BRE IP9/06 PDF

Introduction

Over half the expenditure in the UK construction industry relates to the repair, refurbishment and maintenance of existing buildings, though much current practice and advice are primarily aimed at new build and modern building fabrics. With the growing emphasis on re-use and regeneration of the built heritage there is a need to evaluate the costs and benefits related to modern building practice against the occupancy and use of Victorian and Edwardian housing in the light of requirements for materials, durability and whole building performance.

More than 4 million houses in the UK date from before 1919, so continued use, reuse, and restoration of these houses represent unique opportunities and associated risks.

The potential conflicts between requirements for modern houses and the performance of older houses have been highlighted in a number of high profile projects. An example is the redevelopment in Nelson, Lancashire (Figure 1) where the local authority's decision to demolish more than 400 19th century houses in the Whitefield area was successfully challenged. A second example occurred in 2005 when conservation groups raised concerns at the large scale demolition plans of the then Office of the Deputy Prime Minister, which seemed to indicate a lack of joined up thinking on sustainability and sustainable communities. These concerns were further highlighted by the publication in 2005 of the 40% House report (Environmental Change Institute, 2005) which advocated the demolition of up to 8 million houses, including a very large proportion of those constructed before 1919. These figures need to be seen in the context that more than 80,000 dwellings per annum were demolished under slum clearance powers in the early 1970s, but this fell to some 4200 in 1992, an annual replacement rate of less than one in every 4750 dwellings.

The situation is clearly complex, with competing demands, and so it is essential to evaluate the various options and determine a way forward that produces the overall lowest environmental impact in that particular time and place. To be sustainable these need to be evaluated and considered alongside the whole life cost for each option, and the societal impacts and benefits of any proposed redevelopment, whether as new build or refurbishment.

The project summarised in this Information Paper builds on the work reported in BRE Information Paper IP9/02 on sustainable refurbishment (Anderson and Mills, 2002) which was developed as a methodology and tool (Office Scorer) for assessing the choice between refurbishing and redeveloping office buildings, and which concluded that, typically, refurbishment is lower in both environmental and whole life cost impacts than redevelopment. BREEAM EcoHomes XB (the environmental rating for existing housing) is an environmental assessment tool launched in June 2006 by BRE which can be applied to the refurbishment of domestic housing, and which enables decision making to take account of a wide range of key issues relating to the built environment.

The project aimed to formulate a method of assessing Victorian house refurbishment similar to that used in BREEAM EcoHomes 2005. This was seen as realistic because of the comparatively small number of typologies that housing of this era fits into – brick or stone-built terraced housing on two, three or four levels. The objectives of the project were to:

● evaluate the refurbishment/conversion of traditionally built housing dating from 1840–1919, looking specifically at competing requirements for modern energy and acoustic standards, whole building performance and the effects of durability, reliability and maintainability of the building fabric

● examine the economic, environmental and social costs and benefits of retaining this part of the building stock

● develop a methodology that can be used in the assessment process.