Construction and demolition waste (CDW)

Construction and demolition waste (CDW) is the waste generated during building work, refurbishments, demolitions and excavations. It is one of the largest waste streams in Spain and the European Union: according to the European Commission, the construction sector is responsible for around 35% of all waste generated in the EU.

Spain's Law 7/2022 on waste and contaminated soils for a circular economy defines CDW as the waste produced in construction, demolition, refurbishment and excavation works.

Royal Decree 105/2008, of 1 February, specifically regulates its production and management, requiring the different fractions to be separated at source and giving priority to recovery.

Managing CDW well matters for several reasons:

• Its huge volume, which fills up landfills if it is not recovered.
• The opportunity to recycle materials such as aggregates, metals, wood or plastics.
• Its environmental impact, since poorly managed CDW causes uncontrolled dumping, contamination and the needless occupation of land.

Types of CDW

Inert CDW

• Concrete, bricks, tiles, ceramics and stone.
• It undergoes no significant chemical transformation.
• It can be recycled as aggregates for fill and roads.

Non-hazardous CDW

• Wood, plastics, metals and gypsum.
• It requires separation and specialised treatment.

Hazardous CDW

• Asbestos (asbestos-cement sheeting).
• Paints and varnishes containing lead or solvents.
• Tar-impregnated materials. Their management is subject to strict safety protocols.

Regulatory framework

• Waste Framework Directive (2008/98/EC).
• Royal Decree 105/2008 on the production and management of CDW.
• Law 7/2022 on waste and contaminated soils.
• Regional legislation (specific CDW management plans).

Royal Decree 105/2008 requires:

• A CDW management study for every construction project.
• A deposit or guarantee to ensure waste is managed correctly.
• Priority for recycling and recovery over disposal.

Collection and management systems

Separation at source

• Separate containers on site for concrete, metals, wood, plastics and hazardous waste.
• This improves the quality of the recycled materials.

Transport to treatment plants

• CDW moved by truck to authorised facilities.
• Control through identification and traceability documents.

CDW recycling plants

• Crushing and screening of concrete and ceramics.
• Separation of metals using magnets.
• Sorting of wood and plastics for recovery.

Final destination

• Recovery: recycled aggregates, biomass and recovered metals.
• Disposal: inert-waste landfills (the last resort).

Benefits of efficient management

1. Environmental: less illegal dumping, lower landscape impact and reduced extraction of natural aggregates.
2. Economic: cost savings in public works through recycled aggregates, new business opportunities in recovery plants and green job creation.
3. Social: fewer illegal dumps on the urban fringe and greater social acceptance of sustainable construction projects.

Risks and penalties

• Uncontrolled dumping of CDW on tracks and vacant plots.
• Failure to separate at source.
• Mixing hazardous and non-hazardous CDW.

Under Law 7/2022, very serious infringements can carry fines of up to 3.5 million euros.

CDW and the circular economy

CDW is a priority stream in the circular economy:

• It allows large volumes of material to be recovered.
• It reduces the extraction of natural resources.
• It encourages industrial symbiosis in the construction sector.

Conclusion

Construction and demolition waste is one of the biggest challenges, and at the same time one of the biggest opportunities, in waste management in Spain. Sound management based on prevention, separation at source and recovery can turn an environmental problem into a valuable resource: a source of secondary raw materials for a circular construction sector. At Manglai we help companies measure their environmental footprint and prepare their sustainability reporting. Discover how Manglai can help you.