Factors Contributing to Construction
Waste Generation
Generally, the factors contributing to construction
waste generation vary depending on the size
of the project, related activities, and project
locations and may arise from the beginning of the
construction process such as site clearing, through
to project handover. The causes or sources of
waste on building projects can be broadly divided
into two groups: work processes and poor material
handling in non-working phases.
Work processes leading to waste generation
may be due to inadequate or insufficient skilled
labour such as plasterers. On the other hand,
waste from poor material handling can arise from
damage and loss of material due to poor design,
transportation, storage, and other material
handling processes. Significant factors that
contribute to construction waste generation are
as follows:
1. Design,
2. Procurement,
3. Construction Methods,
4. Labour and Human Behaviour,
5. Equipment,
6. Materials,
7. Owners.
8. Projects, and
9. Weather.
By analysing the contributing factors listed
above and clustering them into four main
categories; it is estimated that 33% of construction
waste arises from design decisions and this has
become a major cause of waste produced during
construction. Construction is a labour-intensive
industry. Therefore, the actions and behaviour of
construction workers have a significant influence on
waste produced on-site. A successful construction
waste management minimisation approach in
a project, relies on the involvement and changes
in behaviour and workers’ attitudes. Architects,
managers, and workers are likely to be important in
the effective management of construction waste,
and the experience of these people in managing
or eliminating certain waste generation factors is
valuable. Other residual factors are:
● conversion of waste from cutting
uneconomical shapes,
● off-cuts from cutting materials to length,
● over mixing of materials for wet trades due
to a lack of knowledge of requirements,
● waste from application process and
packaging,
● waste due to damage or theft,
● lack of on-site material control, and
● no waste management plan.
The sources categorised differ in terms of
the volume of waste produced; locations, and
the types of waste generated, the management
practices used and the fragmented responsibility
for waste control that was used should be
included in every study. More specific causes
and influences of a refurbishment waste project
need to be identified because refurbishment work
creates higher waste than new constructions.
To address the above, a semi-structured survey
involving 30 respondents among contractors,
construction workers, sub-contractors and the
client/house owners was conducted at 11 ongoing
refurbishment projects in the Klang Valley
where various types of refurbishment work
activities were being undertaken. Using data from
the survey, the Relative Important Index (RII) was
calculated. The RII was used to classify the causes
or factors of refurbishment work activities by rank
leading to the generation of on-site refurbishment
waste. The higher the RII value means higher
ranking.
Where:
Relative Important Index Equation
RII = ∑ w
AN
● w is the weighting given to each factor by
the respondent, ranging from 1 to 5 in
which “1” is the least important and “5” is
the most important;
● A is the highest weight which is “5” in this
study;
● N is the total number of samples; and
● RII is the relative important index,
0 ≤ RII ≥ 1; the higher the index value
means the higher the ranking.
There are two primary sources of on-site waste
generation as illustrated in Figure 1; waste from
demolition and new building activities and waste
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