What Americas Cup and a heritage building have in common They both aim at innovative technologies and cutting-edge solutions. The owner of the project, an ex-crew member of the most famous sailing match race in the world, pushed the planning team to develop extraordinary solutions for his house. The house, Villa Castelli, is an historical listed building located on the Como lake. During its history, it has been transformed many times, giving as results a non-uniform structure composed by different construction technologies. The aims of the owner were: an overall refurbishment particularly focused on energy efficiency, the exploitation of renewable energy sources based on-site production and a fixed budget. To reach these goals, the energy needs have been reduced improving the performance of the thermal envelope. Then, the building’s technical systems have been re-developed in order to exploit as much as possible available renewable energy sources. From the very beginning, it was clear that, for finding optimal solutions, a multidisciplinary approach was necessary. The design approach should be the result of a shared approach integrating different fields, such as creative design, technology, knowledge of material properties, building physics. The great synergy among building envelope retrofitting, innovative technological solutions and the deployment of renewable energy sources allows the transformation of this historical listed building into an outstanding example of a nearly zero energy building (nZEB).

Research and development of high thermal insulation materials for the construction sector requires an accurate characterization of the wall's performance, since that is the main causes of thermal exchanges between the internal and external boundaries. This paper presents a test procedure developed within the EU Project EFFESUS for evaluating the steady-state thermal performance of a masonry wall. A large-scale mock-up of the inhomogeneous wall was tested in a guarded hot box (GHB) apparatus before and after the application of an aerogel-based material. The methodology proposed in this paper is structured in the following steps: (i) definition of the wall geometry and the percentage of stone and mortar, using walls’ photographic records and geometrical surveys; (ii) precise thermal characterization of the material used; (iii) hygrothermal assessment procedure based on infrared technology (IRT) survey, gravimetric test, and monitoring of the internal relative humidity (RH); (iv) steady-state and dynamic thermal simulation; and (v) detailed set-up of the test using the data retrieved from the thermal surveys and simulations. According to the results of IRT surveys and the dynamic simulations, the mock-up was divided into thermal homogeneous parts, verifying the uniformity of the surface temperature and the heat flux in an isothermal area. This approach was validated both for low and high energy performance walls. Results show that the thermal flux was reduced to one third after the application of the aerogel.

Research and development of cost-effective, high-performance thermal insulation materials for the construction sector has to be focused on their final application. In particular, solutions for refurbishing historic buildings, which represent 40% of the European building stock, have to offer a good compromise between environmental quality, energy efficiency and conservation aspects. In this paper, the experimental assessment of an insulation material based on aerogel technology, recently developed in the European project EFFESUS, is presented with regard to the material's thermal performance, compatibility with historic fabric and reversibility. The overall results obtained in laboratory testing on a real-size mock-up and in a real-world case application indicate that the new material is a promising solution for retrofitting historic buildings, thanks to its thermal properties, easy application, reversibility and material compatibility.

When deciding on the best historic building retrofit, energy savings and thermal comfort can be quantitatively evaluated using an energy model, whereas conservation compatibility is intrinsically qualitative and reflects the perspective of the local heritage authority. We present a methodology that permits finding and comparing optimal retrofits for historic buildings in a multi-perspective and quantitative way. We use an analytic hierarchy process to quantify conservation compatibility by distilling a conservation score from the opinions of 10 experts in the field. This score, along with energy needs for heating and cooling and thermal comfort, are the three targets of a multi-objective optimization aimed at identifying optimal retrofits for a medieval building in the north of Italy, destined to become a museum. Retrofit measures considered were different kinds of external and internal envelope insulation, improvement of airtightness, replacement of windows, and ventilative cooling. The result is a portfolio of optimal retrofits that cover the whole range of conservation compatibility. We show that in the analyzed case heritage preservation is compatible with a four-fold reduction in energy needs at a high thermal comfort level. Even higher energy savings are only achievable at the cost of heritage degradation.

Das Beheizen historischer Kirchen ist eine stete Gratwanderung: Für Besucher soll im Aufenthaltsbereich ein gewisser Komfort erreicht werden, während die Kosten beschränkt und Schäden an wertvoller Ausstattung vermieden werden. Dass dies nicht trivial ist, zeigen vielfältig dokumentierte Schadensfälle, beispielsweise zu Schwärzung an Wänden, Salzausblühungen oder abblätternder Fassung. Eine „beste Lösung“ für alle Kirchen gibt es nicht, sehr wohl aber können Kriterien aufgestellt werden, um den Entscheidungsprozess für eine konkrete Kirche zu unterstützen – so die Ergebnisse dieser Arbeit, die neben Raumklimamessungen in 28 Kirchen und dynamischer Simulation auch ein ausführliches Literaturstudium umfasst. Eine wesentliche Rolle spielt neben Kirchenausstattung, Raumgröße, Außenklima und Nutzungshäufigkeit auch das bisherige Raumklima, auf das sich Gebäude und Inventar - unter Umständen seit Jahrhunderten - eingestellt haben.