Abstract
This study is an Investigation into Precast Reinforced Concrete (PRC) Properties and the economic effectiveness of Refurbishing compared with demolishing redeveloping sites.
Table of Contents
1. Introduction.
2. Aims.
3. Objectives.
4. Hypothesis.
5. Research Methodology.
5.1 Methodology
5.1.1 Literature Review
5.1.2 Questionnaires
5.1.3 Case Studies
5.1.4 Methodology Model
5.1.5 Contingences
6. Literature Review
6.1 Defects
6.1.1 Structural
6.1.2 Energy Effiency
Acknowledgments
Throughout this dissertation, many people have provided their personal time and made valuable contributions towards this study. Numerous individuals have assisted me throughout this process, from providing moral support through to aiding the investigation process. I would therefore like to thank the following people.
Mike Frank: As my tutor and dissertation supervisor he has always been available to support and guide me through the process, offering much needed advice and reassurance, he has always been willing to share his expertise and any information which may be benefit to the study.
Tooba Noor: As my tutor and module leader Tooba has been available fro help throughout the dissertation process and has provided invaluable guidance throughout the course.
Barry Slinger: My father, Barry, has been directly involved with the study from the outset, offering an alternative view, providing proof reading, support and willingly giving up his time in doing so.
Housing Professionals:
Participants of questionnaires:
Declaration
I declare the work contained within my dissertation to be my own work and that no part has been plagiarised from any source whatsoever. Where my work and theory or concepts have been taken or adapted from other author’s, these have been properly cited or referenced.
This Dissertation stands at 9,000 words approximately.
Signed;
Print Name:
Date:
List of Figures
1. Figure 1 – Typical PRC Airey Property (Left) and Laing Easiform (Right) 1
2. Figure 2 – Approx. number of some System Built houses and length of time in production 2
3. Figure 3 – Methodological Model 6
List of Tables
1. Table 1 – Contingency Plans 7
2.
1. Introduction.
The purpose of this dissertation is to investigate the economic sense of refurbishing Precast Reinforced Concrete (PRC) properties compared with the alternative of demolishing and redeveloping properties. The information that will be included in this dissertation is the History of PRC properties, common defects, construction processes, repair schemes, cost and the benefits of repair or demolition.
The project proposal is to collect all information for both the negative and positive impacts of Non-Traditional properties, describe their history and how these can be repaired to provide more efficient properties allowing lenders to mortgage these properties to buyers, or demolition of properties and redeveloping.
I will gain information on Non-Traditional House types by researching the facts and figures for” before and after” repair and demolition and redevelopment schemes and conclude if either it has been a positive or negative outcome as well as the feasibility of the scheme.
It was not until after the Second World War those PRC properties were introduced. This was when the replacement and renewal of housing was a big issue, and the use of pre-fabrication for house building in the UK developed in a serious and significant way.
See Examples in Figure 1. Many systems were developed including Timber, Steel, Cast in-situ and Reinforced Concrete (PRC) Properties. Harrison H and Mullin S state’s “Prefabricated reinforced concrete (PRC) houses are non-traditional homes, meaning anything that is not a conventional brick or timber frame structure and includes steel frame, cast in situ concrete and PRC construction.”(2004-Non-traditional Houses)
This was because the government offered incentives to companies who could develop system built properties that could be erected quickly.
Figure 1 – Typical PRC Airey Property (Left) and Laing Easiform (Right).
PRC houses were erected in the UK between 1919 and 1939 non-traditionally. Although the idea for building this type of housing had been around for many years it wasn’t until the 1950s and 60s that it really got some focus.
Many manufacturers produced 1000s of units from widely differing materials and construction forms. The most prolific non-traditional builder George Wimpey, of the pre-cast concrete Wimpey No Fines house fame, produced a reputed 300,000 non-traditionally built units over a 30-year period (Harrison et al, 2004). “When the temporary housing programme got under way, around 50,000 were built each year mostly by local authorities” (Clarke 2005, p.2).
However, the following table attempts to list most of the systems that achieved notable production periods and/or numbers of dwellings built in Figure 2.
Figure 2.Approx number of some System Built houses and length of time in production.
However, Nick Ross states “during 1984 a number of PRC property types were designated defective under the 1984 Housing Defects Legislation” (Ross 2002, p.13) it was no longer possible to secure mortgages against any PRC property.
Essentially this condemned many of the PRC designs as basically defective. Most of the problems related to corrosion of the reinforcement and deterioration of the concrete. After that the lenders would not advance money on them unless they were the subject of an approved repair scheme.
As a consequence of this a significant number of these PRC properties were to be demolished by local authorities or social housing organisations, this was to make way for new developments that were to be introduced instead. Many organisations however retained their PRC properties; this was to find that these properties were refurbished often to improve their thermal performance enhancing a more efficient property. If refurbishment has taken place it is likely that a common repair scheme External Wall Insulation (EWI) was applied, however in some rare cases a scheme to remove parts if not all of the structure and to re-build with a traditional structured wall was carried out.
