Cut costs with a plastic bottle house

By Job Bwire and Arithea Nakiwala

For generations now, baked bricks, tiles, concrete and rocks, among other construction materials, have been essentials in construction. But did you know that a house constructed using plastic bottles can save you more and be just as strong or even stronger than brick homes? Water bottle housing is an innovation aimed at providing low cost housing, while contributing to environment management.
 
Construction materials

Bottle walls may be made from non-recycled plastic water bottles. Although bottle walls can be constructed in many different ways, they are typically made on a foundation that is set into a trench in the earth to add stability to the wall.

The trench is filled with rubble of pea gravel and then filled with cement. Rebar can be set into the foundation to add structural integrity. Bottle walls can be one or two bottles thick.

According to Mogen Andersen, a construction engineer with Joint Energy and Environment Projects (JEEP), primitive mixture, such as cob or adobe can be used as mortar to bind the bottles. “It is spread thickly on one layer of bottles followed by the next layer which is pressed into the mixture.

Typically two fingers of separation are used for spacing, although any kind of spacing can be achieved,” he says. Bottles can also be joined together with duct  taped to create a window-type effect.

Two similar-size bottles can be taped together, with the openings acting as light passage ways. This also traps air and creates some insulation. “Filling the bottle with liquid that will be subjected to freezing and thawing is not a good idea, but is useful if the bottle is protected from temperature extremes,” Andersen adds.

The water bottles are packed tight with moist soil and compacted. A string is then tied from the fi rst bottle to the last one
and then stacked upon one another, held together with cement. “It is the same concept of brick buildings, without the fumes, and allows the use of a resource (plastic bottles) that is readily and cheaply available on the roadsides,” he argued.

Binding Mixtures

A typical mortar mix is 3:1 mason sand to a pozzalan (fl y ash) cement mix. Other mixtures could be made from mortar and clay, adobe, cob, sand or cement. Bottle walls are extremely versatile and can be bonded with pretty much anything that can endure any given climate.

Advantages

Cost effective: Building  with bottles is typically less expensive than building with bricks, as the main construction material is trash. In Uganda, many individuals earn money by salvaging used bottles and reselling them on street corners for use in packaging other products like honey or oil.

Purchasing bottles from such vendors is significantly less expensive than buying bricks and essentially funds a grassroots recycling campaign in the absence of a government instituted waste management system.

Waste management: In areas where tap water is unsafe for drinking, bottled water is quite common, particularly at conferences, parties and gatherings. A small house can use as many as 10,000 bottles, waste that would otherwise be deposited in a landfi ll or burned.

Environmental protection: Unlike “traditional” bricks, bottles are not burnt, a process which uses a lot of firewood and  contributes to deforestation.

Job creation: The construction process is work intensive. This means many people would be involved, creating opportunities for employment, from collecting, to fi lling, to building. While this method would potentially be costly in more industrialised nations, where labour is expensive and materials are cheap, in countries like Uganda, materials are expensive, labour is cheap,  and unemployment is high.

Shock resistant: The plastic coating of “bottle bricks” makes them more flexible than fired bricks. Bottle construction has  reater shock resistance and is bettersuited to earthquake prone areas.

Long lasting: It is estimated that a plastic bottle takes approximately 300 years to decompose. When the bottles are filled with moist soil or other dark material, the wall can function as a thermal mass, absorbing solar radiation during the day and radiating it back into the atmosphere at night.

The bottoms of the bottles, poking through the concrete, have a whimsical aesthetic to them. The tops of the bottles, visible on the inside, can also make for built-in interior decor. A demonstration house of this kind was built at the  JEEP Folk Centre in Kyanja, Nakawa Division, Kampala. It is 8x7ft wide and 10 feet long.

A total of 663 plastic bottles were collected and used in the construction of the house, according to Ruth Kiwanuka, the CEO JEEP. It cost sh2m, including labor and materials. There was also a 1.5l plastic soda bottle stuck in the middle of roof to give light. The bottle in the roof was filled with water and chlorine and covered. It reflects light from the sun during day and from the moon at night to provide some light.

According to Rachael Turyamuhebwa, a training manager with JEEP, unlike a brick house that requires a lot of tree cutting for burning bricks, the bottle house is environmentally friendly. “It is one of the best soil fertility and waste management practices, because most water companies do not collect used bottles for recycling,” she says.

Andersen argues that the bottle house is just as strong or even stronger than an ordinary brick house. “Filling the bottles with  oil is a task that even children can master and does not present a potential danger such as the fumes and the heat of fusing bricks. Besides, the water bottle walls provide higher quality insulation than brick walls,” he adds.

A brief history of plastic bottle houses

The first plastic bottle construction project in Africa was pioneered in Uganda by Butakoola Village Association for Development (BUVAD) in 2010 in Kayunga district.

The idea followed a BUVAD community survey in 2009 that revealed that many farmers in  Kayunga were experiencing low crop yields due to poor soil fertility, which was a result of the presence of waste plastics, such as bottles and polythene bags, in the soil.

It is believed that the first bottle house was constructed in 1902 by William F. Peck in Tonopah, Nevada. The house was built with 10,000 bottles of beer from Jhostetter’s Stomach Bitters, which were 90% alcohol and 10% opium. The Peck house was demolished in the early 1980s.

The use of empty vessels in construction dates back to ancient Rome, which had structures with empty amphorae embedded in concrete. This was not done for aesthetic reasons, but to lighten the load of upper levels of structures, and to reduce concrete usage.