The SPSS data file consists of survey data from the X-tendo project on the end-user needs and exp... more The SPSS data file consists of survey data from the X-tendo project on the end-user needs and expectations from next-generation energy performance certificates.
The work reported herein is as a result of my own investigation, except where acknowledged and re... more The work reported herein is as a result of my own investigation, except where acknowledged and referenced. ………………………….
With the upsurge in the energy demand in Europe, the challenge to improve the existing building s... more With the upsurge in the energy demand in Europe, the challenge to improve the existing building stock's energetic performance calls out for a district and building level intervention through retrofitting measures. Often the amount and type of data required for the retrofit interventions are unclear, and it leaves the decision-makers in a dilemma within the development of low to high quality models based on its value as perceived by stakeholders. There exists a lack of robust indicators that could guide the EU member states to channelise their resources in reducing energy consumption based on the input data for simulation at district and building level. In this paper a QFD (Quality Function Deployment) model is developed to study the relationships between the stakeholder interests as outputs and different input datatypes and requirements, based on the level of detail, for simulation (physical, operational, environmental, geometrical and contextual data) that could impact the optimal model development. Keeping in mind the inadequacy of coherent computational models and informing the users about the implications of acquiring different data, here, the input datatypes, their interaction and collection are simplified to a greater extent through the proposed approach.
The authors would like to acknowledge the support of Science Foundation Ireland through the Caree... more The authors would like to acknowledge the support of Science Foundation Ireland through the Career Development Award programme (Grant No. 13/CDA/2200).
There are international activities and on-going initiatives, particularly at the European level, ... more There are international activities and on-going initiatives, particularly at the European level, to define what Positive Energy Districts should be, as the driving concept for the urban transition to a sustainable future. The first objective of the paper is to contribute to the on-going and lively debate about the definition of the notion of Sustainable Plus Energy Neighbourhood (SPEN), which highlights the multiple dimensions when talking about sustainability in districts moving beyond the traditional and strict building energy assessment. Based on a holistic methodology which ensures the consideration of the multidimensional nature and goals of SPEN, the paper outlines an evaluation framework. The evaluation framework defines the key performance indicators distributed in five categories that consider energy and power performance, GHG emissions, indoor environmental quality, smartness, flexibility, life cycle costs and social sustainability. This framework is designed to be impleme...
There is a dearth of data and evidence in the literature to assist the industry in determining th... more There is a dearth of data and evidence in the literature to assist the industry in determining the most appropriate strategies for large-scale deep retrofitting of non-domestic buildings to achieve healthy low-energy buildings. Support to decision-making and enabling deep retrofit of these buildings requires approaches such as long-term renovation strategies and building renovation passports. This paper compares the impact of single-step and staged retrofit approaches to improve the building energy performance of an existing building to a nearly zero-energy building (nZEB) level with improved comfort and optimal life-cycle costs. The novel developed methodological framework is applied to a university building built in 1975 (partially retrofit in 2005) that is expected to be completely retrofitted in 2020. A set of scenarios are analysed for the case study building using a combination of retrofit measures towards achieving the cost-optimal non-dominated solutions (Pareto front) based on multiple-objective optimisation for the decision-maker. The results highlight that a single-step retrofit can achieve a reduction of up to 60% in primary energy consumption and reduction of 38% in discomfort hours. The findings also indicate that nZEB performance with the primary energy consumption in the range of ~ 75–90 kWh m−2 year−1 (with plug loads) can be achieved cost-effectively through single-step deep retrofit for a university building. Results also highlighted the inability to achieve higher energy performance or improved comfort in two stages relative to completing a deep retrofit in a single stage. The results aim to contribute to the existing debate on the economic and environmental feasibility in realising long-term renovation strategies for existing non-domestic buildings, especially university buildings.
Deep-retrofit planning for existing buildings demands high accuracy in energy modelling predictio... more Deep-retrofit planning for existing buildings demands high accuracy in energy modelling prediction that minimises the gap between actual and simulated scenarios. A large set of interacting variables and uncertainties in energy performance modelling causes perturbations that can be minimised via model calibration. In this work, a novel multi-stage automated calibration methodology was developed using a case study of a partially-retrofitted university building (> 35 yrs old) in Ireland. The methodology enables the analysis of models for Indoor Environmental Quality (IEQ) variables along with energy demand. Due to the higher number of uncertainties in the model, a sensitivity analysis was conducted on the model that is both calibrated and validated as per ASHRAE Guide 14 indices of Cv(RMSE) and NMBE. The calibration process was automated using the optimisation algorithm NSGA-II with two sets of reference data i.e. monthly utility and hourly indoor air temperature. Results demonstrate that using only utility data for calibration did not result in accurate predictions of the thermal environment; thus, a second stage was used to improve the model prediction giving a Cv (RMSE) hourly = 17.0-25.5% and NMBE hourly = 3.6-10.0% for indoor air temperature across multiple zones. This paper demonstrates an effective staged approach for creating calibrated models of old buildings under high uncertainty that can be used to influence large-scale decision making for retrofits focused on improving indoor environment quality and energy performance.
