban interface, engage in shea-butter and dawadawa processing as their primary or secondary livelihood activities. Dawadawa is also the name of a spice that is produced from locust beans.
The transformations occurring in earthen architecture are varied, whereby different architectural styles are mixed in practice. Oyelami and Rooy (2018) argued that using compressed earth bricks is frequently regarded as a second-class building resource for poor and underprivileged people in southwestern Nigeria. The limited acceptance of earthen buildings is also ingrained in how the colonial authority in Ghana has perceived earthen construction as unsafe dwellings.
A constructivist research approach was adopted for this study to provide a better understanding of the underlying drivers of the shift in building material preferences in favour of modern cementitious construction techniques. The data were collected in three phases between May 2021 and April 2022, including a reconnaissance survey, a household survey in Tamale and Wa, and further investigation of participants’ appreciation of indigenous housing construction practices in Wa.
The findings show that the early buildings constructed between the 1970s and 1980s were typically circular shaped with thick cob walls and thatch roofs, which the respondents recognised as a representation of the Dagomba architectural tradition. The newer buildings, which were built after 2000, reflected their appreciation of modernity, with contemporary building materials included in their traditional architecture. The architectural forms of the buildings were modified from circular to rectangular, as rectangular bricks were used in construction.
Additionally, the roofing system transitioned from traditional conical and pyramidal thatch roofs to gable roofs with purlins, rafters, and metal sheets extending over exterior earthen walls. This change was made to increase the protection and performance of exterior walls against heavy rain. Most buildings constructed in the last five years were single units without courtyards, which were associated with the old buildings.
The participants reported that using a cement–sand mixture to plaster wall surfaces prolonged the life span of buildings. However, cement and earth typically do not adhere well to each other, so the cement render peels off, and a new rendering might want to be applied every year. Additionally, moisture accumulates behind the render because the cement render is less permeable than the underlying earth and likely does not include a damp-proof course.
Earthen construction is communal in nature, with local builders commissioned to undertake the project and male children, youth, and elders providing support by mixing, moulding, and carrying the cob to the builder. The elders guide the builder and homeowner to double-check that that the layout follows the prescribed cultural practices. Women also prepare meals, fetch water for construction, and plaster the finished buildings.
The survey respondents disclosed that they had trouble accessing building materials to construct their houses. They explained that they sometimes travel more than 10 km to neighbouring communities to cart laterite for construction. The difficulty in accessing these plants has compelled households to use cement for plastering earth walls, which does not bond well with the underlying material and easily peels off within one year.
Approximately 40% of the respondents in Tamale and Wa had experienced flooding in the past year. The respondents asserted that choked waterways and poor drainage systems in the communities prevented the discharge of floodwater into drains. Others argued that flooding was caused by high-intensity rainfall. When flooding occurs, the base of the unprotected earthen walls becomes damp and weak, which may lead to building collapse.
The findings indicate that both physical and non-physical alterations have occurred in the earthen structures in Wa and Tamale. Evolving social and cultural norms, environmental shifts, challenges in sourcing local building materials, flooding, the need for regular maintenance, and concerns about the comfort of earthen buildings are among the key factors driving changes in construction methods and the gradual erosion of both the tangible and intangible aspects of this heritage.
The loss of this significant cultural heritage would signify the disappearance of the community’s traditions, including the knowledge and expertise passed down through generations related to earthen architectural techniques and planning. Since construction is a communal process, the decline of earthen architectural heritage undermines social unity and communal ties.
The architectural traditions in the two study communities are transitioning from traditional earthen construction to modern designs using cementitious and metal sheet components. This shift is driven by the interactions and trade between the city and its peri-urban areas, resulting in a blend of traditional and contemporary influences.
Preserving earthen buildings as cultural heritage objects can inform efforts towards achieving the United Nations Sustainable Development Goals. Preserving indigenous knowledge and cultural legacy associated with earthen architecture is crucial for human existence, as it represents the diverse customs, habits, and expertise passed down through generations.
While heritage listing and recognition may play a role in preserving earthen structures as cultural heritage, other approaches that might be useful in responding to broader societal shifts include education, instituting training programs, and providing financial incentives to maintain buildings. It is critical to involve community members, elders, women, and youth groups in identifying and preserving earthen structures.
By empowering the community to take ownership of their heritage and identify and recognise the value of their cultural heritage, the attitudes, cultural knowledge, and awareness of the importance of the architectural heritage in the local community can be heightened. The different community groups are responsible for defining and protecting their cultural heritage.
Example: Modern Abstract Painting Series 2024