Background Knowledge

Let’s go through some basic information that should be known before starting a construction project. First of all, one must know in what context and at what location the construction will take place. Different locations require different approaches. There is a big difference whether a project is carried out in a rural area or in the midst of a large city, although construction projects in highly urbanized areas are much rarer for these types of projects. What is daily life like and how are the communities at the project site structured?

Different communities have different expectations and needs. Moreover, there are entirely different challenges when the project is in a remote rural region with poor road access and varying access to building materials or expertise. This phase involves a lot of research and one can start by observing typical local building methods. Okay, maybe it requires almost no research, since there is basically just a lot of concrete and cement blocks. In urbanized areas, 99% of all buildings worldwide look like this. However, it is important to recognize this in order to understand how difficult it is to do something differently, if one decides to.

However, there are always exceptions, which are often very region-specific and can serve as a starting point if one wants to try alternative solutions, such as the cost-effective wooden and straw houses in Mozambique or the wooden and raffia palm stilt structures in Ghana. Various traditional mud houses with thatched roofs in Kenya, Burkina Faso, and Malawi show a long tradition of mud construction. It is important to find such examples if you want to look for local craftsmen who are familiar with such building methods.

It is equally important to understand that simple, self-built mud houses – like the ones showed in this photo – collapse almost immediately after completion, often shape the perception of local people regarding mud construction. What does the immediate environment look like? Is it an urbanized area with small lots and very clear property boundaries in already mostly built-up areas? Is it smaller villages and outskirts, areas that are still being developed, but already have adequate infrastructure and road access?

Is it completely remote without infrastructure and with difficult access? Or in a heavily greened area, that requires a close connection to nature? Depending on the region, the realistic risks of natural disasters such as earthquakes and tropical storms must be considered. As can be seen, there are parts of the world that are mostly safe from both and some countries that unfortunately have to fear both. In recent years, the most notable examples of countries that suffered great destruction and needed international aid, were Haiti and Nepal.

These disasters followed by extensive rebuilding and international assistance highlight the need to pay close attention to construction quality. Without minimum standards in construction, newly constructed buildings could be destroyed again within a few decades, nullifying all efforts. The characteristics of the lot, like size, vegetation, slope, determine the possible appearance of the building. A large lot in a rural setting offers more flexibility for the arrangement of buildings. With smaller lots, the design often has to be compact. If there is a risk of flooding, the design should be adjusted accordingly, to mitigate this risk. In densely wooded areas, the building should harmoniously blend in and preserve as much vegetation as possible. And as often emphasized, the size of the lot must be understood precisely, both on paper and in reality.

Materials A field, where some research, especially on-site, is absolutely necessary, particularly when it comes to using alternatives to cement and concrete. A little window shopping, a walk through the local building materials market helps to make new contacts and get a better overview of prices and availability. One should do this patiently and with a smile: it can be quite entertaining. Many sellers expect that purchases are made immediately and may be disappointed if this does not happen, but that is part of the business.

The basic building material is always various types of blocks. There are different factory-made cement blocks of the highest quality, which are usually too expensive to be used in most projects. Then there are the typical homemade blocks made from sand and cement, which are made directly on the construction site and dried in the sun. This way, transportation costs are eliminated. The manufacturing process is simple. A mixture of cement, water and sand is filled into molds and compacted, to shape the blocks.

There are many different shapes and sizes, depending on who makes them and what form is used, but the end results are very similar and usually depend on how much cement is actually used. The blocks are stacked and stored until use. As can be seen here, they can be easily cut, but can also easily fall apart if too little cement is used. Therefore, they should be handled carefully. They have a high compressive strength and once built into walls and plastered, they are stable and durable.

Burnt bricks are another option. Factory-made options can also be purchased but more often they are made in smaller quantities in homemade kilns. Their availability depends on the clay deposits. In countries like Malawi, Mozambique, and Zimbabwe, they are a common building method. The earth mixture is mixed with water, refilled into molds, and left to dry. Then the kilns are filled with the bricks and heated to a very high temperature of over 900 degrees. Although these bricks are of high quality, they contribute to deforestation issues in many countries by using wood as fuel.

Of all the types of blocks shown, the simple, sun-dried clay bricks are the most sustainable alternative. They consist of a similar mixture of sand, clay and water, with fibrous materials like straw, added as binders in some cases. They are not fired or stabilized and therefore have the lowest carbon footprint. Compared to fired bricks, they have a lower compressive strength and are not water-resistant, but when they are used correctly and well supported, they can be an excellent alternative, especially for non-load bearing walls.

Clay bricks are one of the oldest building materials, in use for 10,000 years and exist worldwide in countless forms and variations. A more modern version of clay bricks is the pressed clay blocks with a 3-5% cement content, which stabilizes them. The mixture is again very similar: earth, gravel, sand, silt and clay in various proportions, water and, in this case, cement. They were first introduced in the 1950s in Colombia.

These blocks are then compressed with special machines, which is the most specific part of their production and that requires the availability of these machines, and corresponding maintenance knowledge. Their compressive strength is higher and they are more durable than the basic clay bricks. In this sense, they can be better for load-bearing walls to be used especially in residential architecture with smaller spans. Their water resistance is still a weakness, so they need to be well protected from rain. After compression, they are laid out to dry and can be used after a curing time of 4 weeks.

A completely alternative construction method is to use bamboo as a material for the load-bearing elements. This is of course only possible in countries where specific species of bamboo suitable for construction are available. We will not go into too much detail in this section, but we would like to emphasize, that it represents an amazing and very sustainable alternative to traditional construction techniques. It requires a lot of knowledge and suitable local experts, who have experience with this building method.

