Identification of the Retrofit Actions to Achieve Cost-Optimal and NZEB Levels for Residential Buildings in Istanbul Considering the Remaining Building Lifetime

Cost-optimal and nearly-zero energy building (NZEB) levels are two interrelated concepts identified for upgrading energy performance of buildings in Europe. In parallel, many research activities on retrofitting existing buildings in Turkey follow the methodology framework introduced by the European Commission. However, in Turkey, there is a process called "urban transformation" due to the earthquake risk, but the practice is based on new construction after demolishment of existing buildings. Especially in Istanbul, this process has been conducted rapidly. This specific aspect requires assessment of cost-optimal retrofit analyses considering the remaining lifespan of analysed buildings. This study presents a cost-optimality assessment method for retrofitting towards NZEB in Turkey. The method integrates payback period and investment cost assessment to the methodology in order to obtain whole picture for retrofit alternatives. In the paper, suggested method is applied to a reference residential building in Istanbul. After the initial cost-optimal analyses, payback periods and initial investment costs for selected retrofit packages are assessed considering the future lifespan of the building. Together with these, possible subsidy opportunities are also investigated. Results show that, if the expected future lifespan is higher than 10 years, retrofit actions achieving 56.2kWh/m2y primary energy consumption level are considerable. Subsidies are beneficial to obtain reasonable initial investment costs

Identification of the Retrofit Actions to Achieve Cost-Optimal and NZEB Levels for Residential Buildings in Istanbul Considering the Remaining Building Lifetime

Cost-optimal and nearly-zero energy building (NZEB) levels are two interrelated concepts identified for upgrading energy performance of buildings in Europe. In parallel, many research activities on retrofitting existing buildings in Turkey follow the methodology framework introduced by the European Commission. However, in Turkey, there is a process called “urban transformation” due to the earthquake risk, but the practice is based on new construction after demolishment of existing buildings. Especially in Istanbul, this process has been conducted rapidly. This specific aspect requires assessment of cost-optimal retrofit analyses considering the remaining lifespan of analysed buildings. This study presents a cost-optimality assessment method for retrofitting towards NZEB in Turkey. The method integrates payback period and investment cost assessment to the methodology in order to obtain whole picture for retrofit alternatives. In the paper, suggested method is applied to a reference residential building in Istanbul. After the initial cost-optimal analyses, payback periods and initial investment costs for selected retrofit packages are assessed considering the future lifespan of the building. Together with these, possible subsidy opportunities are also investigated. Results show that, if the expected future lifespan is higher than 10 years, retrofit actions achieving 56.2kWh/m2y primary energy consumption level are considerable. Subsidies are beneficial to obtain reasonable initial investment costs

Effect of Economic Indicators on Cost-Optimal Energy Performance Levels of Residential Buildings Retrofits in the Mediterranean Region of Turkey

This study aims to analyse the effect of economic indicators on cost-optimal levels of residential building retrofits in Mediterranean region of Turkey. Sensitivity analyses were applied on the cost-optimality calculation results for the residential reference building. The sensitivity analyses address discount rate and potential investment cost decreases. Results reveal that 6% variation in the discount rate corresponds to more than 30 kWh/m2y difference in the primary energy consumption of the cost-optimal solutions. Potential investment cost decreases for certain retrofit measures are also effective on identified cost-optimal levels and subsidy opportunities appear as an effective tool to achieve higher energy efficiency in existing buildings and to stimulate building energy retrofits

THE SAMPLES OF ENERGY MODELLING FOR ENERGY EFFICIENT GREEN BUILDING DESIGN IN TURKEY

ABSTRACT The interest on voluntary green building certification systems is increasing in the last decade in Turkey. Thus the energy performance modeling and simulations are gradually taking part in the building design stages. The aim of the paper is to discuss the several real building examples of energy performance simulations in Turkey and so to lay out the effects of utilizing energy performance simulations on different levels of building design. The given examples generally discuss the problems of inefficient system designs, not setting sustainable design objectives on early design stages, building owners' special requierements and simulation tool restrictions

A comprehensive cost-optimal approach for energy retrofit of existing multi-family buildings: Application to apartment blocks in Turkey

This research presents a comprehensive cost-optimal approach for existing building retrofits. Theapproach incorporates energy efficiency measures related to building envelope, building energy systemsand renewable energy, all at once. Moreover, the cost-optimal calculation scope is extended throughintegration of occupant behaviour.The comprehensive approach is implemented for a reference building which represents high-rise apart-ment blocks in Turkey; these building types accommodate 4500 families corresponding to 23.1% ofthe national households. Three different climatic regions, that show significant distinction from eachother, were selected for the sample application of the approach in order to refer different climates. Cost-optimal calculations were performed for more than 1300 scenarios. Integration of occupant behaviourinto this calculation procedure was demonstrated with sensitivity analyses; the present application ofthe approach was focused on the use of window openings by occupants.Results reveal that cost-effective energy saving potential is higher than 70% in high-rise apartments.Moreover, occupant behaviour related to window openings is able to raise this rate above 80%. Thefindings indicate the necessity of comprehensive approach and demonstrate that integration of occupantbehaviour into cost-optimal calculations is fundamental in order to reach significant and stable results