Residential Building Stock of Tbilisi City
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Public Disclosure Authorized Public Disclosure Authorized Public Disclosure Authorized Public Disclosure Authorized Executive Summary For most commercial and residential buildings, energy is one of the largest operating expenses over a building’s useful life. Energy consumption (and costs associated with such consumption) can be minimized through proactive, technical approaches during building design, construction, operations, and through retrofitting, when possible. Yet the historic and current construction market in Georgia rarely delivers buildings designed for energy efficient operations, and the energy performance of the building stock so far remains a challenge. With increased urbanization, energy consumption in the residential sector will continue to increase in the near future. Electricity consumption in the housing sector globally has doubled between 1980 and 2000 and is expected to increase by another 50% by 2025 (EIA 2005a.) New buildings are added to the national building stock faster than old buildings are retired. As part of the Association Agreement with the EU, Georgia has committed to improve energy efficiency (EE) in its housing stock, increase the country’s use of renewable energy sources, and reduce its greenhouse gas emissions. This initiative has already led to significant changes in the country’s construction sector. NIRAS engineering consultancy company, Environment and School Initiatives (ENSI) and Sustainable Development and Policy Center (SDAP) consortium, with the support from the Danish International Development Agency (DANIDA), worked closely with the Government and developed the regulations on minimum energy performance requirements for the buildings. In recent years, several projects addressing energy efficiency have been completed in Georgia, including the European Commission-funded project on Retrofitting Three Kindergartens in Rustavi and the Nordic Environment Finance Corporation financed project on Energy Efficiency Rehabilitation of 25 Public Buildings nationwide. The objectives of this report are to improve Tbilisi Municipality’s and its district units’ technical capacity in energy efficiency retrofits of housing stock and offer a set of standards and guidelines for such retrofits. This report offers a comprehensive approach for promoting energy efficiency, and includes a discussion of the regulatory and legislative framework, provides an overview of residential building stock of Tbilisi, offers energy modeling results, and proposes standards and technical solutions (including detailed engineering design and bill of quantities for the selected apartment building). The structure of this document is: 1. Chapter 1 describes the energy efficiency legislative framework applicable to the construction sector in Georgia. 2. Chapter 2 summarizes experts’ analysis on residential structure, composition and energy consumption of residential building stock of Tbilisi City. 3. Chapter 3 provides an analysis of energy modeling of reference dwelling with an assessment of energy-saving potential and identification of energy efficiency measures for the selected focus group of 8-floor dwellings. 4. Chapter 4 presents guidelines of technical solutions and recommendations for energy efficiency retrofit designs for dwellings, to enable local governments to implement energy efficiency retrofit projects. 5. Annexes cover the energy audit and the proposed intervention measures for the selected residential building, supported with the technical documentation package. - 1 - Acknowledgments This report was prepared by a team of the World Bank experts comprising Dr. Karine Melikidze, Dr. Valerian Melikidze, Giorgi Lekveishvili, Boris Dgebuadze, Genadi Makharadze, Giorgi Shengelia and Zurab Tsikhiseli, under supervision and guidance of Tengiz Gogotishvili. The report benefited from insightful comments and valuable support provided by Osman Masood. The team extends its appreciation to the Tbilisi Mayor’s Office and it’s Infastructure Department team including Irina Cheishvili, Irakli Darakhvelidze and David Doghonadze for the excellent collaboration and support provided in the process. The financial and technical support by the Energy Sector Management Assistance Program (ESMAP) is gratefully acknowledged. ESMAP - a global knowledge and technical assistance program administered by the World Bank - assists low- and middle-income countries to increase their know-how and institutional capacity to achieve environmentally sustainable energy solutions for poverty reduction and economic growth. ESMAP is funded by Australia, Austria, Canada, ClimateWorks Foundation, Denmark, the European Commission, Finland, France, Germany, Iceland, Italy, Japan, Lithuania, Luxembourg, the Netherlands, Norway, the Rockefeller Foundation, Sweden, Switzerland, the United Kingdom, and the World Bank. - 2 - Contents Executive Summary ............................................................................................................................ 1 Acknowledgments .............................................................................................................................. 2 Abbreviations ..................................................................................................................................... 5 Introduction ....................................................................................................................................... 6 Legislative framework of the construction sector of Georgia ............................................................7 Residential Building Stock of Tbilisi City - Composition, Structure and Energy Consumption ...........................................................................11 Outlook of the Energy Saving Potential for the Energy Efficiency Retrofit of the Residential Building Stock in Tbilisi ...........................................................................22 Guidelines: Technical Solutions & Recommendations for the Energy Efficiency Retrofitting Designs ..................................................................................30 Case Studies and Lessons Learned from Other Countries ................................................................37 Conclusion ........................................................................................................................................ 43 References ........................................................................................................................................ 45 Annex 1: Energy Assessment Report of the Selected Residential Multi-Apartment Building ...................................................................46 Annex 2: Detailed Design for the Energy Efficiency Rehabilitation of the Selected Residential Building .................................................................................. 55 - 3 - List of Figures Figure 1: Map of Georgia with designated climate zones .....................................................10 Figure 2: Dwellings by the year of construction completion .................................................11 Figure 3: A 5-floor apartment building from 1960s, the first wave of the “Khrushchev” housing program ....................................................................... 13 Figure 4: Layout of the typical floor of the “Khrushchev” type design series residential building ...................................................................................... 13 Figure 5: Building passport of the 5-floor residential building ..............................................14 Figure 6: An 8-floor apartment building from 1966, the second stage of the “Khrushchev” housing mass construction program. ........................................15 Figure 7: A 14-floor residential building (designed by architect Tukhareli) ...........................16 Figure 8: Building passport - facade of the type design for the 14-floor building .................17 Figure 9: Building passport - floor layout of the 14-floor apartment building ......................18 Figure 10: Breakdown of the building stock of Georgia by sub-categories .............................20 Figure 11: Changes of thermal transmittance coefficients for exterior walls in Georgia and other countries ............................................................................... 20 Figure 12: Distribution of dwellings by heated area in urban and rural areas of Georgia ......21 Figure 13: Layout of a typical floor for a typical 8-floor multi-apartment block-section unit ........................................................................ 23 Figure 14: Sections of the selected multi-apartment dwelling with 3 blocks ..........................24 Figure 15: Annual energy consumption computed by the ENSI software ...............................26 List of Tables Table 1: Calculation results of three climate zones for Georgia with HDD and CDD benchmarks and population per zone. ....................................10 Table 2: Minimum Energy performance requirements for the exterior building components .......................................................................... 10 Table 3: Composition of the residential building stock in Tbilisi distributed by subcategories .................................................................... 11 Table 4: Completed apartment buildings in Tbilisi in 2014-2018 .........................................19 Table 5: Energy consumption by the residential stock in Tbilisi ..........................................20