Building with the environment in mind

Constructing a house, whether residential or commercial, is a dream to many people in this country. Therefore, acquiring a plot of land and saving enough money to lay the foundation is a step to cherish.

However, before you start building on that land, it is important that you carry out environmental impact assessment of both commercial and residential projects.

This is because the environment affects construction throughout the life time of a building and it also helps to ascertain if you are allowed to construct in a specific area.
Failure to conduct an environmental impact assessment can cause you to incur loses as was the case with Kampala Central Division Mayor Godfrey Nyakaana.

He recently lost an appeal he filed before the Supreme Court challenging the National Environment Management Authority (Nema) for demolishing his house on Plot 8 Plantation Road in Bugolobi, Kampala in 2005. Before the incident, Nyakana had been given 21 days to raze the house and restore the wetland in vain. In his recent ruling, Justice Bart Katureebe said in pulling down Nyakana’s house that was erected in “such a critical wetland, Nema was performing its constitutional mandate.”

Environmental assessment

Environmental impact assessment is a process of evaluating the likely environmental impacts of a proposed project or development. Samson Wako, an architect, says it is important to obtain an environmental assessment report on the construction site before the work begins.

“The National Environmental Management Authority (Nema) has to approve the environmental impact assessment report that has been presented by an environmentalist whom the client hired to assess the site.”

He adds that when Nema does not approve the report and indicates the challenges of the project, the architects go back to the drawing board.

“Nema shows us the additional factors that are required so that the building can be approved and we have to incorporate them in the design. For instance, if we are building a factory and it has waste by-products, Nema will say the waste has to be treated before it can be released into water streams. We will then design a treatment plant as well.”

Christine Namagulu, a creative director and architect, ICPIA, says large construction activity has an impact on the environment, which has to be mitigated.

“If you are building near a road, you have to be aware that the people using the road will be affected by the dust arising from the construction. So you develop measures to minimise that dust.”

Tall buildings in a place where there are only one-story buildings, or buildings that take up an entire acre of land will have a huge impact on the drainage system.
“If the client decides to have hard surfaces outside the building, like tiles, this will impact the water flow,” Namagulu adds.

“When it rains heavily, the water cannot drain into the soil due to the tiles. Fast running water also destroys roads, so an alternative drainage system has to be included in the building plan.”

Carrying out an environmental assessment will definitely push up the cost of construction. However, a higher cost at the beginning will save you exorbitant costs when it comes to repairs and mitigating environmental factors.

Dangerous building materials

Everything that is not natural is hazardous to the environment, because it cannot break down into the soil.

Kaveera
“We have to learn how to minimise the environmental impact by using these materials wisely. For instance, kaveera is harmful to the environment but if used in a good way, there is not harm in them.”

Glass
Glass is one of the most unfriendly materials used in construction. Sunrays going through glass have a more disastrous effect on a person than when they are standing directly in the sun.

“In Europe and the USA, glass is double glazed before it is used in construction,” says Namagulu.
“In some, ultraviolet layers are added to deflect the effect of the sun. In Uganda, enhancing glass is very costly, so most clients opt for plain glass.”

Paint
Paint is a dangerous material if used in small spaces without ventilation. The fumes need to circulate so that they do not affect the painter, thus the need for a well ventilated room.
Paint dust, when scrapped, is dangerous both to the painter and the environment.

Environmental friendly materials

Going natural is the only healthy alternative when building. Some natural products include earth and clay bricks.

Earth bricks
Namagulu says; “Earth bricks are compressed and burnt, and they are quite common in France. However, locally, people think that using earth bricks is a sign of backwardness. This is wrong because one of their advantages is that they keep the space cool or warm, depending on the desired temperature.”

The thermal properties of earth bricks are excellent, especially for residential homes. The earth bricks can retain heat or coldness. On the other hand, earth bricks are non-toxic because the material used is completely natural.
Earth bricks are also sound, mold and fire resistant. In case of a fire outbreak, earthen walls do not burn.
Timber

“Timber is also a good natural product,” Namagulu adds. “When you treat it, it can last a long time.”

The need for soil testing

For large projects like commercial buildings which include apartments and rentals, there is a need to test the soil on its viability to sustain the building being put up.
“Simple structures may not require soil testing but large projects definitely do,” says Wako.

“When building, the higher you go, the deeper the foundation. Various soil types come into contact with the cement and steel used. Some of these soils contain chemicals that can gradually eat away the foundation.”

Namagulu agrees, adding, “If the building is storied and the soil is unstable like in water logged areas, this is a recipe for disaster. Soil tests are what an engineer uses to make calculations about the depth of the foundation and size of columns of the building.”

Unfortunately, because of the added expense a soil test will bring, many building owners choose to circumvent this process. To safeguard his job, an engineer is forced to overestimate the material to be used in construction so that the building does not collapse.

“People should know that with each column an engineer overestimates, the more you pay. If he uses more concrete blocks and steel bars you pay the extra cost of the extra materials used. Ideally, it is cheaper to carry out the soil test.

Minimising pollution

“Ideally, pre-fabrication has to be carried out before commencement of construction,” says Namagulu. “The materials like blocks and bricks are made off-site and then transported to the site.”

When it comes to commercial buildings in town, which are constructed right next to other buildings, vibrations are a hazard to the occupants. An excavation plan has to be filed with KCCA to show how the neighbours will be protected.

“Building sites are visual distractions to road users,” adds Namagulu. “To minimise this, the contractor places iron sheets around the building and green netting to protect the road user from accidents caused by straining to see what kind of building it will be.”

Workers, like masons, painters and plumbers, need to have protective gear to help them perform their work efficiently.

Positioning of the building

When building a house, the direction of the building has an impact on the occupants. In the tropics, the sun rises from the east and sets in the west.

As such, window openings should face north-south to minimise the effect of the sun at its peak.
Wako adds that, “In places, like hospitals, where natural ventilation is preferred more than air conditioning, the position of the building also matters since the windows remain open most of the day.”

Of late, there have been devastating earthquakes in several countries.
As a country, we are lucky that we have not yet faced that kind of destruction yet. However, it is never too late to build with foresight.

For large buildings such as apartments a structural engineer has to be hired to measure the strength of the building that is to be put up.

“The foundation, columns, and skeleton of the structure have to be made to withstand wind loads and earthquakes,” says Wako.
“For tall buildings, we design them so that there are joints at intervals to allow for expansion,” says Namagulu.

“We do not build a continuous wall. A ring beam is also placed around the building to hold it. In any case, the building should be a framed structure in which the bricks just fill up the space.”