End of life
Land Design Planning Contracting Construction Refurb
There are costs and benefits to each consideration and this section will provide some information to support decision-making around end of life issues. End of life considerations are closely related to other stages of the value chain, in particular design and construction. End of life, also referred to as deconstruction and demolition, is the stage when building materials are dismantled, reused, recycled, recovered or disposed of, which can have significant environmental and economic impacts.
Consider that buildings are responsible for 1/3 of landfill waste in the UK with a landfill tax increasing to a rate of £3 per tonne to £32 per tonne for disposals of active waste and increasing from £2 per tonne to £2.50 per for inactive waste from 1 April 2008. Also consider UK buildings use 13% of raw materials resources, with an aggregates levy increasing from £1.60 per tonne to £1.95 per tonne for those commercially exploiting taxable aggregate in the UK, effective from 1 April 2008. This is the first rise since its introduction.
Demolition is an important component of sustainability in the whole life cycle of construction; however, it is often overlooked when mapping inter-relations in the construction process to the effect of great costs. Understanding the opportunities to reduce, reuse, and recycle and embedding these in construction activities makes good business sense. If long lasting materials have been utilised in the first instance then re-using them becomes more viable.
InterfaceFLOR’s initiative, “Closing the Loop”, is to redesign processes and products to increase the use of recovered, recycled and renewable materials in the manufacture of new, high quality and durable products.
- How can deconstruction be planned for?
- How can demolition materials be reused or recycled?
- What pollution issues should I consider?
1. How can deconstruction be planned for?
Deconstruction is linked to the Design stage of the construction value chain in the following ways.
- Design of buildings affects the feasibility and energy required to separate materials for recycling and disposal.
- Designing for accessibility to material components requires strategic planning so that a material which may be reused can be accessed without needless demolition of other materials around it.
- Modern building methods often rely on composite forms of construction such as steel/concrete and steel/timber. Such composite forms are very difficult to separate at end of life and thought should be given to their design and applicability for a given building.
The Building Research Establishment Environmental Assessment Method (BREEAM) Green Guide to Specification provides useful information on specification for refurbishment and end of life.
Demolition of materials carries inherent costs and benefits, which, if embedded into the material contracting stage of construction, can secure cost reductions. The Institute of Civil Engineers (ICE) Demolition Protocol and Aggregain Demolition Module provide methodologies for auditing, managing and accounting for environmental and economic benefits at end of life. These include considerations for good practice resource recovery and demolition.
- Site investigations, e.g. Contamination assessment; Sub-surface structures; Tunnels; Vibration impacts; and Stressors of dust and noise impacts from demolition.
- Construction drawing overview to check for possible affects on demolition e.g. pre-stressing.
- Results of level 3 asbestos surveys on demolition.
- Targeting local needs for materials reuse (demand).
- Materials condition survey.
- Site restraints.
- Safety risks from resource removal e.g. removal of external balcony rails exposes safety risks for both executing the removal and leaving an open edge on the building.
2. How can demolition materials be reused or recycled?
Once an assessment and activities are undertaken to secure materials from demolition, their reuse is influenced by the following aspects.
- Its actual component post-demolition – e.g. ensuring materials are not contaminated.
- The waste produced from reprocessing e.g. fines produced from crushing processes.
- The market available for purchasing the demolition materials.
Interpretation of the definition of waste can mean that even after processing and recovery, a material can still be classed as a waste. The Quality Protocol is a guidance document for producers and purchasers of aggregates from various inert wastes, including demolition materials.
Crest Nicholson worked with demolition experts in the Park Central case study provided. The Crest Nicholson case study, ‘Construction Waste Management Plans’ shows that as a result of a screening process, materials that would have been landfilled were put to productive, commercial use.
Corus Construction provides a case study of how a 53 year old building was demolished and the steel recycled into new products.
3. What pollution issues should I consider?
The end of life stage also takes into consideration pollution stemming from particulate matter expelled in the atmosphere from demolition, processing, and transport of materials from site. Dust and noxious substances can adversely affect the following.
- The natural environment, e.g. nearby vegetation corridors.
- Human health, e.g. aggravating asthma attacks.
- Community quality of life during demolition activities.
It is important to observe legislation (i.e. local legislation such as Local Air Pollution Control and Local Air Pollution Prevention and Control (LAPC/LAPPC)), and available good practice to control dust and particular matter resulting from the end of life processes (i.e. the Building Research Establishment (BRE) Pollution Control Guides). Moreover, noise, vibration and visual agitation can be disturbing to the community around the site. It is important to consult with the local authority for guidance to minimise the impacts on people that are associated with activities at the end of life stage.
Are there key considerations we haven’t included? If so, please let us know.
The following are a set of questions you should be asking yourself at this stage of the construction process.
- Is demolition the right choice?
Has the original building design catered for changes in use or additional floors/extensions
What is the flexible capacity inherent within the existing building to adapt to a change in use or to conform to modern standards
Has a comparison been made between the impact of demolition and rebuild versus refurbishment and adaptation?
Can the building be reconfigured or adapted to perform for a different function? - How can demolition materials be reused or recycled?
Is there a local need for any of the materials arising from the demolition?
Did the original design cater for deconstruction and reuse? Can materials be reclaimed without unnecessary demolition?
Do both the demolition Client and Contractor fully understand the building to be demolished e.g. the structure, plant and materials that can be reclaimed? - Are there savings at the end of life for a sustainable building?
Can the building be sold on when it is obsolete to host its current function?
Are their savings or gains to be made from recycling materials?
How can materials be exported to landfill be minimised? - How will the risks of contamination to the site be mitigated?