Achieving standards-based Indoor Environmental Quality (IEQ) in existing buildings is growing ste... more Achieving standards-based Indoor Environmental Quality (IEQ) in existing buildings is growing steadily due to the strong demand for deep retrofits in Europe. Existing non-domestic buildings pose challenges mainly due to occupancy patterns, lack of personal control over comfort and outdated building structures. Renovations of many postwar non-domestic buildings (>35 years old) have faced technical and financial challenges. Consequently, these buildings are often only partially retrofitted, which are often ad-hoc in nature. This paper describes the evaluation process of indoor environmental conditions in a partially-retrofitted university building in Galway (Ireland) originally built during the 1970s and partially retrofit in 2005. The research assesses criteria outlined in EN 15251 and draws on methods from ASHRAE 55 and CBE IEQ survey. Occupant surveys complemented by physical measurements were used to assess the compliance of IEQ parameters for thermal, visual and acoustic comfort and indoor air quality. The relationship between the performance of the building envelope and occupant comfort is described across retrofitted and non-retrofitted zones of the building. The results suggest that ad-hoc retrofitting of the façade did not make any significant difference to IEQ and occupants continued to adapt personally to the existing conditions. Their preferred satisfaction levels in the survey were lower than the measured thermal sensation. It is recommended that future retrofits are adequately planned and optimised to improve both IEQ and energy performance. A whole building retrofit approach must balance and include factors such as human health, building fabric and energy savings to avoid the pitfalls of current practice.
The current rate of refurbishment in Europe is around 1%. On the other hand, refurbishment is a m... more The current rate of refurbishment in Europe is around 1%. On the other hand, refurbishment is a major focus on achieving energy targets by the member states. Thus, the rate of retrofitting will need to double or triple to help Europe meets its energy consumption reduction targets. A major share of the building stock in Europe is older than 50 years and about 40% of the existing residential buildings were constructed before 1960s when the building regulations for energy consumption of buildings were limited (BPIE 2011). Article 9 of the Energy Performance of Buildings Directive (EPBD) suggests that Member States must develop policies and measures to stimulate the transformation of buildings that are refurbished into nearly zero-energy buildings (nZEB) (EU 2010). The envelope targets are mentioned in the multi-annual roadmap under HORIZON 2020 by European Commission with due concern towards a reliable multi-objective envelope optimisation methodology that converges integration of all envelope constraints for new and refurbished buildings (EC 2013). Façade retrofit is identified as an intervention in the building envelope through addition, replacement or substitution of new or modernised materials, systems or components to an existing building. Façade retrofits are a critical part of deep retrofits where deep retrofits require 68% average depth of refurbishment indicating a proportion of energy savings achieved in the refurbishment (BPIE 2011). Façade retrofits were generally done in the past to fix specific problems or upgrade their appearance. The current retrofit scenario typically involves retrofitting of façade with the focus of achieving energy efficiency more than 50% (Hart et al. 2013). The performance targets are fundamentally derived based on the average U-values across Europe. However, this approach does not include other performance parameters that guide holistic retrofits. The role of façades cannot be ignored with respect to their importance towards social, economic and technical domains from a life cycle perspective (Sanguinetti 2012). There are limited studies and consensus on the concepts of
International Journal of Building Pathology and Adaptation, 2017
Purpose There is profound demand for higher skills and expertise in retrofitting the existing bui... more Purpose There is profound demand for higher skills and expertise in retrofitting the existing building stock of Europe. The delivery of low- or nearly zero-energy retrofits is highly dependent on technical expertise, adoption of new materials, methods of construction and innovative technologies. Future Irish national building regulations will adopt the Energy Performance of Buildings Directive vision of retrofitting existing buildings to higher energy efficiency standards. Construction industry stakeholders are key for the achievement of energy performance targets. Specifically, the purpose of this paper is to assess the attitudes, approaches and experiences of Irish construction professionals regarding energy efficient buildings, particularly nearly zero-energy buildings (nZEBs). Design/methodology/approach Data were collected through a series of quantitative and qualitative methods, including a survey, a workshop and detailed interviews with professionals in the retrofit industry....
