January 1, 2001
by Jim Taggart
Over the past decade, through forums such as the recent Maastricht conference and initiatives such as the C-2000 and R-2000 programs, architects and engineers have become more knowledgeable about green design strategies. Organizing plan and section to maximize daylight penetration and natural ventilation, or incorporating technologies such as low emissivity glass and high-efficiency heat pumps, is now common practice in both new buildings and renovations.
At the same time, it is widely recognized that these measures alone will not be sufficient to achieve the desired goal of sustainability in our built environment. External forces such as zoning changes and spiralling land values often conspire to shorten the service life of buildings, even though the building fabric itself may still be in good condition. When one considers the embodied energy in these structures, and the physical implications of materials disposal, these premature losses have a considerable negative impact on the overall environmental equation.
Designing new buildings for flexibility and adaptability will help to address this problem in the future, but there is also a need to change our present attitudes to the demolition and disposal of existing buildings and to extract the full service life from all building materials by reclaiming and re-using them wherever possible. In this way, architects can assume the role of curators, not just creators, of the built environment.
Whereas the challenges in using other green design strategies are largely technical, and their impacts on traditional design practices and contractual arrangements are generally minimal, the same cannot be said when incorporating salvaged materials into new buildings. Architects typically specify materials and products from manufacturers’ catalogues, with few concerns about quality, consistency or availability. In contrast, the uncertainties associated with salvaged materials have been sufficient to limit their use in all but heritage conservation or small residential projects. A new publication from the Greater Vancouver Regional District (GVRD) aims to address this situation in British Columbia, and has much practical and strategic advice to offer architects across the country.
Old to New–Salvaged Materials in New Construction is the result of a study commissioned by Thomas Mueller, Chair of the GVRD’s Demolition and Deconstruction Planning Committee, among whose objectives it is to reduce the volume of solid waste reaching the region’s landfills. The study was undertaken by Paul Kernan, MAIBC, Richard Kadulski, MAIBC and graduate architect Michel Labrie, and it is written and organized to best address the needs and concerns of practitioners.
Old to New draws heavily on the experience gained on three recent Vancouver projects. The C.K. Choi Institute for Asian Research by Matsuzaki Wright Architects, the City of Vancouver Materials Testing Centre by Busby + Associates Architects, and the Liu Centre for the Study of Global Issues by Architectura in collaboration with Arthur Erickson have all successfully incorporated large proportions of salvaged materials. The guide looks at the supply and specification of materials, the effects of salvaged materials on the design process, implications for tendering and contract administration, and the potential for overall cost savings. In addition, the guide identifies the types of salvaged materials and equipment most readily available, and organizes them in accordance with the 16 divisions of the Masterformat. It also lists the main suppliers of salvaged materials in B.C.
For many years, the architectural salvage market has been geared to the needs of heritage preservationists, the individual homeowner or the small builder. More recently, the increased cost and scarcity of large dimension timber has made it worthwhile for salvage contractors to remove heavy timber and glulam members from industrial buildings and retain them for resale. This has generated interest among architects wishing to incorporate reclaimed materials into their projects, and this increased demand has begun to broaden the range of salvaged materials and products available.
While there is an apparent cost benefit to incorporating salvaged materials, these may well be offset by increased architectural fees, higher front end cash flow for the purchase of materials, and a longer period of uncertainty over the final cost of the building. In short, the incorporation of salvaged materials into new buildings needs to be embraced by clients for philosophical rather than purely financial reasons.
The salvaged materials industry is made up of small independent contractors and suppliers who often see themselves in competition with one another. It is prudent to spend some time investigating the situation in your area before embarking on a project of this type. Materials can be obtained either from salvage contractors or suppliers, but the best way to obtain salvaged materials is often to identify and purchase a suitable building already slated for demolition. In the case of the Materials Testing Centre, two suitable buildings already existed on site, and in the case of the Choi Institute and Liu Centre, the client, the University of British Columbia, had redundant buildings nearby. It should be noted that all these buildings were of heavy timber construction, this being, with rare exceptions, the only structural system that readily lends itself to re-use in this way.
