Sustainability: spotlight on construction
Last month, IEM presented an ongoing project to relocate the Princess Margaret Hospital in Swindon according to the sustainability principles of The Natural Step. Since walls, floors and ceilings are integral to all buildings, they provide three obvious places to explore how more sustainable decisions were put into effect. By Jas Dhami, a building economist with Carillion Building, and Dr Mark Everard, The Natural Step.
The design phase identified double-skin plasterboard walls as a suitable solution ensuring flexibility. Instead of the more traditional approach of buying according to the market, Carillion took the step of specifying the optimal sizes of board required to complete the job that will minimise contractor time on-site to complete installation and also minimise waste production.
To initiate this, the Carillion Building Economist visited various interested manufacturers to discuss sustainability challenges. The successful supplier, LaFarge, developed a new product to make further progress with the Sustainability Action Plan (SAP). This product was a single board, comprising just one 15mm skin instead of the twin 12mm panels in the original design.
Furthermore, the board innovated by LaFarge was designed to withstand substantial wear and tear, enabling savings, and was also pre-finished, eliminating the need for skimming with plaster and the number of coats of paint required. Prior to involvement at the Princess Margaret Hospital (PMH), LaFarge did not commonly practice the take-back of off-cuts, but immediately agreed so to do by backloading vehicles delivering to Swindon and other local sites.
The benefits from this range of innovations were considerable, including reducing the requirement for labour-intensive 'wet trades' on-site, and reducing material inputs to product and installation. Raw material inputs into the board itself were decreased by almost a half, and the boards themselves are recyclable at the end of their useful life. The economic savings included an immediate £200,000 by going to a single board system, and an additional £85,000 by reducing the planned three-coat paint system to a two-coat system.
To maximise flexibility and replication, suspended ceilings were identified in the design phase. For hospitals in the UK, Health Technical Memoranda (HTM) 60 specifies the type of tiles and the functional properties that are required for different areas. The design specified recycled mineral fibre ceiling tiles, and that these in turn should be recyclable at end-of-life, or if landfilled, must be inert.
The design also identified a standard tile size set in steel and aluminium, both fully recyclable, throughout the entire hospital. This eliminates off-cuts and wastage, and also reduces time on site for contractors, as well as maintenance and cleaning requirements throughout life.
Part of the initial design, but also a spur to partnership and innovation, each contractor was asked to quote for just two tiles from their ranges that met cost budgets and possibly all six of the HTM requirements. In order to continue to challenge the trade contractors to make further progress with effective sustainable development, Carillion ran workshops on the The Natural Step (TNS) Framework for manufacturers and installers once they had been awarded contracts, requiring that they developed their own sustainable development targets based on the TNS Framework and consistent with achievement of the SAP.
Implicit in the design of flooring systems was a requirement for the most environmentally friendly materials, whether derived from sustainably-managed resources, or reusable at end-of-life to avoid accumulation of pollutants. However, it was soon realised this would be a lot more tricky, addressing issues such as those raised in A Material Dilemma (IEM, May 2001), and required a close evaluation of four materials - linoleum (lino), rubber, PVC and non-chlorine vinyl.
The basic constituents of lino are linseed oil, cork, limestone and jute, combined by an energy-intensive manufacturing process. There are sustainability benefits to be gained from the long life of lino, as indeed for rubber and vinyl flooring. Furthermore, trials suggested that the 'organic' feel of lino underfoot was attractive, and lino also feels warmer and has more sound-absorbent properties in the formulations tested. On the down-side, for most resilient flooring applications across the hospital, a thicker layer of lino would be required as compared to rubber and vinyl, increasing the volume of product needed. At end-of life, lino is biodegradeable, but not easy to recycle.
Rubber flooring is also a long-life product (20 years) and is derived from a potentially sustainable source (trees). Furthermore, it can be recycled for use in cars, although the same practical problems of removal and contamination apply. The 'feel' and sound absorption of rubber flooring was also found in tests to be superior to lino.
By contrast, the 'non-green' credentials of PVC are well-known. However, recent work conducted by The Natural Step - as reported previously in IEM (PVC: Stepping Up the Sustainable Development Agenda, September 2000) - identifies key challenges for the delivery of a fully sustainable life cycle for PVC, with which the European industry is now grappling. However, for the time being, Carillion have decided that the infrastructure for sustainable decommissioning of PVC in the UK is lacking, and that although in the words of the SAP, "The jury is still out on how much better its alternatives are for the environment ", the presumption for now is against PVC.
Carillion also explored a chlorine-free vinyl. However, this line of products is still in the development phase so it was not used at Swindon, though it may be reevaluated for future projects.
The experience at Swindon endorses the views expressing in A Material Dilemma that material choice with sustainable development in mind is a tricky issue in practice, lacking a straightforward solutions and requiring detailed thought about a range of issues quite apart from the material itself.
Not all of the design details have been planned in detail, leaving scope for development of sustainability thinking through partnership and innovation by prospective suppliers. For example, Carillion is considering exploiting solvent-free adhesives and taping materials for skirting, further reducing chemical and energy inputs, and enhancing working environments. Carillion wants to stimulate sustainable innovation with suppliers and ensure they benefit from their contribution to the SAP.
A enormous number of lessons were learnt from Carillion's experience at Swindon. Perhaps the most important is that sustainable development is not about doing additional things, but about doing things in new ways. As long as organisations perpetuate the mistaken notion that sustainable development is an additional, perhaps even retrospective, consideration, then barriers will remain. True commitment to sustainable development is recognition that it is about being better prepared for the inevitable changes that will be enforced by a fast-changing world, and, it is about pre-empting both opportunities and obstacles.
For Carillion, the penny certainly dropped that sustainable development presented both major opportunities as well as scope for market differentiation. Lessons learnt from the PMH Relocation Project will spread across the Carillion Group to other projects and business activities. Leaders on the client side of the construction industry, as well as in other sectors of business, should take note, as must those in government who are tasked with shaping building regulations and other relevant policies.
Carillion's PHM Relocation Project also demonstrates the benefits of partnership. In an unsustainable world, true sustainable development is not yet as simple as it should be. Material choice is an innovative process involving detailed consideration of the whole life cycle, and, by developing partnerships with the supply chain to stimulate and reward innovation, Carillion has made impressive progress with promoting ownership of the mission of creating a sustainable hospital, through encouraging a common understanding of sustainability with all partners in the project. This depth of team-building was a ground-breaking step on Carillion's part, and one that has paid back substantially in terms of learning and innovation.
Another important lesson is that 'sustainable' does not equal 'more expensive'.
Experience at Swindon has revealed, through many novel initiatives that are
ecologically and socially beneficial, no negative effect on economic considerations.
In addition, some even improved the financial performance of the project with
longer term, holistic benefits.