Sung Kin Pun

Case study of demolition costs of residential buildings

Building demolition is one of the most common activities in the construction industry. Several demolition techniques are commonly used, including mechanical demolition, deconstruction and hybrid demolition. Although deconstruction has been advocated for its environmentally friendly approaches, the cost comparison of a demolition project under different techniques is rarely researched. In this paper, the cost of a demolition project is broken down to input and output costs, which are further broken down to more countable sections. Through an empirical study in Victoria, Australia, project costs of mechanical demolition, hybrid demolition and deconstruction are investigated. It is found that deconstruction has the greatest profitability among the three techniques. Hybrid demolition, which is the actual technique adopted by the contractor, has a slightly lower profit, and mechanical demolition is the most expensive. Although deconstruction has the best overall economical performance, the small extra gain comes with increased complexity and risk that deters demolition contractors from its attempt. It is found in the paper that an optimized demolition project strategy exists between hybrid demolition and deconstruction with the greatest profitability among various building demolition techniques.

Electronic Waste Exchange for Just-in-Time Building Demolition

Abstract Waste exchange is as a facilitator for construction and demolition waste deduction by reuse and recycling in construction projects. The just-in-time philosophy, which has been well cultivated in the manufacturing industry, is highly adoptable for demolition projects. Particularly, waste exchange that is usually performed after the actual demolition process can be shifted forward so that waste inventory from demolition is eliminated or reduced to facilitate waste reuse and recycling. A web-based waste exchange system is an ideal platform to enable communications among project participants before a demolition project commences so that waste materials can be sold before they are produced. Therefore, the productivity of the demolition project could be improved. This research paper aims to investigate and analyse the adoption of just-in-time philosophy in building demolition project management. It also describes the development of the proposed web-based waste exchange system that implements just-in-time demolition in detail, including its functionalities, information flows and major components.

Information System Development for Demolition Material Management

In recent years, the increasing pressure of environmental requirements, including the reduction of waste, has widely challenged various industries worldwide. Most industrialised countries, including Australia, have achieved high levels of consumption and correspondingly high levels of waste disposal. Australia has the second highest domestic waste production per capita among all member nations of the Organization for Economic Co-operation and Development as published in the web page of the New South Wales Environment Protection Authority (2003). Nearly one tonne of solid waste is sent to landfill per person each year as the total waste stream in Australia is about 14 million tonne of which somewhere between 16% and 40% is construction and demolition waste (Reddrop and Ryan, 1997). This number was 33% in the Barwon region of Victoria in 2002. The demolition of building structures produces enormous amounts of materials that in most countries result in significant waste streams. The construction industry, particularly in the demolition of constructed facilities, is the top contributor among all industry sectors to these levels of waste.