Energy upgrading of wooden dwellings to nearly zero energy level

(OPPTRE) was to propose a nearly Zero Energy Building (nZEB) level for the renovation of wooden dwellings that have high architectural quality, are cost-efficient and low-carbon. Furthermore, barriers and driving forces for how nZEB renovation can capture a significant market share are identified. OPPTRE was a multidisciplinary project organized in five work packages (AP1-5). An architectural competition was a core activity. Teams with architects, consultants and contractors participated. WP1 Architecture and housing quality: For the architectural competition six teams were each assigned one house from 1950-1990 where homeowners had specific wishes and needs. Two winners were chosen as described in the jury report NAK 527_E. Researchers from WP1 and WP5 conducted 20 interviews with homeowners and teams, partners, the jury and other key players. The interview material is basis for to articles in process (Combining energy upgrading with improved housing quality? can we achieve both? Arkitektur N 2022 vol 4). Important findings are that the competition show good examples of nZEB renovation, multidisciplinary teams were crucial for the good results, architects play an important role in energy upgrading with space efficient and flexible design but communication between professionals and homeowners is crucial to motivate homeowners and increase their understanding / knowledge. WP2 Optimisation of building envelopes: An nZEB level has been proposed based on practice in the industry; TEK17, but as delivered energy. Results from the competition is evaluated and showed that this level is suitable for the purpose. The analysis is presented in a conference paper for the Building Physics Conference (IBPC 2021). A tool for assessing the risk of moisture damage during upgrading is developed in cooperation with OPPTRE partners. The tool has been presented at Norsk Bygningsfysikkdag 2021 and a SINTEF technical report is published; "Risikoverktøy for fuktsikker oppgradering av småhus". AP3 Ventilation, heating, and energy supply: The competition is analysed regarding energy use, ventilation, and indoor environment. Despite good internal collaboration, the teams seem to have selected energy measures for the building envelope and the HVAC system separately. Occupants often want colder bedrooms and/or bedrooms with natural ventilation. The conclusions define two main research questions of the PhD work: (1) How is the indoor environment in bedrooms with natural ventilation in renovated buildings? (2) What is the balance between costs, energy performance and CO2 emission for the heating and ventilation systems based on quantitative data? For (1), a MSc (2020) developed a measurement method. The PhD work has further improved the measurement method for indoor environment of bedrooms, and field measurements are completed in 2021. Results are presented in two conferences in 2021 (Cold Climate HVAC and Healthy Buildings 2021) and will lead to a first journal paper. Also, energy performance with natural ventilations in bedrooms is investigated, and presented at the CLIMA22 conference. For (2), two MSc (2021 and 2022) have established a cost database for HVAC components and evaluated their lifecycle costs (LCC). The PhD work has compared LCC and energy performance between different HVAC combinations, and also analysed the balance between measures on the building envelope versus HVAC-systems. The cost-efficiency analysis is presented at the CLIMA22 conference and will lead to a second journal paper. WP4 Life cycle assessment (LCA) and life cycle cost analysis (LCCA): The contributions in the architect competition were documented, using the LCA tool developed for the competition. A sensitivity analysis has been performed for two key parameters: CO2-factor for the electricity consumption (25-130 g CO2/kWh) and time perspective (20-60 years). The initial results are presentation on life cycle assessment and carbon footprint for a NAL course on renovation of small wooden dwellings and in a SINTEF technical report and will be the basis for a scientific article in 2022. WP5 Innovation system analysis, policy measures and innovative business model: Interviews are conducted in cooperation with WP1, and results are discussed in workshops with the partners in OPPTRE. This is the basis for a scientific article, final report, and a chronicle. Important findings are that measures should be aimed at ensuring that energy upgrades take place within the existing building envelope. The new room layouts in the architectural competition shows that the homeowner's needs can be satisfied to a large extent without increasing the living area. Business models are limited by structures in the market as well as high demand for new dwelling. For architects, it seems sensible, but not yet widespread, to offer energy advice as an entrance to the market. www.opptre.no.

Arkitektkonkurransen førte til debatt om klimafotavtrykk Interesse for energioppgradering med arkitektonisk kvalitet Kunnskapsoverføring mellom forskningsmiljøer og praksisfeltet Oppmerksomhet om ventilasjon på soverom Mange har lave temperaturer i soverom med åpent vindu Mange har lav luftkvalitet i barne- og tenåringsrom Store pris- og kostnadsvariasjoner for VVS-løsninger VVS-løsninger kan være mer kostnadseffektive enn tiltak på bygningskroppen Klimagevinst for energioppgradering Kunnskap for aktører med ansvar for bevaring av bygg Arkitektenes rolle er viktig for arealeffektive løsninger i stedet for påbygg og tilbygg Klimamessig mer fornuftig å oppgradere enn å rive og bygge nytt Forretningsmodeller er begrenset av strukturer i markedet og høy etterspørsel etter nybygg Arkitektene bør tilby energirådgivning som en inngang til markedet Virkemidler bør rettes mot oppgradering innenfor eksisterende bygningskropp

The goal of the KPN project, Energy upgrading of wooden dwellings to nearly zero energy level (OPPTRE), is to propose a nearly Zero Energy Building (nZEB) level for the renovation of wooden dwellings. To this end, we will identify nZEB concept designs that have high architectural quality, are cost-efficient and low-carbon. Furthermore, we will identify barriers and driving forces for nZEB renovation, capturing a significant market share. The scope is small wooden dwellings, responsible for more than half of the total energy use in the Norwegian building stock. These can contribute significantly to the national target of 10 TWh/year energy saving by 2030 for existing buildings. The project will employ a multidisciplinary approach with cooperation across five work packages that address i) architecture and qualities in dwellings, ii) optimisation of building envelopes, iii) HVAC and energy generation, iv) life cycle assessment (LCA) and life cycle cost analysis (LCCA), and v) innovation system analysis and business model research. The project includes Scandinavian/Baltic cooperation on issues and knowledge related to wooden dwellings. The research tasks are organised in phases, with an architecture competition at the core. In advance of the competition it is necessary to i) identify archetype cases for wooden houses from 1950-1990, ii) develop an initial definition of nZEB level renovation, and iii) develop renovation concepts and simplified tools to support energy calculations, LCA and LCCA in the competition. Next is the architecture competition, to find examples of innovative energy upgrading solutions. Finally, evaluation of results and deduction of general principles for nZEB level renovation. The project will create knowledge for nZEB level renovation of wooden dwellings for home-owners and builders, and knowledge for public and private decision makers on business models, regulations and incentives that can lead to market uptake of nZEB renovation towards 2030.