The efficient use of materials in regeneration projects

Transcription

1 Linking demolition and new build a step by step guide The efficient use of materials in regeneration projects 10. Demolition phase The Demolition phase section outlines the planning of the demolition activities from a materials resource efficiency viewpoint as well as the principles and processes of setting and monitoring the demolition phase KPIs. This information is of use to architects, designers, new build and demolition contractors. Demolition contractors who respond positively to a client s materials resource efficiency objectives and requirements increase the likelihood of winning contracts, saving money, developing new services and ensuring that the objectives, requirements and benefits are achieved. Actions: ensure that core materials resource efficiency features are understood; take account of materials resource efficiency in planning of demolition activities; and collect data and calculate KPIs. Who needs to act? Architects Designers Contractors Demolition Contractors. Contents 10.0 Introduction Factors to consider in planning demolition activities Demolition monitoring Example calculation of demolition KPI values 06

2 02 The efficient use of materials in regeneration projects: 10. Demolition phase 10.1 Factors to consider in planning demolition activities Initial planning of the demolition works can be undertaken at the design stage by designers reviewing the feasibility of on-site reclamation and recycling of materials. For best results this should involve the demolition contractor. Detailed planning should start as soon as the demolition contract has been let. This section is primarily of interest to demolition contractors, but also to other parties such as designers and contractors. The factors to be considered in the planning of demolition activities include: type and quantity of materials arising. A pre-demolition audit provides a listing of the types and quantities of materials that will be produced. This data can be used to develop the SWMP for the demolition works and enable effective demolition planning. For example, the audit results guide the types of equipment required and the extent of on-site storage; type and quantity of materials required in the new build. When optimising the type and quantity of retained materials it is important to consider the material required for the new build. This also influences the demolition planning; collection of data for KPI calculation. This data is used to demonstrate that the project requirements have been exceeded and monitor material recovery performance through the Site Waste Management Plan. Data collection methods need to be agreed before the demolition commences, for example waste transfer notes, or the measurement of on-site stockpiles;

3 The efficient use of materials in regeneration projects: 10. Demolition phase 03 local demand for recovered materials. When the quantity of materials produced by the demolition exceeds the quantity required by the new build, it is important to ensure that there is a local demand for the materials. If there is no local demand, it may be better to produce an alternative recycled product for which there is a local market; range and capacity of equipment. Once the materials to be produced on-site have been identified, then suitable equipment with the required capacity has to be identified; size and layout of site. The size and layout of the site may restrict the type and quantity of materials that can be produced and stored on-site, (as can the new build programme). For example, considerable amounts of retained material may be usable in the landscaping, but if the stockpiling of the retained material will interfere with the construction this may not be an option. An alternative to transporting the material to a distant recycling facility is to set up a local temporary facility for processing and stockpiling of the retained materials. Waste management licensing needs to be addressed for this temporary facility. The AggRegain demolition and recycling infrastructure modules and the ICE Demolition Protocol present guidance on the size and layout of on-site recycling facilities. The AggRegain web pages also contain information on Waste Management Licensing; transportation. The extent and type of transportation of materials off-site needs to be assessed to identify possible reduction of lorry movements; this may promote further on-site reclamation and recycling of materials. If the site is sufficiently large that the demolition is still on going-on one part of the site whilst new build construction is being undertaken on another, the transportation of material on-site needs to be planed; contamination. Potential contamination of the recovered materials has to be considered; the ICE Demolition Protocol provides extensive guidance on possible contamination;

4 04 The efficient use of materials in regeneration projects: 10. Demolition phase hazardous materials. Hazardous materials, or possible contamination with hazardous materials, has to be assessed. The demolition procedure has to consider hazardous materials from a Health and Safety viewpoint and to avoid any contamination of the recovered material produced. This should be assessed as part of the pre-demolition audit; and Health and Safety. Health and Safety issues can have a considerable impact on the level of material recovery in a demolition project. Issues such as the presence of hazardous materials, the nature of the structure, safe access for operatives, and its proximity to the public need careful consideration when planning the works and material recovery possibilities. Further information on these factors is presented in the WRAP Construction and AggRegain web pages.

5 The efficient use of materials in regeneration projects: 10. Demolition phase Demolition monitoring The demolition must demonstrate that it meets the KPI requirements for the Demolition Recovery Index (DRI) and Retained Material (RM). This is normally undertaken towards the end of the demolition phase of the project. This section is primarily of interest to the contractors undertaking the demolition. During demolition it is important to collect data allowing the DRI and RM KPIs to be calculated. These KPIs can be calculated from the Site Waste Management Plans (SWMP) categories as shown in Figure 10. When calculating the DRI and RM quantities, the amount of material sent to a materials recycling facility (MRF) is required for the calculation. The level of material recovery achieved at these facilities can vary therefore an assumption of the facility s performance must be made. If no information is known about the facility then a default recovery rate of 65% should be used. Making an enquiry to the MRF may identify processes that increase the recovery rates to good practice levels (around 80%) or even best practice levels (upwards of 90%). If the data sets have been collected for the Site Waste Management Plan, then data can be used to calculate the RM quantities. If not, establishing the quantities of materials sent off-site can be calculated from waste transfer ticket records. Establishing the recovered materials retained for use on-site can be undertaken using standard quantity surveying techniques of the material stockpiled on-site. Introductory guidance is presented in WRAP Construction and AggRegain web pages and in guidance such as Deconstruction and reuse of construction materials produced by BRE.