Without such support, bamboo construction is very difficult to implement. On the other hand, when bamboo is used solely as cladding, there are many applications and everything is much easier. Bamboo has disadvantages such as susceptibility to insects and fungal infestation and it should receive a lot of attention for appropriate protection.

It is always important to check the wood situation at the construction site, the quality, availability and costs and to adjust the planning accordingly. Wood will usually always be available at construction sites, to be used for formwork or for roof structures. In some countries, such as Ghana or Nigeria, the wood is of very high quality and available at reasonable prices, so that it can actually compete with concrete as a building material.

In other countries, such as Gambia, deforestation is a major problem and it is almost impossible to find wood, which is then only used for high-quality applications such as furniture or doors. Plywood is also commonly used, especially for ceilings and cladding, and is likely imported from China – one of the largest manufacturers of plywood in the world. If there is no wood or it is too expensive, one should rely on the availability of steel profiles. These are then used instead of wood for the roof structure and can even be used for the entire construction. Metal is definitely the preferred material for roofs.

We can pretend that there are alternatives, but in 99% of cases it is about roofing sheets. This video shows Cape Town, but it could be anywhere else in the world. For smaller buildings, a metal roof is usually chosen and the material is almost always imported from countries like China or India. Although prices are often similar, it is important to check thickness and material composition, as these greatly influence the price.

The thickness difference between 0.4 and 0.6 mm is hard to detect, but it greatly affects the strength and Durability of the panels. Here are some theoretical alternatives for roof coverings. Clay tiles may be very common in Europe, but not so much in the countries of the global South. Besides the price, one of the reasons is that such roofs require a slope of at least 17 degrees. Fiber cement sheets are available here and there and they are occasionally seen on roofs.

Their advantage would be sound insulation, but in our experience, it is also very very likely that they contain asbestos, so caution is advised. The only practical alternative is straw, which has a very long tradition as a roofing material. One should always check, whether straw roofs are common in the region where construction is taking place. It is a sustainable building method, but with two limitations. First, it assumes that in the relevant area there is knowledge about this building method, and secondly, it concerns the design. The recommended slopes for this roof are 45 degrees, which is very steep, therefore they are mostly suitable for smaller building forms. Here are some examples from around the world.

It is very common to use a simple, somewhat thicker PVC for sealing, although it is not really the ideal material. A look at the prices for more suitable products in local stores shows why these are often not suitable for simpler projects. The stores that sell tiles are everywhere, but the selection is often very limited and the quality is not the highest. If you are looking for something specific, it may be necessary to walk around a bit. In most cases, what is available can be purchased immediately, while supplies last. Cement and steel dealers are everywhere.

Prices are more or less always similar, as they are influenced by the global market. Differences usually arise due to the quality of the specific cement brands or transportation costs at a particular location. It is advisable to check whether the specified thickness of the steel bars for reinforcement also matches what is actually sold. Sometimes a 10 mm rod is referred to as a 12 mm rod and no one finds that strange. With cement and steel, it may be wise to buy larger quantities in advance, as prices often fluctuate, but almost never lower.

When traveling, one can often discover unique local architecture. This can be a clay mosque or wooden stilt structures, whose walls are made of palm fronds. All of this can point to some local building traditions, which may be utilized to some extent in the new projects. An interesting source of information is, for example, this website, where various examples of indigenous architecture are presented. Of course, there are many similar sources on the internet, that cover other continents.

Resorts, backpacker hostels and similar places are good starting points to see what is possible with various alternative building methods. Here, one can often see quite well, which parts of traditional architecture could be commercially utilized. If something looks interesting and well-made, one can always ask for contacts and connect with people or companies that built it. There, one can always see various building methods like clay, bamboo, wood, straw construction, and superadobe as well as various paving options.

Transportation is one aspect, especially in projects without a contractor, where the NGO is responsible for material procurement should be taken very seriously. This is often not an easy topic and can be very time-consuming. Therefore, every truck you see on the road, is packed to the exterior. At construction sites in remote areas, one should be careful when comparing material prices with those in the nearest cities, as transportation costs are often not included.

The challenges are not limited to costs and fuel prices. Accessibility can also be a serious problem even at a relatively easily accessible construction site. During the rainy season, everything turns to mud, trucks cannot get through, wheels get stuck. Every time a truck successfully delivers something to the site, it can be considered a small victory: most trucks are in poor condition and constantly break down, leading to further delays and problems. Since the construction site depends on the constant delivery of cement, steel, bricks, or sand and gravel, it is advisable to plan realistically, to carefully assess the situation and account for delays and additional costs.

The level of available infrastructure also plays a major role in the implementation of the project. It should be clear from the beginning, what is available and what is not, as well as what the actual needs of the future building are. Is there water or do wells or boreholes need to be drilled, which can incur significant costs? What about rainwater usage and what could it be used for?

Wastewater: What type of septic tank will be used and how will it be emptied? This also depends on decisions about whether dry or flush toilets will be used. Is there electricity and are there plans to connect to the public grid? Or will solar panels be installed, to meet all needs? If so, how and where will they be installed, protected from theft and maintained? All these questions have further implications and bring potentially high costs, so they should be discussed very early. To get a clear picture of the upcoming challenges and opportunities of a project, comprehensive research is necessary. No matter who leads the construction work, it is worthwhile to personally explore the surroundings. This effort simplifies many future conversations and decisions.