INTRODUCTION

The construction of new buildings in xxxxxx has dramatically shrunk in the last few years, while the refurbishment of buildings within cities historic centers gained traction, after decades of neglect. This renewed interest was fostered mainly by changes in legislation, municipal investment in public spaces, a general drop in property prices and increased private investment driven by tourism. In 2001, INE (National Statistics Institute) estimated that over 50% of the buildings in xxxx  and xxx  cities were in need of refurbishment in varying degrees. A significant part of these buildings are concentrated on historic quarters and range from the XVIIIth to the beginning of the XXth century. They are built of stone masonry façades and party walls, wood beam slabs, wood trusses and wood frame partition walls. Both the stone and wood partition walls were gypsum plastered, while often the main façade would be covered with ceramic tiles. In refurbishment interventions, interior layout reorganization is the main focus. Façades, wood slabs and roofs are either repaired or kept in original condition.

The increased demand of refurbished buildings is frequently being met with modern construction techniques and materials, often ill adapted to the problem at hand. This happens both because modern wood frame partition wall construction is not competitive and traditional techniques have either become too expensive or craftsmen are no longer available. A definite need exist for approaches that better integrate the specific requirements of refurbishment projects with mass production. Nonetheless, building refurbishment design and construction are piecemeal and chirurgical by nature and as such not prone to standardized construction methods.

Developments in computational design methods and their integration with digital fabrication processes allow us to think of a customized construction paradigm (Naboni & Paoletti 2015). This new process strategy is especially suited to the refurbishment of buildings built with traditional construction techniques, a diversified corpus in which the interventions are chirurgical and non-standard. Insulation Cork Board (ICB) is a natural and renewable material which maintains all of the characteristics of raw cork: lightness, buoyancy, viscoelasticity, low heat and sound conductivity and acts as a fire retardant (Gil 1998, Fortes et al 2003, Pereira 2007). Moreover, as a result of its production process which outputs a big block, it’s better suited to architectural applications and as Sousa (2010) work demonstrates, apt for customization processes with CNC technologies. We foresee that a file-to-factory digital process  will have several advantages in this context: higher quality and speed without sacrificing scope or increasing cost (Kieran & Timberlake 2003).

METHODOLOGY

A subdivision grammar, that follows up on Sass’s Wood Frame Grammar(2005)(WFG), will be used as a starting point to troubleshoot the nature of corner conditions, wall ends and infill walls. In this grammar a few more cases are needed to solve the possible geometric configurations of interior walls, and more importantly the nature of the interface between the wall and the support, be it wooden beam slab, stone wall or ceiling. The next step will be to define the material system components, their geometry, constructive and structural functions and the assembly and fabrication processes. ICB, plasterboard, plywood and OSB will be the basic materials with which the candidate systems will be defined. Three different systems will be considered: wood frame – cork infill panels; sandwich panels with cork infill and plasterboard/OSB sheet layers (Sass e Griffith (2006); sandwich honeycomb cork infill panels with plasterboard/OSB sheet layers. The material system will be selected for its freestanding structural properties, cost, capacity to allow room for infrastructure in its core, ease of assembly and lightness. The systems will be parametrically modeled and tested and evolved using computer aided physical simulations. Digitally fabricated prototypes will be used to test joints and assembly processes. Six buildings were selected as case studies for analysis of the common needs and characteristics of these interventions and testing of hypothetical material systems.

RESULTS

The ultimate goal of this work is to develop a parametric cork partition wall system and a customizable digital design and fabrication process for building refurbishment. The parametric partition wall must address the need of a process to integrate infrastructural and constructive systems in design, fabrication and assembly. It must also be a more symbiotic and sustainable solution to refurbishment than current methods, improving also on the ease and quickness of assembly process. Lastly, it should be a cheaper alternative.

DISCUSSION

This work hopes to demonstrate the relevance and flexibility of digital design and fabrication in the context of building refurbishment, and thus contribute to an improvement in refurbishment practices. It also aims to integrate infrastructural systems, acoustic and thermal performance considerations in generative processes of partition walls.