Environmental evaluation of energy efficiency refurbishment in New Zealand's commercial office buildings : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Science in Life Cycle Management at Massey University, Manawatū, New Zealand

In New Zealand, 80 % of existing commercial office buildings are more than 20 years old and consume approximately 40 % more energy than newer counterparts. Moreover, nearly 38 % of the energy-related emissions in New Zealand’s cities are due to the heating and cooling requirements of commercial office buildings. Therefore, energy efficiency measures in office buildings are recommended to reduce operational energy related costs, provide better working conditions, and enhance business value. An energy efficiency refurbishment which involves adoption of multiple energy saving measures such as thermal insulation, improved glazing, air conditioning and lighting systems, can reduce the energy consumption of existing buildings by nearly 60 %. However, such a refurbishment also involves substantial construction work associated with the demolition and replacement of several building components, and this is associated with additional environmental impacts. It is therefore important to evaluate if the environmental benefits associated with reductions in energy demand can outweigh the environmental impacts of refurbishment. This research investigated the comprehensive environmental impacts of energy efficiency refurbishments in New Zealand’s office buildings using Life Cycle Assessment (LCA). The research used existing data collected for Building Energy End-use Study (BEES) by the Building Research Association of New Zealand (BRANZ). In particular, this research used the information on building design and annual energy consumption of existing and refurbished building prototypes. These building prototypes provided - construction details adopted in buildings of different sizes; and the operational energy performance based on typical climatic conditions found in New Zealand. The environmental performance of the buildings was calculated for Global Warming Potential (GWP), Ozone Depletion Potential (ODP), Photo-chemical Oxidation Potential (PCOP), Acidification Potential (AP), Eutrophication Potential (EP), Abiotic Depletion of resources (ADr), Abiotic Depletion of fossil fuels (ADff), Human toxicity carcinogenic (HT-carc), Human toxicity non-carcinogenic (HT-non carc), Eco-toxicity freshwater (ETfreshwater), Particulate Matter Formation (PMF), and Ionizing Radiation (IR). A series of studies were performed to: (i) assess the environmental impacts and identify the environmental hot-spots of energy efficiency refurbishment, (ii) assess the influence of building’s service life, energy, resource and waste management on the environmental performance of energy efficiency refurbishment, (iii) assess the influence of building size, design and location on the environmental performance of energy efficiency refurbishment, and (iv) to evaluate the contribution of energy efficiency refurbishment to New Zealand’s 2050 climate change mitigation target compared to the environmental performance of existing office building stock. The results showed that at energy efficiency refurbishments can reduce emissions for environmental impact categories affected by energy demand particularly for global warming, acidification and photochemical oxidation. However, the refurbishment is also associated with increase in environmental impacts affected by resource demand such ozone depletion potential, abiotic depletion of resources, human toxicity (carcinogenic) and ionizing radiation. Service life of over 25 years is required to compensate the embodied environmental impacts of refurbishment for most of the impact categories, particularly if the electricity is sourced from renewable energy sources. Refurbished components such as- on-site photovoltaic (PV), aluminium framed windows, façade components and heat pumps were identified as the major environmental hot-spots for most impact categories. The embodied environmental impacts to most categories could be reduced by 20 - 40 % if the waste recovery and recycling at construction site is improved. However, the overall environmental impacts of refurbished office buildings are highly sensitive to the choice of energy supply. Energy supply from grid electricity generated from renewable resources should be prioritised over the use of on- site PV. Benefits from on-site PV is limited if the grid electricity supply is mainly from renewable sources; moreover, the production of photovoltaic panels is energy and resource intensive. It can increase nearly 50 - 100 % of the embodied environmental associated with building refurbishment. If on- site photovoltaic is installed, it should be prioritised in buildings with large roof area located in regions with long sunshine hours. The results also show that in large buildings- efficient heating, ventilation and lighting equipment; and smaller wall to window ratios should be prioritised to reduce environmental impacts. In small buildings, the choice of façade materials with low embodied impacts should be prioritised to reduce environmental impacts. With respect to New Zealand’s 2050 target for the existing office building sector 60 - 90 % greenhouse gas emissions reductions is possible only if the office building stock refurbishment is combined with a renewable energy supply. Nearly 60 – 70 % of the greenhouse gas emissions can be reduced if the refurbishment of the existing office building stock is limited to existing large office building stock (>3500 m2) or to buildings in Auckland and Wellington. The main conclusions based on the results of this research are to prioritise better resource and waste management, to prioritise strategies for maintenance of refurbished buildings to promote longer service life, to support national level policies on increased use of renewable sources for grid electricity generation, and to prioritise refurbishment for a share of the building stock based on size and location which contributes to maximum energy reduction and minimal environmental impacts. The outcomes of this research can support national policy makers and independent building stakeholders (e.g. architects, owners, and engineers) who are keen on promoting energy efficiency refurbishments in New Zealand’s office buildings