6 06 The efficient use of materials in regeneration projects: 10. Demolition phase Using site data to calculate KPIs Demolition Recovery Index (DRI) The KPI can be easily calculated from the Site Waste Management Plan (SWMP) materials categories as shown in Figure 10. However, some care is needed with calculation units. An example of this calculation is shown below. Retained Material (RM) The KPI can be easily calculated from the SWMP materials categories as shown in Figure 10. An example of this calculation is shown below. How to collect data and calculate demolition KPIs Categorise demolition material SWMP categories Re-used on-site (a) Recycled for use on-site Re-used off-site (a) Recycled for use off-site Sent to recycling facility Sent to WML exempt facility Disposed to landfill Sum Quantity (Q1) Sum Quantity (Q2) Sum Quantity (Q3) (Q1 + Q2) / (Q1 + Q2 + Q3) (Q1) (Q1 + Q2) Demolition Recovery Index Retained Material quantity Notes: (a) Reused material = Recycled materials Reclaimed Materials + Recycled Material = Recovered Materials Reused on-site Recycled for use on-site Reused off-site Recycled for use off-site Sent to recycling facility Sent to recycling facility this includes materials reclaimed from the demolition process this includes materials processed on-site this includes reclaimed materials processed on other construction sites this includes materials processed on other construction sites this includes materials sent to materials recovery facilities (MRF) to be reclaimed or recycled this includes materials sent to WML (waste management licence) exempt facilities as an alternative to landfill disposal Figure Example calculation of demolition KPI values The example opposite demonstrates how the KPI requirements set for the DRI and the RM are met. This would normally be undertaken towards the end of the demolition phase of the project. This section is of interest to contractors undertaking the demolition.

7 The efficient use of materials in regeneration projects: 10. Demolition phase 07 Case study Wembley Link Development The Wembley Link Development Project forms an important part of the overall Wembley area regeneration. The Link Development consists of a new overbridge, a marshalling area and a number of key plots with frontage around the Stadium and Wembley Triangle. The project aims to improve connections and regenerate the area between the National Stadium and Wembley Town Centre. As part of the works, several buildings were demolished. This example demonstrates how the materials arising from the demolition of Network House (a three-storey, concrete framed office building) were measured. Using data from transfer tickets and estimation of on-site stockpiles, a demolition Bill of Quantities was produced. Part of this Bill of Quantities is shown below: Recovered Items Quantity arising (tonnes) Recovery (%) Recovered on-site (tonnes) Recovered off-site (tonnes) Concrete Tonnage disposed (tonnes) Nonconcrete masonry Wooden joists, floors Miscellaneous wood Structural steelwork External tiling Totals 2840 Tonnage recovered for use on-site (Q1) 40 Tonnage recovered for use off-site (Q2) 913 Tonnage disposed (q3) Demolition Recovery Index (DRI) (Q1 + Q2) / (Q1 + Q2 +Q3) Retained Material (RM) Q1 / (Q1 + Q2) 76% 99% Figure 11 Additional resources (See section 14) AR1 AR9 AR10 AR13 AR14 AR16 AR18 WRAP, The Demolition Protocol (Volume 2: Developer and Designers, Volume 3: Contractors). WRAP, Construction web pages. (demolition). WRAP, AggRegain web pages (demolition, recycling, infrastructure, waste management licensing). DTI, Site Waste Management Plans. ICE, The Demolition Protocol. CIRIA, CIRIA C529: Environmental Handbook for Building and Civil Engineering Projects: Part 3 Demolition and Site Clearance. BRE, Deconstruction and reuse of construction materials.

8 This is one of a series of booklets which together form WRAP s guide: The efficient use of materials in regeneration projects. While this booklet is designed to be used separately it may refer to sections in the main guide. This report has been published in good faith by WRAP with the help of Scott Wilson Ltd, and neither WRAP nor Scott Wilson Ltd shall incur any liability for any action or omission arising out of any reliance being placed on the report by any organisation or other person. Any organisation or other person in receipt of this report should take their own legal, financial and other relevant professional advice when considering what action (if any) to take in respect of any initiative, proposal, or other involvement with any procurement process, or before placing any reliance on anything contained therein. By receiving the report and acting on it, any party relying on it accepts that no individual is personally liable in contract, tort or breach of statutory duty (including negligence). While steps have been taken to ensure its accuracy, WRAP cannot accept responsibility or be held liable to any person for any loss or damage arising out of or in connection with the information in this report being inaccurate, incomplete or misleading. The listing or featuring of a particular product or organisation does not constitute an endorsement by WRAP and WRAP cannot guarantee the performance of individual products or materials. For more detail, please refer to our Terms and Conditions on our website Waste & Resources Action Programme The Old Academy, 21 Horse Fair, Banbury, Oxon OX16 0AH Tel: Fax: info@wrap.org.uk Helpline freephone Printed on 75% recycled content paper When you have finishe