intervention strategies for renovation of social housing estates

Theoretical background Chapter 2
---------------------------------------------------------------------------------------------------------------------
back to its original state (Flourentzou, 2002) in Alanne, 2003). According to PRC
(Bouwcentrum International the Netherlands) 5 refurbishment is a “comprehensive renovation
work (repair of all defects) of (high-rise) residential buildings”. Restructuring is one step
further refurbishment, at least in terms of scale. It covers “all activities aimed at the
improvement of the living and working conditions in (high-rise) neighborhoods and districts,
including new building, demolition and infrastructural works”. According to Ouwehand and
van Daalen (2002) renewal is a radical approach at neighbourhood level where dwellings are
made available for middle and higher income households.
The definition of renovation provided by Thomsen refers to renovation as an extension of
building life-cycle in terms of physical, functional, financial, architectural and ecological
aspects. Therefore, a study of the life-cycle, should concentrate not only on their physical
performance but also on their functional and (micro) economical performance as underlying
factors about continued use, transformation or destruction (Gruis at al, 2006).
According to the model of “sharing layers of change” developed by the American architect
Stewart Brand, who is specialized in recycling building, (Brand, 1994 in de Jonge, 2005 and
Leupen, 2006), the building can be stratified into six layers. Each has its own life-cycle and,
consequently, a specific length of useful life. The layers are the following: site (earthworks),
structure (load-bearing elements), skin (covering and projecting membrane), services
(heart), space plan and stuff. Leupen added another category that is the access system
(stairs, corridors, galleries and lifts), such as are found in large residential buildings. The life
span of the building structure that includes, for example, foundation and bearing elements,
ranges from 30 to 300 years. The skin, that comprises all the elements of the exteriors, can
be 20 years (even if motives related to fashion, technology and energy might influence the
span). Space plan and the interiors can (exceptionally) reach 30 years (de Jonge, 2005).
Life cycle of building elements can be clustered as follows: long-cycle more than 25 years
(bearing structure); intermediate life-cycle between 15-25 years (installations, inbuilt,
gutters/flats roof and envelope) and short life-cycle (finishes, interior decoration ICT and
demotic) less than 15 years (de Jonge, 2005). Therefore, a renovation approach based, for
example, on the entire substation of existing building envelope could extend life-cycle up to
25 years.
However, to appraise the best solution a diagnosis has to be formulated for each case
(Priemus, 2005). Such an action might lay in the building pathology that studies the causes
of decay and collapse of buildings and building components (Gruis at al, 2006). Such initial
investigation could be particularly true for envelope directed renovation that requires, for
example, a diagnosis of the structural capacity of the block as a starting point for assessing
potentials of transformation – the therapy.
Diagnosis on the structural capacity of the block for envelope renovation has to be focused
on the long-cycle elements, the bearing system, what in Dutch is called the “casco” structure
(Leupen, 2006).
CONCLUSIONS
From the four sections presented in this chapter, five main considerations can be made.
- Deprived European large housing estates built after World War II have common
problems: the quality of the stock, asset management and residents. The urban layout,
the number of people living there and their function on the housing market are relevant
problems as well.
- Despite theories and models developed by researchers to explain the process of change
and decay of neighbourhoods, it has not been clarified jet how and where the process
starts (Priemus, 2005). The Model of Housing Decline by Prak and Priemus (1984; 1986),
is still valid and considered the most-all embracing (van Beckhoven et. El., 2005).
5 PRC Bouwcentrum International The Netherlands (2005) Sustainable Refurbishment of High-Rise Residential Buildings
and Restructuring of Surrounding Areas, report for European housing ministers’ conference held in Prague, Czech
republic,14 - 15 march 2005
8. B