The SPSS data file consists of survey data from the X-tendo project on the end-user needs and exp... more The SPSS data file consists of survey data from the X-tendo project on the end-user needs and expectations from next-generation energy performance certificates.
The work reported herein is as a result of my own investigation, except where acknowledged and re... more The work reported herein is as a result of my own investigation, except where acknowledged and referenced. ………………………….
With the upsurge in the energy demand in Europe, the challenge to improve the existing building s... more With the upsurge in the energy demand in Europe, the challenge to improve the existing building stock's energetic performance calls out for a district and building level intervention through retrofitting measures. Often the amount and type of data required for the retrofit interventions are unclear, and it leaves the decision-makers in a dilemma within the development of low to high quality models based on its value as perceived by stakeholders. There exists a lack of robust indicators that could guide the EU member states to channelise their resources in reducing energy consumption based on the input data for simulation at district and building level. In this paper a QFD (Quality Function Deployment) model is developed to study the relationships between the stakeholder interests as outputs and different input datatypes and requirements, based on the level of detail, for simulation (physical, operational, environmental, geometrical and contextual data) that could impact the optimal model development. Keeping in mind the inadequacy of coherent computational models and informing the users about the implications of acquiring different data, here, the input datatypes, their interaction and collection are simplified to a greater extent through the proposed approach.
The authors would like to acknowledge the support of Science Foundation Ireland through the Caree... more The authors would like to acknowledge the support of Science Foundation Ireland through the Career Development Award programme (Grant No. 13/CDA/2200).
There are international activities and on-going initiatives, particularly at the European level, ... more There are international activities and on-going initiatives, particularly at the European level, to define what Positive Energy Districts should be, as the driving concept for the urban transition to a sustainable future. The first objective of the paper is to contribute to the on-going and lively debate about the definition of the notion of Sustainable Plus Energy Neighbourhood (SPEN), which highlights the multiple dimensions when talking about sustainability in districts moving beyond the traditional and strict building energy assessment. Based on a holistic methodology which ensures the consideration of the multidimensional nature and goals of SPEN, the paper outlines an evaluation framework. The evaluation framework defines the key performance indicators distributed in five categories that consider energy and power performance, GHG emissions, indoor environmental quality, smartness, flexibility, life cycle costs and social sustainability. This framework is designed to be impleme...
There is a dearth of data and evidence in the literature to assist the industry in determining th... more There is a dearth of data and evidence in the literature to assist the industry in determining the most appropriate strategies for large-scale deep retrofitting of non-domestic buildings to achieve healthy low-energy buildings. Support to decision-making and enabling deep retrofit of these buildings requires approaches such as long-term renovation strategies and building renovation passports. This paper compares the impact of single-step and staged retrofit approaches to improve the building energy performance of an existing building to a nearly zero-energy building (nZEB) level with improved comfort and optimal life-cycle costs. The novel developed methodological framework is applied to a university building built in 1975 (partially retrofit in 2005) that is expected to be completely retrofitted in 2020. A set of scenarios are analysed for the case study building using a combination of retrofit measures towards achieving the cost-optimal non-dominated solutions (Pareto front) based on multiple-objective optimisation for the decision-maker. The results highlight that a single-step retrofit can achieve a reduction of up to 60% in primary energy consumption and reduction of 38% in discomfort hours. The findings also indicate that nZEB performance with the primary energy consumption in the range of ~ 75–90 kWh m−2 year−1 (with plug loads) can be achieved cost-effectively through single-step deep retrofit for a university building. Results also highlighted the inability to achieve higher energy performance or improved comfort in two stages relative to completing a deep retrofit in a single stage. The results aim to contribute to the existing debate on the economic and environmental feasibility in realising long-term renovation strategies for existing non-domestic buildings, especially university buildings.
Deep-retrofit planning for existing buildings demands high accuracy in energy modelling predictio... more Deep-retrofit planning for existing buildings demands high accuracy in energy modelling prediction that minimises the gap between actual and simulated scenarios. A large set of interacting variables and uncertainties in energy performance modelling causes perturbations that can be minimised via model calibration. In this work, a novel multi-stage automated calibration methodology was developed using a case study of a partially-retrofitted university building (> 35 yrs old) in Ireland. The methodology enables the analysis of models for Indoor Environmental Quality (IEQ) variables along with energy demand. Due to the higher number of uncertainties in the model, a sensitivity analysis was conducted on the model that is both calibrated and validated as per ASHRAE Guide 14 indices of Cv(RMSE) and NMBE. The calibration process was automated using the optimisation algorithm NSGA-II with two sets of reference data i.e. monthly utility and hourly indoor air temperature. Results demonstrate that using only utility data for calibration did not result in accurate predictions of the thermal environment; thus, a second stage was used to improve the model prediction giving a Cv (RMSE) hourly = 17.0-25.5% and NMBE hourly = 3.6-10.0% for indoor air temperature across multiple zones. This paper demonstrates an effective staged approach for creating calibrated models of old buildings under high uncertainty that can be used to influence large-scale decision making for retrofits focused on improving indoor environment quality and energy performance.
