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A recent study undertaken by Dublin City Council could serve to shatter many commonly held misconceptions about how existing buildings can perform when compared to new build, even simply just in terms of running costs.
Over the following pages Donncha O’Dulaing, Heritage Officer with Dublin City Council, takes us through the surprising and often illuminating results of the study which compares five existing buildings from economic, environmental and cultural perspectives.
The
retention, rehabilitation and reuse of older buildings can
play a pivotal role in the sustainable development of Dublin
City. The city contains many examples of buildings, which,
though not protected, have artistic, architectural or historic
merit. Many of the buildings are attractively designed, have
stood the test of time and make a positive contribution to
the local streetscapes of the city and to the quality of life
of its citizens. In some cases they also serve to protect
underlying deposits of archaeology. Equally importantly, the
retention and reuse of older buildings can engineer benefits
through the reduction in waste generation.
The Built to Last: The Sustainable Reuse of Buildings”
study looks at five existing buildings from an economic, environmental
and cultural perspective, and compares the results of reusing
each building with those estimated on the basis of replacing
it with a new building on the same site. The figures used
for the economic analysis are based on real-life refurbishment
costs.
The study's economic review examines the case-study buildings
and compares the costs for demolition and new construction
with the costs of retaining and re-using the buildings, while
the environmental review analyses the environmental impact
and lifetime cost of each of the five case-study buildings,
detailing the differences and similarities between the existing
buildings and their hypothetical replacements.
Finally, the cultural review establishes the aesthetic, amenity
and heritage values of the existing buildings and compares
these values with the replacement buildings.
Quite a number of issues outside the scope of this study were
identified for further study, including a more comprehensive
study using the methodology on a larger number of buildings,
and a specific analysis of the sustainable reuse of buildings
listed on the Record of Protected Structure. In addition,
further useful studies could include an analysis of the market
end value of reused buildings versus new buildings, and the
effect of urban intensification on the environment; does the
reduction in commuting and urban sprawl caused by intensification
reduce eco points and have a positive effect on the environment?
There is no attempt in this report to deal in detail with
these important issues. It should be noted, however, that
that the actions outlined will be implemented, where feasible,
through the Dublin City Heritage Plan and other partnership
initiatives.
The many organisations and interests which constitute the
Irish construction industry should be made aware that re-using
buildings is a viable alternative to demolition and new construction,
with additional environmental and cultural benefits that translate
to more profitable buildings in the long term.
In the five case studies used to prepare this report, hypothetical
new build scenarios were compared with actual refurbishment
projects in relation to building costs, environmental analysis
and whole life costs. In general, the conclusions illustrate
the advantages, both economic and environmental, of re-using
and extending the lifespan of the building stock.
The studies show that constructing new buildings on brown-field
sites is more expensive than retaining and re-using existing
buildings except in situations where the extent of building
repair and refurbishment required is extremely high. As the
repair costs decrease, the re-use option becomes progressively
more economic to a point where reduced costs of as much as
50% can be achieved. This study has shown that the re-use
of buildings has greater value for the environment and cost
savings over the future life of the buildings. Existing buildings
can also have greater aesthetic and heritage values. The study
findings support the acknowledged international view that
the re-use of buildings can minimise the depletion of non-renewable
resources and is therefore essential to sustainable development.
The results show that a refurbished existing building performs
better in environmental terms than a hypothetical newly constructed
building on the same site. In the buildings assessed for this
report, the environmental impact per m2 is less in the refurbished
building than in the hypothetical redeveloped building. Moreover,
building practice in Ireland will in future need to respond
to European legislation and policy on waste hierarchy, which
will impact on costs and make the re-use of buildings more
attractive.
In most cases, the cost of servicing and running buildings
during their lifetime far exceeds the initial costs of construction.
There should, therefore, be a genuine interest in procuring
built assets with low running and maintenance costs. In four
of the case studies the re-use option generated lower whole
life costs, making this a better environmental option.
In four of the five buildings examined, the re-use option
had lower capital costs. From a cultural perspective the existing
buildings were considered to have added value and thus outperformed
the replacement buildings. It is considered that refurbished
buildings have a particular benefit to offer in commercial
terms. Although figures to support this are not currently
available for Dublin, a study on the rental returns of listed
historic buildings in the United Kingdom has found that they
have consistently outperformed unlisted structures for the
last five years.
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