Factsheet: Cost-effective Building Renovation at District Level Combining Energy Efficiency & Renewables (PDF 0.78MB) 
November 2019
Author(s): Annex 75
Buildings are a major source of greenhouse gas emissions and cost-effectively reducing their energy use and associated emissions is particularly challenging for the existing building stock, mainly because of the existence of many architectural and technical hurdles. The transformation of existing buildings into low-emission and low-energy buildings is particularly challenging in cities, where many buildings continue to rely too much on heat supply by fossil fuels. However, at the same time, there are specific opportunities to develop and take advantage of district-level solutions at urban scale. In this context, the project aims to clarify the cost-effectiveness of various approaches combining both energy efficiency measures and renewable energy measures at the district level. At this level, finding the balance between renewable energy measures and energy efficiency measures for the existing building stock is a complex task and many research questions still need to be answered.

Annex 75 Newsletter - September 2021 
September 2021

Comparative Analysis between Dynamic and Quasi-Steady-State Methods at an Urban Scale on a Social-Housing District in Venice 
August 2021
Author(s): Tiziano Dalla Mora, Lorenzo Teso, Laura Carnieletto, Angelo Zarrella, Piercarlo Romagnoni
The residential building stock represents one of the major players in energy use and greenhouse gas emissions; thus, it is fundamental to reduce the energy used. Simulation tools are becoming more and more accurate in compliance with the new requirements both at the single-building and at the district scale, although they are not affordable by non-specialist users such as policymakers. The research concerns the evaluation of the energy demand for space heating for a historical district that is representative of the Italian building stock. The work compares dynamic and specialist-oriented urban scale tools such as Energy Urban Resistance Capacitance Approach (EUReCA) and City Energy Analyst (CEA)) as well as a quasi-steady-state calculation method (Excel spreadsheet), which is more affordable for non-specialist users. The work was carried out to assess the possible deviation of the results between the dynamic and quasi-steady-state calculation methods, as well as to identify any limits and opportunities in the application of the latter procedure, which is currently the official national calculation tool for the implementation of Directive 2010/31/EU. The study shows how the quasi-steady-state method predicts a reliable building energy demand, in line with the results obtained by the two dynamic tools, when considering only geometry and infiltrations as input. However, the limits of the quasi-steady-state method emerge when introducing internal loads, significantly underestimating the energy demand compared to CEA and EUReCA simulations. The results underline the potential application of the quasi-steady-state method to predict energy demand, although dynamics tools are more reliable but far more complex. Major findings through two methods concern the impact of solar heat gains on the overall heating demand at both the single building and the district scale. The different results between the tools provided evidence of a gap in the use of the simplest tool and demonstrated the accuracy and reliability of the proposed approach with a lower computational effort.

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Building renovation at district level – Lessons learned from international case studies 
May 2021
Author(s): Jørgen Rose, Kirsten Engelund Thomsen, Silvia Domingo-Irigoyen, Roman Bolliger, David Venus, Thaleia Konstantinou, Erwin Mlecnik, Manuela Almeida, Ricardo Barbosa, Jon Terés-Zubiaga, Erik Johansson, Henrik Davidsson, Mira Conci, Tiziano Dalla Mora, Simone Ferrari, Federica Zagarella, Ana Sanchez Ostiz, Jorge San Miguel-Bellod, Aurora Monge-Barrio, Juan Maria Hidalgo-Betanzos

Neighbourhood consultancy centres for the adoption of low-carbon technologies by homeowners: experiences from Dutch initiatives (PDF 0.48MB) 
March 2021
Author(s): Erwin Mlecnik,Oubbol Oung, Ariane Lelieveld, Marianne de Snoo, Coen Vos

Annex 75 Newsletter - December 2020 
December 2020

Success Story in Switzerland - Weggis (PDF 1.21MB) 
December 2020
The document reports detailed information of a Sucess Story in Switzerland concerning neighbourhood renovation in Weggis

Success Story in Sweden - Hagalund (PDF 0.72MB) 
December 2020
The document reports detailed information of a Sucess Story in Sweden, concerning neighbourhood renovation in Hagalund

Cost-effective building renovation at district level combining energy efficiency & renewables 
Methodology assessment proposed in IEA-Annex 75 and a demonstration case study
October 2020
Author(s): Jon Terés-Zubiaga, Roman Bolliger, Manuela G. Almeida, Ricardo Barbosa, Jørgen Rose, Kirsten E. Thomsen, Eduardo Montero, Raúl Briones-Llorente
Building renovation plays a key role in reducing greenhouse gas emissions and achieving the climate pro-tection goals. The district scale approach is one of the most effective approaches to accelerate this processof reducing the energy consumption in the building sector as increasing its renovation rates. In this con-text, the Energy in Buildings and Communities Programme of the IEA, IEA-EBC started in 2017 the project‘‘Annex 75: Cost-Effective Building renovation at District Level Combining Energy Efficiency andRenewables” aiming to explore optimal opportunities of district renovations from a cost-benefit perspec-tive. IEA Annex 75 is a co-operative effort of participants from 13 different countries: Austria, Belgium,China, Czech Republic, Denmark, Germany, Italy, The Netherlands, Norway, Portugal, Spain, Swedenand Switzerland. In this paper, key elements of the methodology developed in Annex 75 project are pre-sented. This methodology aims to facilitate the identification of optimal solutions in different Europeancountries, enabling to explore similarities and differences amongst them, with a particular focus on thebalance between energy efficiency measures and renewable energy measures. After a detailed descrip-tion of the developed methodology, it is also applied to a case study located in Portugal and resultsobtained are analysed in detail. The paper demonstrates the usefulness of the methodology for evaluatingand identifying optimal solutions in renovations at district scale, as well as for successfully addressing theresearch questions investigated by the Annex 75 project. They also provide some insights regarding thespecific case study, showing that, although district systems are not usual in the current Portuguese con-text, these centralised solutions in renovations at district level are cost-effective interventions that canlead to significant reductions of greenhouse gas emissions and non-renewable primary energy use.