This dissertation aims to determine which option is the most cost effective way either repair or demolish.
Primary data will be collected through the use of questionnaires with added case studies to allow opinions of professionals in different organisations that have used either option. Secondary data will be the use of authors to identify key points to enhance my selection of question for the primary research.
2. Aims
This dissertation consists of two main aims:
1. To establish the main issues in relation to PRC properties and the option to repair (schemes) or demolition of properties and redevelopment.
2. To evaluate whether refurbishing or demolishing PRC properties provides more efficient and economical sense in doing so.
3. Objectives
The objectives in this dissertation are:
1. To determine why PRC properties require refurbishment or demolition.
2. Identify the reasons for demolition.
3. Identify schemes for refurbishment PRC properties.
4. To establish the negative and positive impacts for Refurbishment vs Demolition PRC properties.
5. To evaluate which is most cost effective.
4. Hypothesis.
PRC properties The Need to Repair or demolish?
5.0 Research Methodology.
Before carrying out research on a desired topic, it is important to consider the different forms of data collection that are available, which is otherwise known as a research strategy, NAOUM (2007, P37) defines this as “the way in which research objectives can be questioned”.
There are two main research types, Qualitative and Quantitative research. It is key that these two types of research are understood before commencing with research as this allows the researcher to select the most appropriate method, and in common cases to use a combination of both.
Quantitative research is a form of research about asking people for their opinions in a structured way so that you can produce hard facts and statistics to guide you. To get reliable statistical results it’s important to survey people in fairly large numbers and to make sure they are a representative sample of your target topic. Quantitative research “seeks to gather factual data, to study relationships between facts and how such facts and relationships accord with theories and the findings of any research executed previously” (FELLOWS and LIU 2008, p, 27).
Qualitative research is research methods such as unstructured interviews, focus groups and participant observation to gain insights and to understand individual’s perceptions. Whilst they do use a set of research methods that are not used in quantitative dissertations, qualitative research is much more than a choice between research methods.” Qualitative research can describe or provide further understanding of a subject and its contextual setting, provide explanation of reasons and associations, evaluate effectiveness and aid the development of theories or strategies.” (RITCHIE J & LEWIS J 2003).
For these two types of research there are various methods of collecting data that is required, and also by doing using primary and secondary research. Primary research is data collected just for this specific topic through the likes of questionnaires, interviews or case studies and secondary research is using existing sources i.e. journals, Books, Internet etc.
In this dissertation the researcher will be using both types of data to ensure a full view of available information will be provided to allow analysing and production of good quality conclusions.
5.1 Methodology.
5.1.1 Literature Review
A literature review was undertaken to ascertain the level of information that is currently available relating to the topic area. “A literature review is a summary of a set of related research papers. It selects information from the papers, and organizes and integrates it into a logical justification for the author’s research. Literature reviews are typically written by researchers who survey previous studies in order to identify research gaps and to place their own work in the context of previous findings” (JAIDKA, et al 2013).
The literature Review in this study will be an analysis of existing literature which will be used in order to answer the key aims of this research, which are to describe the PRC properties and to critically evaluate the differences between refurbishment and demolishment of these properties.
5.1.2 Questionnaires
Questionnaires were conducted by the researcher with selected individuals involved in this area of topic either, tenants giving a response to the positive or negative outcomes before and after refurbishment , as well to local communities were PRC properties are identified or were identified and have been demolished and redeveloped. Also to housing professionals who have been heavily involved with projects where PRC properties have been refurbished or demolished.
These questionnaires were split to get a wide range of data between those provided the schemes or those living in existing PRC areas or redeveloped.
For those two types of applicants involved a number of potential candidates were identified and contacted to ensure they could undertake the questionnaire to allow the researcher gather the required information around the topic area. The reason for this is that it allowed the researcher to select appropriate individuals involved to obtain a greater level of detail that can be created.
5.1.3 Case Studies
5.1.4 Methodological Model
Figure 2 – Methodological Model
5.1.5 Contingences
It was possible that whilst carrying out the research, problems may have occurred that prevented the collection of data or that the amount of data collected was not enough for what was required in order to put together a conclusion for the topic.
Problem Solution/Action
Secondary Sources Unavailable.
Reserve in Library and seek alternatives where possible.
Unable to secure Questionnaire percipients and responses.
Identify a vast number of potential questionnaire candidates as this forms a critical part of the research project. The more that are identified equals a greater chance of response.
Unable to obtain case study information.
Research further organisations to identify where projects have been undertaken and request information to be used in the dissertation.
Table 1 – Contingency Plans
6. Literature Review.
6.1 Defects
As discussed, PRC properties were constructed in considerable numbers post second world war. A combination of factors has subsequently led the identification of problems with PRC properties, from structural issues to poor levels of energy efficiency. The implantation of Decent Homes Standard 2001, which set out to improve social housing in England also had an impact and meant that works to PRC properties would be required (East Cambridgeshire District Council 2012).
6.1.1 Structural
6.1.3 Energy Effiency