Is Fired Clay Brick All We Know?

In this post we carry on the discussion about environmental impacts and wastage associated with the fired clay brick. Owing to the general consensus that it is apparently the cheapest option, the fired clay brick has not left much room for consideration or evaluation of possible alternatives. We acknowledge people’s taste and preference of the fired clay brick; however, suggest that this walling material has become a victim of its own success. Therefore, alternative walling options that challenge this position would have a significant impact on construction practices in general.

Preliminary field evidence shows that contractors, even on large scale projects, generally opt for local artisan made fired clay bricks instead of the more sustainable factory-manufactured options in a bid to save money.  The danger associated with this decision is two fold: on one hand, the inefficient production process continues to strain local wood fuel sources, which contributes to deforestation and air pollution as discussed in the previous post. According to (NEMA 2002: 122), Uganda is experiencing rapid deforestation as to 3% of forest cover is lost per year due to unsustainable harvesting. Worse still, excessive quantities of mortar are used during construction due to rapid construction timelines, inconsistent brick sizes, negligence, and low mason skill levels (Figure 1).  As a result, vast quantities of plaster are required to deliver a smooth finish to these uneven walls. In some situations half-bricks or alucobond are used as cladding perhaps to hide the imperfections, evidence that concern over the cost of the brick was never a well thought through challenge.  Cement wastage in mortar and plaster cannot be ignored since cement production causes pollution and accumulation of waste. Further, according to UNEP (1999), manufacture of cement is the second biggest anthropogenic contributor to greenhouse gas emissions. It is one thing when fired bricks are used on small projects, however the impact is more significant when a noticeable lack of concern is prevalent on larger projects.

Figure 1: Inconsistent brick sizes, unorthodox bonding technique and wasteful application of mortar.

Today’s discussion does not claim to provide a comprehensive solution on material selection since as Sanya (2007) attests, the global discussion embodies the difficult to reconcile aims of safeguarding human wellbeing (including alleviation of poverty) and preservation of the environment. Our discussion here merely sounds out that there are actual viable alternatives to the brick wall. Often times, the argument against alternative construction methods has limited information on cost and performance as compared to conventional methods. However, with more practitioners getting involved in this endeavour toward better buildings, irrefutable evidence of overall gains associated with alternative construction is emerging.

Indeed, production of building materials is an important economic activity. Raw material sourcing, production/manufacture, distribution, marketing and assembly during building construction are all sources of employment. Satisfying the economic need of the local artisans who are currently involved in fired clay brick production is a worthy consideration. As Sanya (2007) puts it, by relating the Ugandan poverty situation to deficiencies in the country’s architecture, the feasibility of the optimistic view that, if economic production is modeled on the sustainable development approach, it is possible to eliminate poverty and improve social conditions while avoiding environmental problems. Much like the fired clay brick makeshift kilns which are some times dedicated to specific projects, these blocks can be commissioned on project-by-project bases and even produced on the construction site on a need basis to minimize wastage. These blocks have low environmental load resulting from use of locally available earth that is not highly refined and use of local resources resulting in affordability and support to the local economy. Also they are adequate for the service life of most buildings. The concept of service life is useful in understanding durability. Service life is the actual period of time during which a building or any of its components performs without unforeseen costs or disruption for maintenance or repair.

Say, we compare fired clay brick with two unfired wall alternatives.  The alternatives include the Compressed Earth Block (CEB) and Compressed Soil Block (CSB). According to Perez (2009), compressing a humid mixture of soil and a stabilising agent in a manual or mechanical press makes the CEB. Note that variations (often in nomenclature) of the CEB include the Compressed Stabilised Earth Block (CSEB) and Stabilised Earth Block (SEB) while those of the CSB includes the Stabilised Soil Block (SSB). In an effort to increase structural stability of the wall as well as reduce bonding mortar, interlocking tongue and groove configurations are being adopted for these unfired earth/soil block options. The Interlocking Compressed Earth Block (ICEB) (Figure 2) and Interlocking Stabilised Soil Block (ISSB) are variations in this regard.

Figure 2: Setup of Interlocking Compressed Earth Block

The CSB is favoured for this discussion because no cement is required during its production.  The CSB indeed is slowly gaining acceptance in everyday construction. CSBs are sturdy and are now being produced in different sizes and configurations to suit the design need. Further still, when an interlocking configuration in ICSB is adopted, no cement is required in the production or construction of the walling as opposed to conventional mortar bonded walls. Also, different soil types may be used together to obtain good CSBs, meaning less demand on clay; this is fortunate because according to (SSA: UHSNET, 2015), good quality clay products are gradually becoming scarce in Uganda. This is due to the limited availability of appropriate clay in the country whose demand has increased dramatically due to high demand associated with an enhanced construction sector. Further, on site production of CSBs means that they are virtually accessible anywhere and mechanically produced blocks can even be delivered with a guaranteed compressive strength and with lower CO2 emission during production. Owing to the high thermal mass of the block, there is an added advantage of cooler interior spaces, which is ideal for tropical climates where cooling governs the energy requirements. CSBs are known to be susceptible to weather damage; however, a resin membrane can be applied onto the walls to improve resistance to moisture.