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Success Story in Portugal - Vila D´Este (PDF 5.5MB) 
May 2020
The document reports detailed information of a Sucess Story in Portugal, concerning neighbourhood renovation in Vila Nova de Gaia.

Success Story in Portugal - Rainha Dona Leonor (PDF 5.43MB) 
May 2020
The document reports detailed information of a Sucess Story in Portugal, concerning neighbourhood renovation in Porto.

Success Story in Portugal - Boavista (PDF 8.01MB) 
May 2020
The document reports detailed information of a Sucess Story in Portugal, concerning neighbourhood renovation in Lisboa.

Tecnology Overview Report (PDF 8.56MB) 
May 2020
Author(s): Ove C. Mørck, Jørgen Rose, Kirsten Engelund Thomsen, Tomas Matuska, Sergio Vega Sanchez
This report is the first of the deliverables from the IEA Annex 75 project. It documents the work of Subtask A – Technology Overview. As the title of the subtask indicates, the idea of this subtask was to create an overview of the available technologies for energy renovation and renewable energy supply at the district level.

The technical and economic characteristics of the technology options are also determined. This includes in particular information on their efficiency, cost elements such as investment costs and operational costs taking into account economies of scale. The interdependencies, obstacles and success factors for combining the technology options are also described.
The technology options are put into context with available potentials, and an outlook is made on their future developments.

Success Story in Spain - Vitoria-Gasteiz (PDF 1.34MB) 
March 2020
The document reports detailed information of a Success Story in Spain, concerning district renovation in Vitoria-Gasteiz

Success Story in Spain - Tudela (PDF 0.48MB) 
February 2020
The document reports detailed information of a Sucess Story in Spain, concerning district renovation in Tudela.

Success Story in Italy - Valdastico (PDF 0.55MB) 
February 2020
The document reports detailed information of a Sucess Story in Italy, concerning district renovation in Valdastico.

Success Story in Italy- Venice Campus (PDF 0.62MB) 
February 2020
The document reports detailed information of a Sucess Story in Italy, concerning district renovation in the Venice IUAV Campu

Success Story in Italy - Sangallo (PDF 1.05MB) 
February 2020
The document reports detailed information of a Sucess Story in Italy, concerning district renovation in Sangallo.

Success Story in Italy - Turin (PDF 0.47MB) 
February 2020
The document reports detailed information of a Sucess Story in Italy, concerning district renovation in Turin.

Success Story in Austria - Strubergrasse (PDF 0.8MB) 
February 2020
The document reports detailed information of a Sucess Story in Austria, concerning district renovation in Strubergrasse.

Success Story in Italy - Modena (PDF 0.69MB) 
February 2020
The document reports detailed information of a Sucess Story in Italy, concerning district renovation in Modena.

Success Story in Denmark - Aalborg (PDF 1.02MB) 
February 2020
The document reports detailed information of a Sucess Story in Denmark, concerning district renovation in Aalborg

Potential of building renovation at district level for reducing CO2 emissions and fostering urban regeneration. IEA-EBC Annex 75 (PDF 0.56MB) 
October 2019
Author(s): Jon Terés-Zubiaga, Manuela G. Almeida , Ove Mørck, Roman Bolliger, David Venus
Publisher: Proceedings of 10th EUROPEAN CONFERENCE ON ENERGY EFFICIENCY AND SUSTAINABILITY IN ARCHITECTURE AND PLANNING, VITORIA-GASTEIZ, 2019

Workshop on upscaling energy renovation to the district level - Summary and Main Findings (PDF 1.56MB) 
Delft, September, 25th, 2019
September 2019
Author(s): Erwin Mlecnik and Thaleia Konstantinou

Workshop on district renovation towards nZEB - Summary and Main Findings (PDF 0.57MB) 
Bilbao, March 27th, 2019
June 2019
Author(s): Juan María Hidalgo-Betanzos

Success Story in Sweden - Lund (PDF 1.27MB) 
May 2019
The document reports detailed information of a Sucess Story in Sweden, concerning district renovation in Lund.

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ASHRAE Energy Efficiency for Existing Buildings Standard 100 (PDF 4.72MB) 
Deep Energy Retrofit of Buildings Forum 2016 - Washington DC
September 2016
Author(s): Wayne Stoppelmoor

Annex 75 Newsletter - March 2020 

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Annex 75 Newsletter - July 2019 

Annex 75 Newsletter-November 2018 

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O potencial das intervenções de renovação a nível urbano para edifícios nZEB (PDF 0.5MB) 
Portuguese national journal article
Author(s): Manuela Almeida and Ricardo Barbosa
Publisher: Edifícios e Energia