Environmental Impacts of Multi-Storey Buildings Using Different ...

- 120 -Embodied energy.Embodied energy would be calculated from a building-specific listing of the major building materials,converted into gross quantities (for instance, as documented in a Quantity Surveyor’s report) and crossreferenced with an appropriate, simplified LCI with data applicable to NZ.Note that only the major building materials would be considered – this could be defined as those materialswhich contribute to more than a specified percentage of the building by mass or volume. It would mostlikely, in most instances, consider at least concrete, steel, timber, glass, aluminium, paint,particleboard/fibreboard, gypsum board, masonry and insulation.This recognises the environmental impact of producing / manufacturing building materials. Results wouldhighlight materials which have a significant embodied energy “cost”.Initial embodied CO 2 would be calculated by cross-referencing appropriate LCI data for the significantmaterials listed above (for instance, VUW data sets).Recurrent embodied energy.This recognises the environmental impact of maintenance, refurbishment and replacement of buildingmaterials. Results would highlight materials which have a significant embodied energy “cost” over the lifetimeof a building beyond the initial construction, due to the need for frequent maintenance or replacement(but possibly demonstrating less initial environmental impact).Recurrent embodied CO 2 would be calculated by cross-referencing data on maintenance and replacementcycles for the most commonly used materials.Net embodied CO 2 .Overall net embodied CO 2 would be calculated from initial embodied CO 2 , plus any chemical release ofCO 2 during the manufacturing process, less CO 2 sequestered and then combined with recurrent embodiedCO 2 . Initial and recurrent embodied CO 2 could be detailed separately.Net CO 2 – that is an emission to the atmosphere or a sequestration with removal of CO 2 from theatmosphere – is the primary focus of both national and international initiatives to address climate change.Measurement of net embodied CO 2 recognises those materials and processes that remove CO 2 from theatmosphere on a permanent (sustainable) basis.Utilising Victoria University LCI data for building materials offers a “CO 2 footprint” for most common NZbuilding materials and captures the effect of CO 2 emissions during the manufacturing process (for instancein cement production), as well as sequestration (for instance in timber products).________________________________________________________________________9.7 Timber used in the Buildings.Structural LVL dominates the quantity of timber used in the buildings. Other timber andtimber components are used throughout all the buildings but much more so in the Timber andTimberPlus designs.9.7.1 Laminated Veneer LumberThe Engineered Wood Products Association of Australasia provides excellent information onmany of the engineered wood products currently available commercially in New Zealand (andAustralia) (http://www.paa.asn.au).LVL is a hugely versatile timber product of known and consistent physical and mechanicalproperties, able to be manufactured to chosen specifications, including large dimensions.