Search

Due to poor design of buildings in terms of maintenance, there are a number of buildings today that remain extremely expensive to maintain, both economically and environmentally. In order to mitigate these overheads, the development of a cost database is needed with which the resources required to clean and maintain buildings can be estimated. This paper presents a methodology to estimate these costs and the environmental impact, in terms of Ecological Footprint (EF), associated to the utility consumption and to the cleaning tasks necessary during the service life of buildings. Given the numerous peculiarities identified for this type of activity compared to the construction of buildings, it is necessary to define a new methodology of calculation, with its own assumptions and formulae. This methodology is then applied to the case of a college hall of residence that houses up to 139 residents. The results show that the annual EF of cleaning tasks accounts for 11.42% of the EF of utility consumption. Together they total 67.334 global hectares per year (gha/yr), 88% of which corresponds to the carbon footprint. Within the EF of cleaning, about 71% is due to food consumed by labor, while 26% is due to the manufacture of cleaning products and tools, which are equally divided among the six categories of productive land. The development of this methodology is essential for the detailed quantification of the environmental impact of utility consumption and cleaning tasks that occur during the service life of buildings. The use of discount rates on results is included in terms of the EF of a baseline year, as an equivalent to the discount rate in economic terms.

The construction industry is well known for its high impact on the environment; an even higher impact has taken place in recent years due to the real-estate bubble which has resulted in a surplus in the construction of dwellings in many countries. In Spain, about 500,000 dwellings were constructed during 2006–2010, which represent a 2% increase in four years. In the present work, a methodology is defined as the first step towards the creation of an effective assessment of the Ecological Footprint of this type of construction. The procedure is based on the project budget and its bill of quantities, organized by means of a systematic construction-work breakdown structure which divides the work into three major categories: materials, manpower, and machinery. Each stream generates partial footprints (i.e. energy, food, mobility, construction materials, and waste). Ninety-two dwelling construction projects, which represent the most commonly built dwellings in Spain per statistical data from the authorities, are evaluated and their ecological footprints are determined. The indicator is sensitive to various building typologies, which range from detached houses to multi-family buildings. Detached houses generate an ecological footprint per square metre constructed of 1.5 times higher than that of 4-floor multi-family buildings and the indicator remains practically constant for taller buildings. This emphasises that not only is the traditional Spanish construction of a compact city with multi-storey buildings environmentally better from the mobility standpoint, but also from the building construction standpoint.

Construction activity is now a major consumer of natural resources. As a general rule, resource consumption has been evaluated through methodologies related to Life Cycle Analysis. This research is proposed to integrate the Ecological Footprint indicator into the building sector: to observe the difficulties and the benefits it can generate relative to other indicators. To this end, prior knowledge related to the Ecological Footprint indicator must first be adapted to the residential sector, by analyzing the construction of buildings, and secondly a calculation methodology is established in order to quantitatively determine what impacts are generated by industry according to the Ecological Footprint indicator. This methodology applies the indicator to resources used (energy, water, labour, construction materials, etc.) and to waste generated in the construction of residential buildings. The methodology is applied to a case study corresponding to the urbanization and building construction of a representative building type in Andalusia (Spain) when the building is in the planning stage. The final result is 0.384 gha/year/m 2 .