The International Conference “Building Sustainability Assessment 2012 (BSA 2012)” is co-organized by the Greenlines Institute for Sustainable Development and the School of Engineering of the University of Minho and will be held in Porto, Portugal, from 23^rd to 25^th of May 2012.

This is the first of a series of conferences on the field of Building Sustainability Assessment and LCA tools and methods.  The event is supported by high prestige partners, such as the International Initiative for a Sustainable Built Environment (iiSBE), Portuguese Chapter of iiSBE (iiSBE Portugal), Sustainable Building Laboratory (SB-Lab), International Journal on International Construction (IJSC), Ordem dos Arquitectos (OA – Portuguese Architects Professional Association) and Ordem dos Engenheiros (OE – Portuguese Engineers Professional Association).

Building sustainability involves various relations between built, natural and social systems and therefore comprises a complex of different priorities that require consideration at each stage of a building’s life-cycle. To cope with this complexity and to support sustainability, systematic, holistic and practical approaches to building design need to be developed. These approaches are aimed to support the development of a building design that achieves the most appropriate balance between the different sustainability dimensions and can be used with two different objectives: to support the sustainable building design; and to assess and recognize the efforts of the design teams in developing high-performance buildings. Building sustainability assessment methods and tools can be used since the very beginning of the design stage in order to gather and report information for decision-making during the different life-cycle stage of a building.

During the last two decades a significant number of environmental and sustainability assessment tools for buildings have been developed. The main goal, at present, is to develop and implement a systematic methodology to support a building design which achieves the most appropriate balance between the different sustainability dimensions, and which is, at the same time, practical, transparent and flexible enough to be easily adapted to different kinds of buildings and to the constant evolution of technology. BSA tools and methods are constantly evolving in order to overcome their various limitations, but they continue to be based in a different list of indicators, which cause difficulties in comparing results from different systems. In order to overcome these constraints, both the International Organization for Standardization (ISO) and the European Committee for Standardization (CEN) have worked actively in the last few years to define standard requirements for the environmental and sustainability assessments of buildings. On the other hand, Energy Certification of buildings is now considered in some countries too limited to embrace the consequences of the built environment on the natural, social and economy systems and therefore a broader list of indicators is being integrated in the certification processes of the building performance. This is challenging a common international understanding in the field.

Based in the abovementioned context, BSA 2012 is the 1^st international conference focused in emerging challenges in the field of building sustainability assessment. With the organization of this event, we expect to create the adequate conditions to promote higher international cooperation on the field; share of knowledge; presentation of successful case studies; in order that it is possible to formulate proposals that include new principles and initiatives for the development of more consensual approaches for Building Sustainability Assessment and Life-cycle Analysis (LCA) of the construction sector. In our opinion this consensual approaches will contribute to a better understanding about the sustainable construction concept and will boost an effectively higher compatibility between the natural and artificial environments.

The last day of the conference is dedicated to Workshops. The Organizing Committee is convening these Workshops to facilitate and promote the practical implementation of BSA and LCA tools and methods in the construction sector to support decision-making for developing Sustainable Construction at international level. During this day, the most important international and national BSA and LCA tools and methods will be presented.  Our special thanks to all workshop coordinators and to the companies involved. Without their contribution it was not possible to organize such interesting programme.

The subjects discussed in this conference cover a wide range of important issues related with Building Sustainability Assessment and LCA methods and tools. We would like to thank to all authors, the high standard contributions that we have received for this conference. This Book of Proceedings contains about 100 papers that reflect a profound work and critical research that will give an important contribution towards sustainable development. This book is organized in the following topics:

- Chapter 1: Emerging tools and methods for building sustainability assessment (BSA);

- Chapter 2: Development and application of existing BSA tools, methods and certification systems;

- Chapter 3: Comparison of BSA tools and methods;

- Chapter 4: Normalisation of life-cycle analysis and building sustainability assessments;

- Chapter 5: Environmental life-cycle analysis (LCA) of materials, products and buildings;

- Chapter 6: Life-cycle costs analysis (LCCA) of materials, products and buildings;

- Chapter 7: Education on building sustainability assessment;

- Chapter 8: The relevance of the BSA methods for the environmental policies;

- Chapter 9: Integration of BSA tools in Building Information Modelling (BIM).

The Organizers would like also to thank to the Scientific Committee, whose efforts and hard work secured the high quality of all contributions to be published in this conference. A special gratitude is also addressed to our sponsor SIKA Portugal and to the Municipality of Porto.