It consists of a manual that will allow technicians to estimate the quantities and types of waste that will be generated on any construction site.
Construction and demolition waste (CDW) represents approximately one third of the total waste generated in the European Union.
In order to properly manage this waste and ensure that it can be recycled into other materials, it is necessary to carry out a good study in all construction and demolition projects, as established in Royal Decree 105/2008. This study should include the types and quantities of waste that are expected to be generated, as well as the measures envisaged for the separation of each type of waste and its correct management.
In order to support all agents in the sector in classifying these materials at origin, the General Council of Technical Architecture of Spain (CGATE) and the High Council of Architects (CSCAE) have published a guide with estimated national ratios of construction and demolition waste generation.
The analysis combines normative values at regional or local level, statistical data series and real values. Since the number and location in the territory of the data series analysed per autonomous community is variable, their comparative analysis is grouped according to the differential characteristics of the construction for the large climatic regions of the territory in order to enable a more intuitive and general use of the data contained in the tables.
This CDW Ratios Guide is the result of the joint work of the Bilateral Commission created by both Councils to try to find a solution to the dispersion of CDW.

Resources needed

To create the guide ratios, sector experts have consulted databases of renowned entities, regional & local regulations have been considered and information has been actively requested from the most relevant agents in the sector. Guide is openly available to use in climatic zones similar to Spain.

Evidence of success

The main evidence is that it is a general support to the technician in the definition of CDW ratios for his/her project, leaving the identification of the most suitable geographical-climatic zone for the location of the building and the adjustment of the general ratios provided to the singular characteristics of the building to the technician's discretion.
It can also be noted that these ratios have been used for a tool developed in the CONDEREFF project for the exchange of experiences.

Difficulties encountered

This is a national level initiative, so the ratios are mainly aimed at projects within the Spanish region based on its climate and construction conditions. In addition, the guide is currently only in Spanish, which may hinder the exchange of experiences with other regions.

Potential for learning or transfer

This manual also serves as a guide for the future Spanish Waste Law, which in its draft establishes that, as of 1 January 2022, construction and demolition waste must be classified into at least the following fractions: wood, minerals (concrete, bricks, tiles, ceramics and stone), metals, glass, plastic and gypsum, classification to be carried out preferably at the origin where the waste is generated.
The beneficiaries of the results of the analysis and processing of the data collected are the construction technicians responsible for the drafting and/or monitoring and acceptance of the technical documents linked to the compliance with RD 105/2008 that contemplate the pre-construction estimation of the quantities of CDW to be generated in the different Waste Management Study and Waste Management Plan.
This is an initiative that can be replicated in other regions in order to enhance better waste treatment and promote the circular economy.

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Main institution
Comunidad de Madrid, Spain (España)
Start Date
June 2020
End Date


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