Integrated project delivery methods for energy renovation of social housing
Authors: T. B. S. Rahola
Year: 2015

Optimised project delivery methods forsocial housing energy renovations


European Social Housing Organisations (SHOs) are currently facing challenging times. The ageing of their housing stock and the economic crisis, which has affected both their finances and the finances of their tenants, are testing their capacity to stick to their aim of providing decent and affordable housing. Housing renovation projects offer the possibility of upgrading the health and comfort levels of their old housing stock to current standards and improve energy efficiency, and this solution also addresses the fuel poverty problems suffered by some tenants. Unfortunately, the limited financial capacity of SHOs is hampering the scale of housing renovation projects and the energy savings achieved. 


At the same time, the renovation of the existing housing stock is seen as one of the most promising alternative routes to achieving the ambitious CO2 emissions reduction targets set by European authorities – namely, to reduce EU CO2 emissions to 20% below their 1990 levels by 2020. The synergy between European targets and the aims of SHOs has been addressed by the energy policies of the member states, which focus on the potential energy savings achievable by renovating social housing. In fact, the European initiatives have prioritised energy savings in social housing renovations to such an extent that these are referred to as ‘energy renovations’. Energy renovation is therefore a renovation project with higher energy savings target than a regular renovation project.


In total, European SHOs own 21.5 million dwellings representing around 9.4% of the total housing stock. Each SHO owns a large number of dwellings, which means there are fewer people to convince of the need to make energy savings through building renovations, maximising the potentially high impact of decisions. Moreover, SHOs are responsible for maintaining and upgrading their properties in order to continue renting them. As such, SHOs are used to dealing with renovations on a professional basis. The limited financial capacity of SHOs to realise energy renovations magnifies the importance of improving process performance in order to get the best possible outcomes. In the last 30 years numerous authors have addressed the need to improve the performance of traditional construction processes via alternative project delivery methods. However, very little is known about the specifics of renovations processes for social housing, the feasibility of applying innovative construction management methods and the consequences for the process, for the role of all the actors involved and for the results of the projects.


The aim of this study is to provide an insight into the project delivery methods available for SHOs when they are undertaking energy renovation projects and to evaluate how these methods could facilitate the achievement of a higher process performance. The main research question is:


How can Social Housing Organisations improve the performance of energy renovation processes using more integrated project delivery methods?


The idea of a PhD thesis about social housing renovation processes originated from the participation of TU Delft as research partner in the Intelligent Energy Europe project SHELTER1 which was carried out between 2010 and 2013. The aim of the SHELTER project was to promote and facilitate the use of new models of cooperation, inspired by integrated design, for the energy renovation of social housing. The SHELTER project was a joint effort between six social housing organisations (Arte Genova, Italy; Black Country Housing Group, United Kingdom; Bulgarian Housing Association, Bulgaria; Dynacité, France; Logirep, France and Société Wallonne du Logement, Belgium), three European professional federations based in Brussels (Architects Council of Europe, Cecodhas Housing Europe and European Builders Confederation) and one research partner (Delft University of Technology).


Research methods


This thesis is composed of five studies. The first study is based on a literature review. The second study is based on five case studies from four countries (Belgium, Italy, France and United Kingdom), a questionnaire completed by 36 SHOs from eight countries and 14 interviews with experts from ten countries. The third is based on two French case studies and the fourth and fifth are based on 8 and 13 Dutch case studies respectively.


Construction projects in housing involve a high number of professionals and take place over a long period of time. External factors, such as the economic and political situation or changes in construction or procurement regulations, can have a considerable influence on the construction process. Moreover, the specific characteristics of the construction sector of every country can also shape the process. In consequence, there are many interrelated variables that can have an influence on the dynamics of the process and on the outputs achieved. Research that seeks to understand the causes of changes in this process need to dig deeper into the internal and external characteristics of the process, which makes case study research the most appropriate research method for this type of study.


The cases in each of the studies have been selected because innovative project management methods aiming for better collaboration between the participating actors were applied and because it was possible to gather high-quality data concerning these projects. The data were gathered mainly through interviews but other methods were also used: a questionnaire, observations and an analysis of tender documents. A protocol based on the recommendations of case study research literature was applied to assure the scientific validity of the data collected through the interviews. The case studies were complemented with a wide-ranging literature review covering scientific publications on project management in construction, mainly from the UK, the US, Australia, the Netherlands, Hong Kong and Finland. Reports from Intelligent Energy Europe projects were also reviewed, as well as legal texts relating to the tender options open to European social housing organisations.


Construction management methods


How to improve the performance of construction processes has long been and is still one of the key issues of the construction industry sector, social housing included. The performance of construction processes has been addressed from a range of perspectives in the construction management literature and diverse project management methods have been proposed. These methods are interrelated and in constant evolution. Moreover, different terminology is used to describe similar methods, which makes it difficult to obtain a clear picture. To simplify, three main perspectives or methods to improve the process integration and actors collaboration can be identified:


• the multi-project: supply chain integration;

• the single-project: integrated project delivery methods;

• and collaboration: partnering.



Supply chain integration looks at the performance of the construction process from a multi-project perspective, relating the construction process to an industrial process. The project delivery method takes a single-project perspective into account because it is based on the premise that the complexity and singularity of any construction project will make it unique. Finally, partnering is focused on the characteristics of collaboration between the actors involved in the construction process.


The singularity of renovation projects and the limitations of public procurement make the single project perspective the most feasible strategy for improving the process performance of social housing renovation projects. As such, the analysis of the project delivery methods is the most suitable method for improving the performance of renovation processes. The literature review shows that the more integrated project delivery methods are particularly indicated for construction projects with a high commitment to sustainability in general and for energy performance in particular. The literature review also reveals that the key factor in the process efficiency of all project delivery methods is collaboration between the actors involved in the project.


Partnering methods can have a substantial positive influence on process performance. The study of the legal limitations imposed by the currently applicable public procurement Directive 2004/18/EC shows that even though a limited amount of tender options are available, is it possible to tender projects that apply integrated project delivery methods using the competitive dialogue procedure. Moreover, the recently approved but not yet enacted public procurement Directive 2014/24/ EU facilitates even further the use of competitive dialogue tenders for social housing energy renovations.


Project delivery methods in European social housing energy renovations


This study is based on five case studies, 36 questionnaires and 14 expert interviews, and identified four main project delivery methods for the energy renovation of social housing, namely:


• Step-by-Step (SBS)

• Design-Bid-Build (DBB)

• Design-Build (DB)

• Design-Build-Maintain (DBM).



SBS can be considered a major renovation when the replacement of a series of building components eventually produces the same final result as a renovation project. In order to optimise the service lives of building components, an SHO might choose to split a major renovation project into a series of minor renovations. Cost-efficiency is achieved by procuring a large number of replacements only when a particular component has reached the end of its service life. This project delivery method will not usually include a design phase because these interventions usually involve replacing building products and systems. DBB, DB and DBM take place all at once and involve design companies, construction companies and main