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The cost-effectiveness of energy efficiency measures meant to achieve a zero-emission office building is investigated and compared to business as usual energy efficiency measures. The laboratory for zero emission buildings, the ZEB Lab, located in Trondheim, Norway, is an office building designed and built to compensate its lifecycle emissions with the use of a large array of building-integrated photovoltaic panels, pursuing a zero-emissions ambition level. Three design alternatives are investigated by downgrading the building insulation level to the values recommended by the currently enforced Norwegian building code, the byggteknisk forskrift TEK17. A sensitivity analysis of the variation of the installed area of the photovoltaic panels is performed to evaluate if smaller areas give better cost performances. Net present values are calculated by using three scenarios of future increase of electricity price for a time horizon of 20 years. Results show that business as usual solutions give higher net present values. Optimized areas of the photovoltaic panels further increase the net present values of the business as usual solutions in the highest electricity price scenario. The zero-emission ambition level shows a higher net present value than that of the business as usual solutions for a time horizon of at least 36 years.

This work presents the results of a survey and measurement campaign carried on in two wooden buildings in Trondeim, Norway. These are one tower in a student accommodation complex, the Moholt Allmenning, constituted by five CLT towers of 9 floors each, and a mixed CLT-and-timber-frame educational building, the Haukåsen kindergarten. Both buildings comply with the Norwegian Passive house standard and the kindergarten complies with the BREAAM certification as well. Questionnaires focussing on the buildings' users thermal, acoustic, and visual comfort, and on the IAQ were submitted. Measurements of the indoor operative temperature and CO2 levels were performed. The measurements showed that both buildings are in the NS 15251 Class I with regards to the thermal environment, in both summer and winter. The questionnaires that the perceived dissatisfaction is somewhat higher than that assessed in the measurements, leading to a lower rating, especially in the student housing. One of the most reported issue in the student housing was the noise level, which resulted in 28% of student dissatisfied.

The objective of this paper is to report and analyse strategies for cost reduction, design processes, and procurement models of one wooden nearly Zero Energy Building (nZEB) in Norway. The building investigated in this paper is the Moholt Allmenning, a newly-built student accommodation located in Moholt, Trondheim. Interviews with the building's owner and the contractor were carried out to obtain information on the decision-making process during the procurement phase, the planning phase, and the execution phase. The results show that the environmental goal and the criteria set for the use of wood in the tender announcement were a critical driving force for choosing cross laminated timber (CLT) in the final design. The results also show that the cost of using CLT in student residences is competitive against using concrete and steel. Given the requirement of little greenhouse gas (GHG) emissions from materials production in nZEBs, the use of CLT is however a better choice. The objective of this paper is to report and analyse strategies for cost reduction, design processes, and procurement models of one wooden nearly Zero Energy Building (nZEB) in Norway. This publication is part of the dissemination activities of the EU Horizon 2020 project NERO, whose scope is to demonstrate the feasibility of cost reduction of nZEBs built with wood in the Nordic Countries. Case buildings from Estonia, Finland, Norway, and Sweden are studied with respect to their technological solutions, energy use, and construction cost. The Norwegian building investigated in this paper is the Moholt Allmenning, a newly-built student accommodation located in Moholt, Trondheim. Interviews with the building's owner and the contractor were carried out to obtain information on the decision-making process during the procurement phase, the planning phase, and the execution phase. The results show that the environmental goal and the criteria set for the use of wood in the tender announcement were a critical driving force for choosing cross laminated timber (CLT) in the final design. The results also show that the cost of using CLT in student residences is competitive against using concrete and steel. Given the requirement of little greenhouse gas (GHG) emissions from materials production in nZEBs, the use of CLT is however a better choice.

The application perspective of aerogel glazings in energy efficient buildings has been discussed by evaluating their energy efficiency, process economics, and environmental impact. For such a purpose, prototype aerogel glazing units have been assembled by incorporating aerogel granules into the air cavity of corresponding double glazing units, which enables an experimental investigation on their physical properties and a subsequent numerical simulation on their energy performance. The results show that, compared to the double glazing counterparts, aerogel glazings can contribute to about 21% reduction in energy consumptions related to heating, cooling, and lighting; payback time calculations indicate that the return on investment of aerogel glazing is about 4.4 years in a cold climate (Oslo, Norway); moreover, the physical properties and energy performance of aerogel glazings can be controlled by modifying the employed aerogel granules, thus highlighting their potential over other glazing technologies for window retrofitting towards energy efficient buildings. The results also show that aerogel glazings may have a large environmental impact related to the use of silica aerogels with high embodied energies and potential health, safety and environment hazards, indicating the importance of developing guidelines to regulate the use of aerogel glazings.

The paper aims to investigate whether it is possible to achieve a net Zero Emission Building (nZEB) by balancing emissions from the energy used for operation and embodied emissions from materials with those from on-site renewables in the cold climate of Norway. The residential nZEB concept is a so-called all-electric solution where essentially a well-insulated envelope is heated using a heat pump and where photovoltaic panels (PV) production is used to achieve the CO 2eq balance. In addition, the main drivers for the emissions are revealed through the CO 2eq calculation for a typical Norwegian, single-family house. This concept building provides a benchmark rather than an absolute optimum or an architectural expression of future nZEBs. The main result of this work shows that the criteria for zero emissions in operation (ZEB-O) is easily met, however, it was found that the only use of roof mounted PV production is critical to counterbalance emissions from both operation and materials (ZEB-OM). The results show that the single-family house has a net export to the electric grid with a need for import only during the coldest months. In the next stage of the work, the concept will be further optimised and the evaluation method improved.