The second option, the CEB has been used with a significant degree of success in upgrading informal settlements in Uganda (Sanya, 2001). It is highlighted in this post because it represents a modern approach to building with earth in Uganda. While (in a related study at the Uganda Martyrs University) the CSB recorded a higher compressive strength than the CEB, Sanya (2007) also found the CEB more expensive than the fired clay brick wall, however, 30% of this calculated cost was dedicated to cement in the CEB mix. As such, without cement cost for the CSB, the wall type should cost considerably less than the fired clay brick wall.

We conclude that much as cost (and convenience) is what drives most people’s decisions, it is wise while considering the options available for wall construction, to consider a wider selection of factors that indeed will contribute to the combined social, economic and environmental benefits. The focus of our next post therefore will capture specifically how the CEB and CSB in their numerous variations perform alongside other walling options with regard to: Cost, Durability, Aesthetics, Embodied Energy, Site Specific Strategies, Self Build Strategies, Implications for Labour, Technology among other criteria.


Guillaud, H.,Thierry, J., Odul, P.,. (1995) Compressed Earth Blocks. Volume II. Manual of Design and Construction. Eschborn Germany: GTZ.

Sanya, T. (2007), Living in Earth: The Sustainability of Earth Architecture in Uganda, [Doctoral Thesis], The Oslo School of Architecture and Design, Oslo.

SSA: UHSNET, 2015. Challenges of Low Income Earners on accessing building materials. Shelter and Settlement Alternatives: Uganda Human Settlement Network. Viewed on 07.10.2015. Available at: option=com_content&view=article&id=116:building-materials-uganda&catid=83&Itemid=296

Perez, A. (2009) Mission Report, ISSB: Appropriate Earth Technologies in Uganda. Desaster Management Programme. UN Habitat.

UNEP (1999) (United Nations Environment Programme). Dioxin and Furan Inventories: National and Regional Emissions. Geneva: UNEP.



Did German architect Ernst May invent the “Muzigo”?

Ernst May was a German architect and urban designer credited for his contribution towards easing Frankfurt’s housing shortage in the 1920’s and 30’s. So, how is it possible that one credited for fundamental work in one of the worlds greatest cities could have created the symbol of poor housing in Kampala?

Muzigo – name given to single room tennement often found in low-income settlements 

One roomed muzigo - Mbuya  Source: Nnaggenda-Musana & Vestbro (2013)
One roomed muzigo – Mbuya
Source: Nnaggenda-Musana & Vestbro (2013)

In order to understand the connection between May and the “Muzigo,” one has to consider how housing policies in Uganda have impacted stakeholders involved in housing supply. Housing policy in Uganda can be broken down into three phases, pre-colonial, colonial and post-colonial. Before colonialism, the area that currently makes up Uganda was composed of a rural based population of hunter-gatherers and farmers. With exception of the “Kibuga,” – the traditional centre of the Buganda Kingdom, there were no notable urban areas. Housing was the responsibility of individual households. The family head, often helped by neighbours in the construction process, was responsible for housing provision (Sanya in Nnaggenda-Musana & Vestbro, 2013). With the advent of colonialism in 1893, Uganda was declared a protectorate and Entebbe was declared the Capital of the new protectorate. In 1903 the Uganda ordinance was passed; this ordinance gave the Governor the powers to define the boundary of Kampala. This was followed in 1912 by Kampala’s first plan. The plan was intended to control and direct development, however it must be mentioned that it gave priority to upper and middle-class white and/or Asian populations and was therefore focused on Nakasero and old Kampala (UN-Habitat, 2007.)

The indigenous population was largely ignored with the assumption that they would be migrant in nature, commuting from their rural based abodes to work in the urban areas. In 1930 Ernst May generated the first comprehensive plan for Kampala that included settlements for middle and low-income housing for Asian and African populations (Nnaggenda-Musana & Vestbro, 2013.) These settlements were located in Nakawa and Naguru, on the outskirts of the main industrial and commercial areas. The low-income dwellings were intended to provide accommodation for male labourers who it was still assumed would remain migrant in nature.

This is supported by the fact that the spatial nature of the dwellings did not afford living spaces able to house a family. Spatially, the housing provided for a sleeping area and a kitchenette. The units were arranged around a quadrangle where other living activities could take places. Shared bathrooms and toilets were housed in a block off the enclosing units.

Low-income housing unit nakawa Source: Author
Low-income housing unit nakawa
Source: Author


Layout of low-income housing unit - Nakawa Source: Author
Layout of low-income housing unit – Nakawa
Source: Author

May’s low income housing, I theorise, gave rise to the modern day one roomed tenement commonly referred to as “Muzigo.”


UN-Habitat. (2007) Housing for all: The challenge of affordability accessibility and sustainability. Nairobi: UN-Habitat. Nnaggenda-Musana, A., Vestbro, D. U. (2013) Upgrading with densification. Global Journal of Engineering, Design and Technology. Vol.2, no.1, pp. 27-72.

Nnaggenda-Musana, A., Vestbro, D. U. (2013) Upgrading with densification. Global Journal of Engineering, Design and Technology. Vol.2, no.1, pp. 27-72.