Gaps in selective demolition
“Guest column” by Mr. David García, Researcher in coordination team of HISER project.
Valuable raw materials are available within demolition wastes. The actual characteristics of those stocks depend on the demolition process producing those wastes. And, as such, it is also determining the feasibility and economics of the recovery of those raw materials.
According to demolishers, demolition is in itself a waste management process. Furthermore they know how to take the best out of the building at its end-of-life. Nevertheless, the demolition world is complex and evolving. Ever more complex construction materials are appearing in demolition or refurbishment works, such as insulation materials or composites, which are sometimes difficult to recognize and often there are no established recycling routes for them yet. Limited access to buildings prior to works, short work periods, a subordination of demolition works to constructions works, subcontracting of demolition activities based on solely economic criteria, the regional legal framework and the availability of recycling or waste management facilities, amongst others, lead to random success in performing efficient demolition.
HISER project aims to identify and prioritize existing technical and non-technical gaps in current practices for smart demolition of buildings hampering a higher level of onsite sorting and recovery of valuable waste materials. The gathering of dedicated data with European perspective allow us to define and harmonize current existing needs constituting the basis for the development of novel procedures, guidelines, smart tools and policy recommendations.
One of the objectives of the HISER project is to develop solutions and provide tools that will contribute to cost-effective and highly efficient demolition, particularly a BIM-based software tool and a tracking system. In this line, the European Commission has just launched an action for “Developing a Common EU Construction & Demolition Waste Management Protocol”. HISER is facing the design of new solutions on the basis of a comprehensive study of the current situation of demolition and refurbishment works across Europe, which has been performed by means of dedicated interviews with demolition sector experts and one workshop organized within the annual meeting of the European Demolition Association, EDA.
Questions about conditions for the planning of demolition works (involving pre-demolition audits, permits, budgeting, etc.), particularities of works depending on the type of buildings and urban/rural environment, wastes occurring at their works, onsite sorting practices, legal requirements, equipment, personnel training, certification and supervision of demolition works or transport and processing of materials were answered by 44 individual interviewees (39 of them face-to-face). Some recurrent affirmations are included below:
- There is a clear necessity of more accurate inventory, which conditions the waste management plan.
- In some countries it is difficult to find a recycling plant nearby the demolition project. This, in combination of low prices for landfill, hampers selective demolition, onsite sorting and efficient recovery of materials. The governments should take a big part in this.
- There is a need for information to give proper training for personal. Personal should be more aware of what selective demolition contents. This can seriously induce cost savings.
- Recycling targets are becoming tighter. New innovative mind-set and approach is necessary as well as new technical developments.
The workshop titled “Selective demolition: current practices and innovation” provided another opportunity to discuss those subjects first-hand with demolition contractors. During this event, experts expressed concern about three important steps which are currently not well connected and should be improved:
- Pre-demolition audit (inventory)
- Waste management reporting
- Final waste management report
Interest on recycling technology has been raised by some participants. Considering that demolition represents an important stage in the value chain (from EoL construction to recycled materials), they are willing to be informed on future technology development ongoing within HISER.
In addition, EDA members suggest that in order to create a market for recycled materials, it is necessary to stimulate the consumption of those recycled materials, e.g. glass or insulation materials. A possibility could be to impose minimum contents of recycled material in a construction material product. To improve the market attractiveness of waste management, consensus among HISER and EDA members was expressed about the necessity to shorten the value chain.
The obtained conclusions will be used to define the functional requirements of an intelligent BIM tool for smart selective demolition, to be developed along 2016. This tool will allow us to digitalize existing buildings by means of different starting points (DXF, Google Earth/maps, photo modelling, laser scanning, etc.) to obtain precise geometries, quantification and location of materials, etc. to estimate material composition of a given building, to assist on best solution for waste materials treatment, to schedule activities, resources and machinery, etc. according to material type, legislation, fees and costs.
HISER “Holistic Innovative Solutions for an Efficient Recycling and Recovery of Valuable Raw Materials from Complex Construction and Demolition Waste” is an ambitious project around closed material loops for Construction and Demolition Waste, based on circular economy principles. The project was designed addressing the specific challenges and scope described by the European Commission in the call Recycling of raw materials from products and buildings (Waste 3-2014), around the main pillar of societal challenges. This project has received funding from the European Union’s Horizon2020 research and innovation programme under grant agreement No 642085.