An enormous amount of waste is generated in the construction industry. It is estimated that if 1000 tonnes of building material is brought to be used on site, between 200 and 300 tonnes ends up as waste. After a day of work, workers are often not motivated to clear their waste from the site. Knowing how to manage this waste can lead to millions being saved and driving down construction cost. Main construction waste consists of wood cut-offs, POP, blocks/bricks, roofing sheets, ducting, pipes, etc. and these items can go a long way to constitute a nuisance in the long run.

Various steps can be taken to manage waste effectively on a construction site. Designs can be done in ways to reduce potential waste and also effective plans could be made towards waste management during construction.

Avoiding waste during design involves the provision of exact dimensions and sizes of all the components required to build and also a detailed specification of what materials are to be used in order to avoid leaving things to chance.

These details should be provided with construction drawings from the architect. This will allow materials to be able to be planned for and cut to size in the best possible methods. Another way is to design according to sizes of materials available in the market. For example, using the most common building material in Nigeria, 225mm sandcrete block that has a dimension of 225 x 225 x 450, to avoid waste while using these blocks, it will be best to design the spaces in increment to the size of the blocks. This goes for other materials too. If these methods can be utilized, I believe that waste can be anticipated and taken care of before the start of construction.

Window Head and Sill Detail. Source: Rochester Passive House

Waste should be planned for before construction starts. Areas must be set aside for waste disposal with bags or metal bins kept to allow easy sorting of the waste. This may take a reorientation of workers and may require incentives as most workers are conditioned to treat waste with the least amount of care. This will make the waste easier to dispose of and also make recycling possible and easy.

Properly marked waste disposal bins. Source: Realty Plus Magazine

Some materials that are discarded on site actually have a reuse value. It would make sense to keep a reuse pile for cases when this is needed to avoid unnecessary trips to the market. In some renovation projects, things like sinks, counter-tops, showers, etc. can be sold or donated for other people to use.

Furthermore, having waterproof storage on site is a necessity. This will reduce the number of trips to the store and save up on transportation cost. Taking inventory of available materials is also important so you can have a record of what you have around. Excess materials can be sold off or used on subsequent projects.

Elimination of wood waste from concrete work can also be achieved by using modular metal form-work. This will totally remove the use for wood for form-work and can be carried on to subsequent projects. Also, using steel scaffolding instead of the alternative, bamboo. Though these are more expensive, there are safer, and in some cases easier to use.

If these methods are implemented, I’m sure it will make construction sites safer, encourage savings and also free up waste.