Terry Quarmby argues that new building products need to be designed with deconstruction in mind
The UK government - often following rules from the European commission - has attempted to address the problems associated with waste by applying a number of protocols and policies backed up by legislation.
Certainly in sectors involving construction, packaging, automotive, electronic and electrical equipment, chemicals and hazardous substances the relevant regulations are prescriptive and, in general, regularly reviewed to account for changes in socioeconomic circumstances. However, there remain questions as to whether these reviews focus on the long-term implications of waste management, in particular the disposal routes for waste in the future, and whether they are as detailed and forward-looking as they should be.
The cost of doing business
The landfill tax was introduced in October 1996 to help the UK meet its obligations under the EU Landfill Directive (99/31/EC). An accelerator has applied to the tax since 1999, making it increasingly expensive to send waste to landfill and encourage producers to opt for cheaper disposal options. Sending waste to landfill in the UK is set to rise to £80 a tonne in April and remain at least at that level until 2020.
There has been steady decline in the use of landfill, with many sites closing and few new ones opening. What will eventually replace landfill is not clear, however. One thing is certain: waste production is not on the decline now nor is it likely to be soon. While we deride the use of landfill as a wholesale answer to waste disposal and bemoan energy-from-waste plants and incineration as costly to the environment and the pocket, there remains no other viable alternative to dealing with waste.
If we look at the construction industry, about 100 million tonnes of construction, demolition and excavation waste (CDEW) are produced each year in the UK, with only 40% recycled. The remaining 60% is either landfilled or used as engineering backfill in landfill sites. These figures may be improving slightly because the demolition industry tends to use waste transfer stations (WTSs) as a means to reduce landfill costs and avoid the tax. But with many WTSs charging around £100 a tonne plus haulage they are not necessarily a cheap alternative.
Some construction companies are doing more to separate waste onsite, so increasing amounts are being directed away from landfill, but plenty of improvements can still be made. One of these would be to eliminate, or at least reduce, the waste generated by construction products, but this is a subject that has so far managed to avoid proper debate.
Material selection
The demolition industry has a good record on salvaging and recycling construction products, but that success is at risk as improvements to energy and carbon reduction in new products produce poor-quality recyclate and nonexistent salvage values. For example, some end-of-life products would have started out as soft and hard furnishings containing foams and even polystyrene fillers set into chipboard, MDF or laminated ply board. Many structural timber components, meanwhile, are laminated or glued to inseparable layers of other materials. Even traditional-looking masonry, brick or concrete elements are often imitations or filled with expanded foams or high-tensile steel wires that are impossible to separate.
It would seem that, in the drive to improve energy efficiency and reduce carbon emissions in new construction projects, there has been a failure to deal with the consequences.
Although the amount of such waste may be small compared with the 100 million tonnes produced annually by the building industry, it is important to remember that the "C" in CDEW is "construction waste", which is predominantly made up of manufactured products that are used in buildings and construction projects. These products are designed with a lifecycle of 25-30 years, so will be a long-term problem unless action is taken soon.
The real sting in the tail is that these products are also a problem now. Often there is more clean timber for disposal than is needed and biomass power stations have become swamped. Global demand for chipped timber to make boards, meanwhile, fluctuates at such alarming rates that project planning and time frames often suffer. Although WTSs can handle the CDEW currently directed away from landfill, they would be overrun if they had to deal with a further 60 million tonnes. And, WTSs still use landfill sites to dispose of hard-to-recycle materials.
Salvage of reusable materials is fast becoming a thing of the past because the products of today are designed to be cost-, energy- and carbon-efficient during their lifecycle rather than at the end of it. There is an obvious conundrum here: we desire to preserve natural materials by substituting them for manmade ones, but this often leads to the creation of products whose materials cannot be reclaimed or reused, casing more waste. Designers of construction products, structures and infrastructure need to reduce waste at source to cut costs and promote the use of sustainable materials that can be reclaimed or recycled.
Building a solution
For a number of years there has been a debate over "design for deconstruction", whereby the materials used in the built environment can be reclaimed for use again. Unsurprisingly, it hasn't received the attention it warrants, which may be attributed to a number of issues, not least aesthetics, cost and lack of government support. But this is not an isolated problem concerned only with the products of construction, it is one that affects all industries and their waste now and in the future.
Outside incineration, there appears to be no viable alternative to landfill that is capable of accepting and dealing with the volumes of waste generated today and the foreseeable future. With the bulk of waste expected to be directed away from landfill within the next six years, this is an unacceptable position for the UK's industrial and commercial sectors and it is time that government initiated and instigated the solutions.
So what are the solutions? There are no quick fixes, which makes it more important to start the process of repair or restoration as soon as is practicable. The demolition industry wants design for deconstruction to play a major part in this process because it offers a simple and uncomplicated route to identify: reclamation and recycling opportunities; safe systems of deconstruction; and preformed environmental impact assessments for product placement and disposal.
Coupled with the drive for "building information modelling" (BIM), design for deconstruction could be integrated into building and construction schemes where the products and elements of the new build can be evaluated for energy and carbon efficiency throughout their life and at the end of that cycle. In that way, the environmental impact of a product can be efficiently assessed before use and its disposal costs, and/or value, determined long before it reaches the end of its useful life in a building.
Both BIM and design for deconstruction can be drivers that assist and influence product and building designers to develop better quality and longer lasting materials. While neither of these concepts may be the definitive answer to the problem of waste management, either would go a long way towards creating a solution.
