PCR TOOL 8
Participatory Design
Introduction
PCR Tool 5: Learning from the Housing Sector,
describes how housing is produced in varying
contexts. The use of a professional architect to
design a house to a client’s individual specifications
is predominantly reserved for the rich. Most who
purchase housing in the formal sector have their
houses designed by a developer and built by a
contractor, with limited opportunity to influence
the process. These two cases refer to formal urban
housing. With informal housing, both urban and
rural, residents may engage local builders who use
traditional designs. One example of this is in East
Africa, with the “Swahili House”. This generally
contains a central corridor, with rooms on each side
and a veranda to the front. Where housing is built by
residents themselves, or built incrementally, there
may be less thought about the design. Therefore,
when a disaster strikes, it is usually the low-income,
informal housing that suffers the greatest damage.
This is mostly attributed to poor location, poor
construction and maintenance, and low-quality
materials. However, the design may also be to
blame. For a building to be disaster resistant it must
comply with certain rules related to the location of
buildings, their shape, the position of openings,
and their structure. Many architects and engineers
know these rules, but residents and informal
builders frequently do not. Hence the involvement
of architects and engineers in reconstruction is
important. This is no reason to advocate a top-
down reconstruction process, however. Participatory
design brings together residents and professionals,
to ensure that both have a say in how houses are
rebuilt. This not only creates safer housing, but
also ensures that the people’s own resources are
mobilised and contribute effectively. Participatory
design enables residents to stamp their own identity
on their living environment, generating greater
satisfaction and ownership.
Why is design important for building
back better?
A good design can dramatically change the
resilience of a building to disasters. This is
evident in studies of the design and production of
housing in a given location, and disaster-damage
assessments.
In PCR Tool 5: Learning from the housing
sector, we described three predominant housing
production processes and how these influence
disaster performance. Informal housing was
shown to perform worst as a result of underlying
factors, such as poverty and vulnerability, forcing
people to build on risky sites with poor materials
and designs. Some of these factors may change
following a disaster, for example, there may be
temporarily more resources available for housing,
but many factors will remain unchanged and need
to be considered when designing for disaster-
resistance. Fortunately, informal housing does not
always perform badly. Some is designed following
informal traditional rules based on previous disaster
experience; architects or engineers may be able
to identify these features and incorporate them in
reconstruction. For example, following the 2005
earthquake in Pakistan, traditional timber frames,
dhajji dewari, were used based on experience of
their resilience.
In PCR Tool 3: Learning from Disasters, we
explained how damage assessments of housing
following a disaster can help define which designs
and technologies are most disaster resistant.
Studies of the damage caused by earthquakes have
highlighted the most common design weaknesses:
poor site selection,(on slopes prone to landslides
or in plains that suffer from liquefaction); irregular
building shapes; openings too close to corners
or intersections or irregularly distributed; heavy
roofs; absence of horizontal reinforcement and
lintels over openings that do not protrude sideways
sufficiently; poor or absent foundations; weak
bonding, particularly at corners; poor structural
connections; alterations to buildings; and weak
first floors, very open in plan and with overhanging
higher floors. Similar studies after storms point at
the following common design problems: selection
of exposed sites; poor foundations not anchored
strongly to the ground or well connected to the
walls; open verandas or large eaves the wind can
get under to lift the roof; buildings partly on stilts
that can be lifted; poor structural connections and
lack of bracing; low roof pitches that cause the
roof to be sucked off; poor fixing of roof sheets that
can send them flying; openings too near to corners;
openings only on the wind side, with no outlet on
the opposite site; and louvred windows.
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