Achieving standards-based Indoor Environmental Quality (IEQ) in existing buildings is growing ste... more Achieving standards-based Indoor Environmental Quality (IEQ) in existing buildings is growing steadily due to the strong demand for deep retrofits in Europe. Existing non-domestic buildings pose challenges mainly due to occupancy patterns, lack of personal control over comfort and outdated building structures. Renovations of many postwar non-domestic buildings (>35 years old) have faced technical and financial challenges. Consequently, these buildings are often only partially retrofitted, which are often ad-hoc in nature. This paper describes the evaluation process of indoor environmental conditions in a partially-retrofitted university building in Galway (Ireland) originally built during the 1970s and partially retrofit in 2005. The research assesses criteria outlined in EN 15251 and draws on methods from ASHRAE 55 and CBE IEQ survey. Occupant surveys complemented by physical measurements were used to assess the compliance of IEQ parameters for thermal, visual and acoustic comfort and indoor air quality. The relationship between the performance of the building envelope and occupant comfort is described across retrofitted and non-retrofitted zones of the building. The results suggest that ad-hoc retrofitting of the façade did not make any significant difference to IEQ and occupants continued to adapt personally to the existing conditions. Their preferred satisfaction levels in the survey were lower than the measured thermal sensation. It is recommended that future retrofits are adequately planned and optimised to improve both IEQ and energy performance. A whole building retrofit approach must balance and include factors such as human health, building fabric and energy savings to avoid the pitfalls of current practice.
The current rate of refurbishment in Europe is around 1%. On the other hand, refurbishment is a m... more The current rate of refurbishment in Europe is around 1%. On the other hand, refurbishment is a major focus on achieving energy targets by the member states. Thus, the rate of retrofitting will need to double or triple to help Europe meets its energy consumption reduction targets. A major share of the building stock in Europe is older than 50 years and about 40% of the existing residential buildings were constructed before 1960s when the building regulations for energy consumption of buildings were limited (BPIE 2011). Article 9 of the Energy Performance of Buildings Directive (EPBD) suggests that Member States must develop policies and measures to stimulate the transformation of buildings that are refurbished into nearly zero-energy buildings (nZEB) (EU 2010). The envelope targets are mentioned in the multi-annual roadmap under HORIZON 2020 by European Commission with due concern towards a reliable multi-objective envelope optimisation methodology that converges integration of all envelope constraints for new and refurbished buildings (EC 2013). Façade retrofit is identified as an intervention in the building envelope through addition, replacement or substitution of new or modernised materials, systems or components to an existing building. Façade retrofits are a critical part of deep retrofits where deep retrofits require 68% average depth of refurbishment indicating a proportion of energy savings achieved in the refurbishment (BPIE 2011). Façade retrofits were generally done in the past to fix specific problems or upgrade their appearance. The current retrofit scenario typically involves retrofitting of façade with the focus of achieving energy efficiency more than 50% (Hart et al. 2013). The performance targets are fundamentally derived based on the average U-values across Europe. However, this approach does not include other performance parameters that guide holistic retrofits. The role of façades cannot be ignored with respect to their importance towards social, economic and technical domains from a life cycle perspective (Sanguinetti 2012). There are limited studies and consensus on the concepts of
International Journal of Building Pathology and Adaptation, 2017
Purpose There is profound demand for higher skills and expertise in retrofitting the existing bui... more Purpose There is profound demand for higher skills and expertise in retrofitting the existing building stock of Europe. The delivery of low- or nearly zero-energy retrofits is highly dependent on technical expertise, adoption of new materials, methods of construction and innovative technologies. Future Irish national building regulations will adopt the Energy Performance of Buildings Directive vision of retrofitting existing buildings to higher energy efficiency standards. Construction industry stakeholders are key for the achievement of energy performance targets. Specifically, the purpose of this paper is to assess the attitudes, approaches and experiences of Irish construction professionals regarding energy efficient buildings, particularly nearly zero-energy buildings (nZEBs). Design/methodology/approach Data were collected through a series of quantitative and qualitative methods, including a survey, a workshop and detailed interviews with professionals in the retrofit industry....
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Papers by Sheikh Zuhaib