Pre-refurbishment/renovation or pre-demolition audits ("waste audits")

Pre-refurbishment/renovation or pre-demolition audits, sometimes known as "waste audits", are commissioned to evaluate recovery and waste management options resulting from the anticipated construction activities.

---

In ideal conditions, pre-refurbishment/renovation or pre-demolition audits should be performed before the call for tenders or choosing the contractor. This can prevent companies responsible for work from being at risk of additional unforeseen costs, such as, for instance, the handling of hazardous materials not identified before commissioning the work.

---

Such audits include:

• the amount and type of construction material/products that will be deconstructed/demolished;

• an assessment of possible reuse or recycling of the above considering all relevant legislation;

---

In this step, any risks related to handling hazardous substances should be identified.

---

• additional information (if needed) on, for example, the estimated value of materials/products for reuse or the estimated waste handling costs.

---

So far, there is no standardised way of performing pre-refurbishment/renovation or pre-demolition audits in the Nordics or the EU. More information on "waste audits" in Denmark, Finland, and Sweden can be found here.

---

General steps in "waste audits"

Step 1: Decision on the audit scope

• before starting the audit, the decision on the work (refurbishment/demolition) scope must be made (i.e., what part of the building will be involved in the work);

• specify the goals regarding resource management (i.e., targets on reuse and recycling of materials and products and (if applicable) their possible use in other projects);

• specify additional requirements for the audit, such as, for example, the estimated value of materials/products for reuse or the estimated costs of waste handling depending on the route of their utilisation.

Step 2: Desk research

• it aims to gather as much data on the building and its elements as possible to plan the next step (field visit) as well as possible;

---

In this step, any risks related to the presence of hazardous substances should be identified. Here, you can find information on hazardous substances in Iceland's construction and demolition waste.

---

In Denmark, the list of possible hazards linked to the type and age of various materials/products is presented in the VCØB's Material Atlas.

---

• its outcome should be a first draft of materials and products inventory, including uncertainties related to them, which need to be checked during field visit;

• data that should be collected (at least) is as follows:

  • building location and surroundings (to assess accessibility, plan future selective demolition and logistics of waste handling, including proximity of material/product storage or waste management facilities);

  • building age (to adjust expectations on materials and products to historical qualities and past techniques used in case design documents are not available);

  • as-built documents (available architectural plans and technical drawings useful for preliminary assessment of dimensions, construction typology, type of materials, location of invisible elements, e.g., installations, details of spaces difficult to access);

  • use documentation (to provide information on previous modifications to the building, i.e., refurbishments, repairs, maintenance, or incidents, e.g., fire or accidents which might have influenced material/product types and quality);

  • materials/products documentation (to provide information on the source, type, quality, lifespan, possible hazards and ways of handling materials and products present in the building);

---

Assessment of the hazardous substances to expect should be included based on existing documentation (e.g., asbestos inventory, accidents/spills register) or measurements done by the auditor if no documentation is available. The measurements are crucial to ensure safety during the field visit by adjusting means of protection to the hazards present.

---

• certification documents (if applicable; it provides additional information on materials and products used as well as might include assessment of their possible reuse or recycling ways);

• the above information can be found in, among others, the building owner archives, fire safety plans, municipality archives (e.g., Skjalasafn Reykjavíkur), Mannvirkjaskrá or digital data from online platforms, e.g., Google maps.

Step 3: Field visit

• it aims to visually inspect the premises, verifying the previous findings and plans drawn based on the gathered documentation and other data, and initially plan selective demolition process and possible ways of waste recovery.

---

Access to the premises must be guaranteed. Any spaces unavailable for access (e.g., due to collapsed walls, deteriorated stairs, or hazardous substances present) must be noted in the audit report.

---

Any materials and products covered by Extended Producer Resposibility (EPR) must be identified and managed accordingly.

---

• not all materials and products are easily identifiable visually, and often, sampling and testing are necessary:

  • visual inspection and non-destructive testing methods (e.g., near-infrared (NIR) spectrometers, metal detectors, X-ray fluorescence (XRF) scanners) are usually used for assessing the level of degradation and damage and presence of hazardous substances;

  • destructive testing methods (e.g., removing surface coating or drilling to check the element composition at various depths) are usually used to determine the nature of certain materials or products (e.g., chemical composition).

Step 4: Material and product inventory

• the inventory of present materials and products is the most important output of the pre-demolition audit as it gives a foundation for the following works (i.e., selective demolition);

---

In the EU Construction & Demolition Waste Management Protocol including guidelines for pre-demolition and pre-renovation audits of construction works (Annex C), you can find suggestions on how to organise such inventory.

---

• it is advised to complement the inventory with relevant photographs, which might aid further works (e.g., renovation, demolition).

Step 5: Recommendations on resource management

• the prepared recommendations should include at least the following:

  • as detailed as possible information on how to sort materials and waste on-site;

  • detailed information on the ways (sometimes several alternatives for certain materials/products) of their further recovery or disposal and various ways potential;

---

More information on the potential for utilisation of construction and demolition waste (C&DW) in Iceland can be found here. It is, however, worth keeping an eye on Icelandic waste management companies and other stakeholders from the construction sector working on extending the possibilities of recycling or reusing C&DW, as soon there might be more possibilities in the market.

---

• a list of legal requirements which need to be followed, also indicating which materials/products/building elements they correspond to;

• a comprehensive information of possible risks related to deconstruction and ways of mitigating these;

• indication of possible diversions from the planned resource management plan and ways of mitigating these.

---

In Iceland, following Byggingarreglugerð (15. Mengun frá mannvirkjum og meðhöndlun byggingar- og niðurrifsúrgangs), a construction and demolition waste management plan is required when applying for the building permit.

Some certification schemes (e.g., LEED) also require the preparation of such a document. Such a document can aid the pre-demolition audit but cannot replace it due to its usually narrower scope.

---

Step 6: Reporting

• the report summarises the findings from the previous steps and must include at least the following:

  • summary of the project (i.e., its owner, scope of work);

  • summary of the desk research (i.e., history of previous renovations/modifications, uses);

  • summary of the audit (i.e., comprehensive summary of the data collected, preferably expressed in numerical values on, for instance, mass of volume of waste generated, estimated mass, area, or volume of materials suitable for reuse);

  • list of the documents and other materials (e.g., photographs, site plans) used within the audit;

  • inventory of identified materials and products;

  • information on any hazards related to handling the identified materials and products with ways to mitigate these;

  • resource management recommendations.

Sources and further readings:

1)    EU Construction & Demolition Waste Management Protocol including guidelines for pre-demolition and pre-renovation audits of construction works, 2024.

2)    M. Wahlström et al., Pre-demolition audit - overall guidance document, 2019.

3)    G. Brusa Cattaneo G et al. Circular Construction for Urban Development, 2024.

4)    Level(s) indicator 2.2: Construction and Demolition waste and materials User manual: introductory briefing, instructions and guidance (Publication version 1.1), 2021.

5)    M. Wahlström et al., Improving quality of construction & demolition waste- Requirements for pre-demolition audit, 2019.