Construction Professionals Understanding of Benefit of Stabilised Earth Construction in Urban Low-Cost Housing Crisis in Zimbabwe
Mohammad Sharif Zami*
Department of Architecture, King Fahd University of Petroleum & Minerals, Saudi Arabia
Submission: August 20, 2018;Published: September 06, 2018
*Corresponding Author: Mohammad Sharif Zami, Department of Architecture, King Fahd University of Petroleum & Minerals, Saudi Arabia;
Tel: 9.66567E+11; Email: firstname.lastname@example.org
How to cite this article: Mohammad Sharif Zami. Construction Professionals Understanding of Benefit of Stabilised Earth Construction in Urban Low-
Cost Housing Crisis in Zimbabwe. Civil Eng Res J. 2018; 6(3): 555687. DOI:10.19080/CERJ.2018.06.555687
Stabilised earth is an alternative construction material which is economically and environmentally beneficial compared to the conventional material such as baked brick and concrete. Earth is used as a construction material in every continent since the earliest civilisation. Existing literature shows that the use of earth as a building material saves cost, time, energy, and reduces environmental pollution. This paper critically reviews the literatures and come up with a generic list of benefits of earth construction. A series of in-depth interviews then investigate and ascertain from the Zimbabwean construction professionals whether stabilised earth construction is beneficial in in urban low-cost housing in Zimbabwe.
A number of Delphi and In-depth interviews with earth construction experts carried out by the author in 2008 reveals that some experts do not at all support the promotion of stabilised earth construction as they generally perceive, stabilised earth construction means cement stabilised earth construction. In spite of the fact that stabilised earth is a low energy alternative and could be cost effective in many situations, its accessibility to the rural/ urban poor is far from satisfactory; and while stabilised earth construction is less costly than brick masonry, it is still often more expensive than what the majority of the poor can afford . Besides, it is unfortunate that many practitioners of systematic stabilisation do not know, or do not appreciate the original characteristics of a soil and start about stabilising soil with undue haste when it is not particularly useful . In addition, the majority of disadvantages (i.e. problems of earth wall erosion by rain and flood water, rodents making holes in wall and floor, and poor performance during earthquakes) associated with mud houses (un-stabilised earth) can be overcome by suitable improvements in design and technology, such as soil stabilisation, appropriate architecture, and improvement in structural techniques . It is also noted that, the definition and meaning of stabilised earth construction is understood wrongly amongst the earth construction professionals and experts [4-5]. This paper aims to explore the benefit of stabilised earth construction in Zimbabwean urban low-cost housing context. Furthermore, to achieve the aim, the author critically reviews relevant literature and adopts the in-depth interview method to analyse and validate the benefits of stabilised earth construction in Zimbabwe urban low-cost housing. The following section reviews the current state of art review of benefits of stabilised earth construction to establish a base for the in-depth interviews as to compare and contrast the literature against Zimbabwean construction professional perspectives.
After a critical review of the literatures, it appears that there
is a lack of structured research to date carried out to identify
the benefits of stabilised earth construction in Zimbabwe. In
addition, the benefits identified by different practitioners and
researchers mentioned in the literature lack empirical data
and validation through a research methodological process.
The benefits found in the literature are written in the light of
the researchers experience and perception working with this
building material. Therefore, the research technique adopted in
this paper is in-depth interviews which effectively collects data
from Zimbabwean construction professionals and compare the
list of benefits found in the existing literature.
In order to understand the benefits, the in-depth interview
method unlocked the vital experiences of the experts
represented by the practitioners, academics and researchers.
The aim of a researcher should be to ensure that the method
used enable maximum convergence (transfer of meaning)
between themselves and the respondent . In Loosemore’s
 opinion, interviews are able to facilitate feedback through
two-way communication. Interviews represent a powerful tool
in the building of a theory, not only by eliciting perceptions of
the concept from the experts, that is the industrial practitioners,
but also, the theory-building process is supplemented by
the contextualised data gathered from the stories of the
practitioners’ experiences . The study of this paper executed
in-depth interviews with experts who are experienced in the
Zimbabwean construction industry.
Analysing in-depth interviews involves reviewing the
records of the interviews and taking notes to keep track of the
findings that are emerging and the two most common strategies
for organising notes are: - Organising by question and theme.
Both strategies may be used concurrently; for example, content
analysis can be begun by organising by question, but switch to
a thematic strategy as themes emerge over the course of the
interviews . The researcher of this study used both strategies
concurrently to analyse the data. In-depth interviews are flexible
in that they can be presented in many ways; there is no specific
format to follow .
Boyce & Neale  stated that providing quotes from
respondents throughout the report adds credibility to the
information. The researcher should be careful that the respondent
is not identified or provide quotes that are easily traced back to
an individual, especially if confidentiality is promised. In-depth
interview data can be displayed in tables, boxes, and figures to
make it easier to read. The aim of the in-depth interview is to
refine and validate the generic list of benefits derived from the
literature review considering Zimbabwean context. The benefits
refined by the in-depth interviews are based on the opinions
of the Zimbabwean construction professionals and lead to an
understanding of the benefits of stabilised earth construction in
Zimbabwe. It is worth mentioning here that there are very few
Zimbabwean earth construction experts whom have worked
or are at present working in Zimbabwe. Therefore, in essence,
data was collected through face to face interviews with four
experts and telephone conversations with four more experts.