NaturWall©: facciate in legno multifunzionali per la riqualificazione del patrimonio edilizio / NaturWall©:multifunctional wood façade in existent building refurbishment

Naturwall© is a research conducted by Politecnico of Turin (DAD) (under supervision of Prof.G.Callegari) and a local PMI support (Natural House, Castellamonte), promoted by Giovanni Goria Foundation "Master dei Talenti" programme. It consists in an innovative energy saving system by using wood multifunctional components for existent buildings . The goal of the project is the refurbishment of the existing building stock which were built from 1950's to 1980's. This stock is not equipped with recent energy requirements. The project aims to create a representative model of solution that will be promoted in Italy. In the field of renovation and refurbishment high energy results and greenhouse gases reduction could be achieved by using multifunctional facade system

Relationship between refurbishment project complexity and energy efficiency design performance through the mediating design team attributes / Siti Nor Azniza Ahmad Sekak

There is a rising concern about energy consumption in buildings and its possible adverse impacts on the environment. This situation has made the existing building owners and designers to integrate Energy Efficiency (EE) design features into their refurbishment projects. However, the complexities of the refurbishment projects and design team attributes have been argued to be the main factors that determine the EE design performance in the refurbishment projects. Therefore, the main aim of this research is to produce a framework of energy efficient design for refurbishment projects. The research objectives are (1) to identify the extent to which energy efficiency design performance measure incorporated in refurbishment projects, (2) to determine the complexity of refurbishment projects (3) to determine the design team attributes of refurbishment projects (4) to establish the extent to which design team attributes mediate the effects of project complexity on the energy efficiency design performance of refurbishment projects. The respondents for this research are Architects, Electrical Engineers, and Mechanical Engineers. The data collection started with a pilot research on twenty-three (23) respondents and followed by online final questionnaire survey that involved 510 respondents. The response rate of the online final questionnaire survey was 29.8 percent. Exploratory Factor Analysis (EFA) was conducted to validate and refine the data collected. The Statistical Package for Social Science (SPSS) and Relative Importance Index (RII) analysis was used in the data analysis for both descriptive and inferential statistics. The overall relationships of the conceptual framework were analysed by using structural equation modeling (SEM) based on the PLS approach. The research found that refurbishment projects are generally moderately complex. The top three factors that caused the complexity are, ‘matching of new material with the existing materials’, ‘the availability of energy efficient material databases’ and ‘integrating energy efficiency technology into the existing building’. The quality of the design team attributes and the energy efficiency design performance are also at moderate level. The findings also found that the design team attributes mediate the effect of refurbishment projects complexity on energy efficiency design performance. The research recommends the design team attributes, especially those related to Managerial Attributes should be improved in order to increase EE design performance of refurbishment projects

Relationship between refurbishment project complexity and energy efficiency design performance through the mediating design team attributes / Siti Nor Azniza Ahmad Sekak

