London Wider Waste Strategy - London - Greater London Authority

Recommendation 47: It is recommended that Government should be lobbied to
impose financial instruments and/or support other measures, such as
demonstration projects and dissemination of best practice, to promote the
treatment and reuse – rather than disposal – of contaminated soils from
demolition and construction sites.
5.44. Discussions with the consultees and a review of available statistics reveals that the
predominant approach by far for treating demolition wastes is by crushing for use on or
off site. It appears that whilst controlled de-construction is promoted as a sustainable
way of bringing down buildings, in as much as it allows for maximum reuse of materials,
deterrents to applying this best practice include:
• the developer’s programme (for example, the date of opening a unit);
• the critical path (for example, civil engineers needing to be on-site during
deconstruction);
• health and safety requirements; and,
• higher costs.
5.45. Conversely, one consultee informed us that de-construction as a technique had been
practised for many years and will continue to be used. Whilst de-construction rather
than demolition is not a new technique, the main influence over which technique to use
is health and safety rather than environmental considerations. De-construction is
usually related to high-rise buildings that cannot be demolished by traditional means
due to nearby residential or commercial premises.
5.46. We were also informed that developers very rarely adopt targets for reuse or recycling of
demolition materials and the main incentive was to get the development built and
operating as soon as possible. When targets were promoted, they were usually set by
public sector clients rather than the private sector. We were informed by one prominent
demolition company in London that whilst the public sector may push for an enhanced
environmental approach, there was a point at which developers would not be willing to
absorb additional costs (if these resulted) despite the environmental benefits. Hence,
there was a point at which economic considerations will take precedence over
environmental issues for developers across all sectors. It is apparent that the private
developer is rarely a driving force for sustainable waste management relating to
demolition and construction and that, whilst public sector contracts may encourage this
to a greater extent, only a relatively small additional price will be accepted before
market conditions apply.
5.47. Discussions with a number of waste contractors also indicated that the main driver for
sustainable waste management practices with regard to demolition and construction was
indeed costs rather than environmental issues. Many felt that they could achieve cost
savings in demolition through the recycling and reuse of hard materials which generated
cost savings over and above the landfill route. Contractors would usually identify such
savings at the tender stage and include them in their tender returns; hence the savings
are passed on to the client and in so doing a contractor that identifies the most
sustainable waste management practices may be more likely to win a project due to cost
reduction. Therefore, it can be seen that the increasing costs of landfill and scarcity of
sites in London is providing a real economic incentive for the recycling of all types of
construction and demolition wastes, including both ‘hard’ and ‘soft’ wastes. This
appears now to be a major stimulus for recycling these wastes, and is likely to continue
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