An inventory of materials available from an existing building becomes the starting point for schematic design. For both architect and structural engineer, the size and length of the available members will determine the spans and spacing possible in the new structure. Any shortfall in materials will need to be made up from other sources. In the Materials Testing Centre, salvaged heavy timber trusses were re-used in their original configuration, and salvaged glulam purlins were reused on the flat to create a suspended floor. In the Choi Institute, the available trusses were not suited to the small program spaces, so they were dismantled and re-used as elements in a post and beam frame structure. In all cases design flexibility and ingenuity are the keys to successful reuse of materials.
Creating a workable structure for a new building using salvaged materials can be the single biggest challenge for architects. Many other materials and products are straightforward to use, but may be more difficult to source. The case study buildings variously incorporate salvaged sawn lumber, plywood, insulation, specialty metalwork, washroom fixtures and accessories, doors, windows, and even recycled window glass. Procuring all the materials in advance of tender requires money up front and a great deal of research, but enables tender documents to be complete, contractors to view the materials before submitting a bid, and the project to be let as a CCDC-2 Stipulated Price Contract. This was the procedure adopted for both the Choi Institute and the Liu Centre, which achieved approximately 50% recycled content in the completed buildings.
The Materials Testing Centre was also initially set up this way. The schematic design for the project was done based on an inventory of materials from the two adjacent warehouses slated for demolition, but both client and architect wanted to incorporate as many other salvaged materials as possible. Initially, the project was tendered using CCDC-2, with two parallel schedules. The first was to be priced assuming all new materials (except for those supplied by the client), the second assuming substitution of salvaged materials. Bidders responded with only one price, choosing not to assume the risks associated with sourcing and securing salvaged materials. To achieve their goal of 70% recycled content, the architects re-tendered the project as a CCDC-5 Construction Management contract, assigning responsibility for sourcing additional recycled materials to the Construction Manager.
Few, if any, salvaged materials suppliers will guarantee the availability of specific materials or pro
ducts for the duration of the design and tender period. So if pre-purchase is not an option, flexibility must be built into the design. For example, the drawings for the Materials Testing Centre simply identified “cladding,” specifying neither metal nor wood, as suitable material had not been sourced at the time of tender. Similarly, to allow some flexibility in procurement, the architects required all doors on any floor to be the same design and height, but permitted variation between those on different floors. With the City of Vancouver as a client, the lack of a definitive specification for exterior materials at development permit stage was not an issue. Similarly, the applicable building codes permitted the use of salvaged materials where these met the required specification. The situation in other areas may be different, and it is important that the municipality endorse the intent of the project from the outset, and understand the design implications.
Clients should also be aware of the potential for delays if a large number of items need to be procured during the contract period. In Vancouver, as more projects go this route, specialist materials procurement consultants are emerging, and their experience can minimize the risks of disruption or delay. They work from an architect’s or engineer’s “wish list” of materials, sourcing from a range of suppliers and suggesting substitutes where appropriate, based on availability.
Old to New also lays out a case study of a “typical” project, identifying the key decisions that must be made at each stage. A cost comparison concludes that with 50-70% salvaged material content, overall savings of 5-10% on the cost of new construction are possible. Typically, as a percentage of contract value, the labour content is much higher than for a project using new materials. This can provide tangible benefits to the local construction industry.
It is hoped that this guide will encourage architects to incorporate more salvaged materials into their projects, so increasing the overall demand and making it viable to deconstruct, rather than demolish, a greater percentage of our redundant buildings. The case study projects clearly demonstrate that this practice can result in significant benefits to clients, society and the environment, without compromising conventional architectural goals.
Jim Taggart is an Associate of the Architectural Institute of British Columbia. Old to New is available from Thomas Mueller at the Greater Vancouver Regional District Policy and Planning Department. Phone (604) 436 6818, E-mail [email protected]