There is a rising concern about energy consumption in buildings and its possible adverse impacts on the environment. This situation has made the existing building owners and designers to integrate Energy Efficiency (EE) design features into their refurbishment projects. However, the complexities of the refurbishment projects and design team attributes have been argued to be the main factors that determine the EE design performance in the refurbishment projects. Therefore, the main aim of this research is to produce a framework of energy efficient design for refurbishment projects. The research objectives are (1) to identify the extent to which energy efficiency design performance measure incorporated in refurbishment projects, (2) to determine the complexity of refurbishment projects (3) to determine the design team attributes of refurbishment projects (4) to establish the extent to which design team attributes mediate the effects of project complexity on the energy efficiency design performance of refurbishment projects. The respondents for this research are Architects, Electrical Engineers, and Mechanical Engineers. The data collection started with a pilot research on twenty-three (23) respondents and followed by online final questionnaire survey that involved 510 respondents. The response rate of the online [mal questionnaire survey was 29.8 percent. Exploratory Factor Analysis (EFA) was conducted to validate and refine the data collected. The Statistical Package for Social Science (SPSS) and Relative Importance Index (RII) analysis was used in the data analysis for both descriptive and inferential statistics. The overall relationships of the conceptual framework were analysed by using structural equation modeling (SEM) based on the PLS approach. The research found that refurbishment projects are generally moderately complex. The top three factors that caused the complexity are, 'matching of new material with the existing materials', 'the availability of energy efficient material databases' and 'integrating energy efficiency technology into the existing building'. The quality of the design team attributes and the energy efficiency design performance are also at moderate level. The findings also found that the design team attributes mediate the effect of refurbishment projects complexity on energy efficiency design performance. The research recommends the design team attributes, especially those related to Managerial Attributes should be improved in order to increase EE design performance of refurbishment projects

Using MCDA to select refurbishment solutions to improve buildings IEQ

Due to buildings high energy consumption their refurbishment is essential to achieve the targets defined by the EPBD-recast regarding energy efficiency and reduction of carbon emissions. Besides the energy efficiency, the sustainability and the Indoor Environmental Quality (IEQ) of Buildings must also be considered when planning a refurbishment project. Thus, to propose an effective building refurbishment it is necessary to select the adequate construction solutions taking into account their impact on the energy performance, thermal and acoustic comfort, indoor air quality and environmental impact of the building. In this work a multi-criteria decision analysis method is applied to balance all these aspects in a refurbishment project, in order to assist the design team on the selection of the construction solutions. Throughout the multi-criteria analysis performed, it was possible to verify that the rehabilitation solutions with lower embodied energy were the best refurbishment options

Sustainable refurbishment for an adaptable built environment

The reconsideration of the existing building stock is motivated by society’s efforts towards sustainability and resilience. The building sector has a considerable role to play in doing so. The process of refurbishment is complex, since aspects such as design decisions, existing construction, energy efficiency, and user behaviour need to be considered. The motivation for refurbishing existing buildings is related to environmental, social, and economic aspects of their use or reuse, which are the three core aspects of sustainability. The key environmental motivation is to reduce energy consumption from fossil fuels and related greenhouse gases (GHG) emissions, and to include energy generation from renewables; the key economic motivation is to lessen the cost of energy used for heating, and the key social motivation is to reduce fuel poverty and improve the quality of life and well-being of the occupants.This chapter aims to explain the role of refurbishment of the building stock for sustainability and resilience. Firstly, definitions of the levels of building upgrades are given, and the motivations for refurbishment are discussed. Furthermore, the ecological, economic, and social aspects of refurbishment are deliberated on, together with the importance of the building stock for resilience. Finally, case studies of refurbishment projects are presented, providing insights into different aspects of refurbishment for sustainability and resilience

Cost-effective analysis for selecting energy efficiency measures for refurbishment of residential buildings in Catalonia

© 2016. This version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper presents the results of a detailed method for developing cost-optimal studies for the energy refurbishment of residential buildings. The method takes part of an innovative approach: two-step evaluation considering thermal comfort, energy and economic criteria. The first step, the passive evaluation, was presented previously [1] and the results are used to develop the active evaluation, which is the focus of this paper. The active evaluation develops a cost-optimal analysis to compare a set of passive and active measures for the refurbishment of residential buildings. The cost-optimal methodology follows the European Directives and analysed the measures from the point of view of non-renewable primary energy consumption and the global costs over 30 years. The energy uses included in the study are heating, domestic hot water, cooling, lighting and appliances. In addition, the results have been represented following the energy labelling scale. The paper shows the results of a multi-family building built in the years 1990–2007 and located in Barcelona with two configurations: with natural ventilation and without natural ventilation. The method provides technical and economic information about the energy efficiency measures, with the objective to support the decision process.Postprint (author's final draft