The political and economic problems of Zimbabwe drove away
most of the experienced and qualified Zimbabwean construction
professionals to the neighbouring countries and other developed
countries. Therefore, conducting the interviews in Zimbabwe
was not possible as the majority of experienced construction
professionals had migrated.
A total of fourteen (14) experts were contacted through
email. Telephone calls were made to follow up the invitation
of the experts to take part in the interview. Eight (08) experts
agreed to take part in the interview pertaining to this study.
Three (03) of the experts were academician researchers with
an average of over thirty years work experience. The remaining
five (05) experts were practitioners with an average of eight
years practical experience. In choosing experts for this in-depth
interview, a set of criteria were considered and accordingly a list
of eight (08) experts were identified from the private and public sector that would have the required knowledge and experience
of the subject.
At first, all experts were asked independently without
informing them of the generic list of benefits identified from the
literature review whether or not stabilised earth construction is
beneficial in Zimbabwe. Interviewees were given this opportunity
to express their own opinions and list the benefits other than
the ones to be validated. Two experts thought that stabilised
earth construction is beneficial upon certain conditions (see
Table 2). Therefore, the broad answer is ‘yes’ but it is project
specific. One must ask what the potential benefits are, and these
have to be weighed against what the alternatives are and what
the particular economic problems the country is experiencing
at the moment are. According to one of the experts primarily
the biggest driver in terms of the benefit of earth building in
Zimbabwe would have to be the cost as he stated that, “If one
can’t afford it in Zimbabwe nobody is going to use it. Therefore,
the economic benefit of earth construction has to be the major
benefit of this technology in Zimbabwe, and as well as a major
part of the developing countries, where labour is relatively
affordable and cheap.” Summary, of the conditions upon which
the stabilised earth construction in Zimbabwe is beneficial are
summarised and displayed in Table 2.
According to experts un-stabilised earth construction gives
rise to a lot of benefits whereas stabilised earth construction
brings very few, if any, as expert states, “the major issue with
urban housing procurement and construction is funding, as it
all comes down to the cost of industrial inputs. People simply
cannot afford cement; therefore, if cement is added into a product
then immediately it runs into all the same problems that urban
housing in Zimbabwe has.” According to expert, most places in
Zimbabwe have sui Table 3 soil for stabilised earth construction.
Moreover, expert stated that, “the rural population always wish
to build with brick, concrete and upgrade their way of living.
Nevertheless, if one can persuade them that earth is an acceptable
building material from the social point of view then they are
already familiar with it. If their understandable reservations
can be overcome, their traditional familiarity with this material
will enable them to use it with skill”. The statements supported
that the suitable soil and local skill set of earth construction are
available in Zimbabwe. Five experts unanimously agreed that
stabilised earth construction is beneficial in Zimbabwean urban
Experts were then shown the generic list of benefits
identified from the literature review and were asked to validate
whether those benefits of stabilised earth construction were
applicable in Zimbabwean urban low-cost housing. All experts
agreed and validated that the list of benefits shown to them
as benefits of stabilised earth construction except benefits
10 and 11 (Table 1) because these need to be backed by more
empirical evidence. According to expert’s air pollution is not a
big threat in Zimbabwe and the production of earth building
material consumes less energy and has minimal environmental
effects, therefore, the benefits ‘10’ and ‘11’ are not necessary in a
Zimbabwean context. The summary of the benefits validated by
the in-depth experts is listed in Table 2.
1. Zimbabwean local culture, heritage, and material.
2. It encourages self-help construction.
3. Earth is available in large quantities in most regions in
In the in-depth interviews it was found that stabilised
earth construction is beneficial in urban low-cost housing but
dependent upon certain conditions and circumstances. It is
notable that the conditions identified in the literature review are
causes only for cost variations of stabilised earth construction.
The conditions and circumstances upon which the benefits are
dependent identified in literature review and in-depth interview
are summarised and shown in Table 3.
Therefore, the above conditions and circumstances in
Table 3 need to be considered to assess the benefits of any
stabilised earth construction project in Zimbabwean urban lowcost
housing. It is important to note that the literature review
identified fifteen (15) benefits and in-depth interview identified
thirteen (13) benefits of stabilised earth construction in housing.
According to the majority of experts, the economic benefit has
become the major benefit of this technology in Zimbabwe as
well as a major part of the developing countries where labour is
relatively affordable and cheap [10-27].
The construction professionals participated in the indepth
interview agreed that stabilised earth construction in
Zimbabwe urban low-cost housing is beneficial dependent on
some conditions and circumstances. Therefore, if the typologies
of urban housing, availability of the suitable soil locally sourced,
appropriate climatic conditions, the typologies of stabilizer are
appropriate for this kind of construction, then stabilised earth
construction is beneficial building urban low-cost housing in
Zimbabwe. The use of earth as a construction material with an
innovative approach would apply well and can be considered
as a sustainable solution to the urban low-cost housing
crisis. Promotion and adoption of earth as an alternative lowcost
urban house construction material is worthwhile and
significantly helpful in achieving environmental sustainability
(less carbon dioxide emission and less energy used) and reducing
construction cost. Besides, in earth construction individuals and
community as a whole can easily participate in building their
own homes in an affordable way.