Thermal & Environmental Performance Implications of new vs Thermal & Environmental Performance Implications of new vs. retrofitted buildings: A case study Thommy James PADAYHAG, Ulrich PONT, Ardeshir MAHDAVI ulrich.pont@tuwien.ac.at Department of Building Physics and Building Ecology, TU Wien, Vienna, Austria

Table of Content Introduction Methodology Results & Discussion Overview & Research Question Related Work Methodology Buildings Scenarios Tools & Indicators Results & Discussion Conclusion

Introduction Overview Buildings contribute to…. {you all know} CO2-Emissions / Energy Use – Ambitious goals 2020 Thermal retrofit rate of 3% would be required in Austria Building Stock versus new buildings Tightening requirements Case Study: Houses in Burgenland (Province in Austria) Country side problems “Development issues” Abandoned places Young families  search for places to life

Introduction Research question: Related Work General comparison between different scenarios (retrofit and new construction) How does an existing, yet to be adapted and retrofitted building perform in comparison to a complete new one? Thermal performance ? Ecological footprint? Energy efficiency? Investment cost implications? Related Work Korytaorva & Urge-Vorsatz: public buildings in Hungary Switzerland: replacement of old residential buildings? Fraunhofer (early!): anyhow – insulation is required…

Methodology Buildings: Location: Unterwart, Burgenland Old building (1950) 119 m² usable area (30 m² gross area) Partly agricultural use Traditional construction (bricks, casement windows, non- insulated roof))

Methodology Buildings: House 1950

Methodology Buildings: House 2014

Methodology Buildings: House 1950+

Methodology Scenarios 6 different

Methodology Scenarios Conventions regarding input information

Methodology Scenarios Conventions regarding input information

Methodology Scenarios Key Data

Methodology Tools Thermal Simulation (Energy Plus)  Heating Demand, Overheating Normative Procedures (Archiphysik)  Heating Demand OI3-Method (in Archiphysik) for Eco-Footprint Sktech-Up for Modelling Literature (sirados – Cost-Indicator-Books) for Cost

Results & Discussion Results

Results & Discussion Results Strengths and weaknesses of all scenarios S1  lowest overall cost, heating demand & CO2-emissions are highest S2.1.  (absolute) lowest heating demand, rather low cost S4  lowest heating demand / m², highest cost, worst OI3- points S3.2, S2.2. increase heated volume, but not liveable space  Not recommendable

Conclusion Bright and bad sides of different scenarios Effort of new construction by far largest Aspect of suitability of chosen scenario for client “Assumptions” User behaviour Good architect / planner required for each scenario Comprehensive and thoughtful planning required in any case Decision  not easy to decide (Optimization problem) Viewpoint of “sustainability”: Reuse of existing structures desirable.

!Thank you for your attention! Thermal & Environmental Performance Implications of new vs. retrofitted buildings: A case study Thommy James PADAYHAG, Ulrich PONT, Ardeshir MAHDAVI ulrich.pont@tuwien.ac.at Department of Building Physics and Building Ecology, TU Wien, Vienna, Austria