Improving buildings refurbishment through operative conditions evaluation

As EU existing buildings stock account for 40% of the total energy consumption, it is important to take measures to reduce these needs and, consequently, reduce the EU external energy dependency as well as reducing the greenhouse gas emissions, in accordance with what is prescribed in the EU Directive 2002/91/EU on Energy Efficiency in Buildings (EPBD) and reinforced with the "EPBD-recast". The implementation of energy efficiency measures in the existing building stock is necessary to meet the 2020 targets. Thus, energy refurbishment of existing buildings is essential to achieve these goals. However, during the buildings refurbishment, energy issues should not be the only concerns since the indoor air quality is also as important. When planning a building refurbishment it is then necessary to take into account the energy efficiency exigencies and also the indoor air quality. To do so, the main problems of the existing buildings should be identified, in order to do the right choices regarding the refurbishment project. This work presents a study carried out in a large office building to identify the main pathologies, related to the energy efficiency and also to the indoor air quality. The study encompasses an “in-situ” evaluation of the operating conditions, indoor air quality and air change rate. The main objective of this study was to support the development of a refurbishment project of the building that can optimize the energy efficiency, but also the relevant parameters to the Indoor Air Quality. The results showed that the building has a poor envelope thermal resistance, inadequate shading systems and also several problems regarding high concentration of some pollutants like CO2 or VOC

Tracking the energy refurbishment processes in residential building stocks. The pilot case of Piedmont region.

The objective of the IEE-EPISCOPE project is to make the energy refurbishment processes in the European housing sector more transparent and effective. Each participating country is developing a pilot action, aiming at tracking the refurbishment progress of housing stocks at different scales. In the present article, the monitoring of the Piedmont regional housing stock is concerned. A preliminary analysis on data sources is performed, to identify the current state of the stock and the refurbishment rates. The results are a basis to carry out energy performance calculations and to assess future refurbishment scenarios and quantify the energy saving potentials

Energy efficiency refurbishment of UK owner-occupied homes: the householders’ perspective

Owner-occupiers represent 63.1% of UK households (ONS, 2016); a key group to focus attention on as a means to increase domestic energy efficiency rates (Risholt et al, 2013). The experiences of early-adopters of measures such as external wall insulation within this group may affect the future adoption rates, through word-of mouth referrals (McMichael & Shipworth, 2013). Householders’ are often willing to tolerate disruption, but unexpected delays or complications can cause considerable stress (Vadodaria et al., 2010). Negative attitudes can develop towards a refurbishment experience due to technological faults or internal disputes leading to problems with workmanship (Crosbie and Baker, 2010). These experiences can lead to dissatisfaction with the experience and potentially the refurbishment outcome in terms of energy demand and living environment comfort. This study has followed ten owner-occupied case study households through an energy efficiency refurbishment process. Householders’ were interviewed pre, during and post refurbishment over a period of one year, with a focus on the expectations and experiences of the refurbishment in terms of process and potential changes to thermal environment comfort and space heating energy demand. The interview data were triangulated with measurements of internal air temperature, air leakage tests and space heating energy use in addition to space heating energy modelling, using a version of the Standard Assessment Procedure (2009). The findings show that in terms of refurbishment process, measures which installers’ have more apparent experience in, such as combination boiler or window replacements have few unexpected events and outcomes, whereas measures such as external wall insulation and air leakage sealing can lead to refurbishment delays or dissatisfaction with workmanship. Two households exceeded the 2050 target for an 80% reduction in CO2 emissions from space heating. Nine improved thermal environment comfort levels, as supported by measurements. However the impact on householder perceptions of disruption and workmanship may affect future uptake. Policy and installer recommendations are made including the need for consistent policy and urgent improvements to installer customer service, energy efficiency expertise and skills