Publications

Due to the significant impact of the building sector on greenhouse gas emissions, newer and stricter regulations aimed at reducing total energy use in buildings have appeared in the last few years. In the European context, all the new constructions will thus soon be asked to be nearly Zero Energy Buildings (nZEB). In order to reach this target, new concepts and technologies capable of further improving buildings’ energy efficiency need to be developed. A very promising strategy to overcome current technology limitations is represented by revisiting the conventional approach that considers the building as a static object and moves towards…

Framing Transitions
Authors: Publication Year: 2013


Green Brøset - Green Swimming Pool
Authors: Publication Year: 2013


Brøset Klimasenter
Authors: Publication Year: 2013


Standards and regulations can play a central role in policies to achieve environmentally sound and energy-efficient buildings. This paper sets out to explore how consulting engineers relate to standards designed to impose sustainability in the construction of new buildings and in waste management. The paper addresses four cases of engineering practices. The first case describes practical skills and tools involved in what the engineers considered as ‘normal’ practices when performing energy calculations in the development of new buildings. The second and third cases deal with energy in new buildings as well, but address practices that supported or enabled the engineers…

We are currently witnessing in the Norwegian building sector (and elsewhere) the transition from isolated and heterogeneous sustainable building projects carried out in protected niches (e.g pilot projects) to more sustainable buildings becoming mainstream. According to scholars studying sustainable transitions this is the moment in which a dominant design catches on, replacing and displacing other more or less sustainable alternatives. Within this process, in the Norwegian case, the principles behind the passive house play a salient role. In fact, only recently a government white paper has called for "passive house levels" to become part of the building code by 2015.…

Stricter energy regulations for energy use in buildings require new construction to be equipped with increasingly thicker insulation layers and minimal surfaces for glazing in cold climates. In recent years a new type of window has been proposed as a way to overcome the notoriously low thermal performance of transparent surfaces. In order to reach such performances, this glazing type has been equipped with monolithic aerogel as the glass-pane filling. The scope of this study is a comprehensive analysis of greenhouse gas emissions from the partial substitution of typical triple-glazing-with-argon units with double-glazing-with-monolithic-aerogel units in residential building upgrades. A social…

In the pursuit of stricter energy standards for buildings to reduce their share of energy use, the use of highly efficient insulation materials like aerogel and vacuum insulation has opened a path towards lighter construction in energy retrofitting, whereas commercially available materials, such as EPS and mineral wool, result in massive wall solutions. However, these new materials are notoriously energy intensive in production, resulting in high levels of embodied energy and emissions. This work describes a comprehensive greenhouse gas analysis of the use of different insulation materials applied to residential building upgrades to passive house standard. It estimates the potential…

Experience with low-energy and passive house buildings forms the basis for the further development of zero-emission buildings. A post-occupancy evaluation of the Løvåshagen cooperative is therefore conducted by means of user surveys and measurement of indoor climate parameters, energy use and window opening time. The goal of the post-occupancy evaluation is to obtain information about how occupants use and experience low-energy and passive house dwellings, especially with regard to heating and ventilation. In addition, the impact of user behavior on the indoor climate and energy use will be assessed. In this paper, the results of the user survey regarding user…

The main definition of a Powerhouse is a building that shall produce at least the same amount of energy from on-site renewables as the energy used during construction, manufacturering of materials, renovation, demolition and operation exclusive energy used during manufacturering of equipment such as PCs, coffee machines etc. In addition the exported energy shall in average not have less quality than the imported energy. This implies that produced and exported electricity can offset corresponding amount of imported energy for both electricity and thermal purposes, while produced and exported thermal energy cannot offset imported electricity. The building shall also as a…

The aim of the Norwegian research centre on Zero Emission Buildings(ZEB) is to develop competetive products and solutions of buildings with zero emission of greenhouse gases related to their production, operation and demolition. However, to develope solutions and concepts for zero emission buildings it is first necessarry to develop a sound definition of ZEB (for single buildings, and also cluster of buildings). During the first 3 years of the centres running, significant work have been done to adress different issues related to the ZEB-definition, among them defining CO2 factors for various energy wares. Work done in the International Energy Agency…

The German definition of the passive house standard is strongly related to the air-heating (AH) concept, while this concept is not explicitly connected with the Norwegian definition (NS 3700 standard). As AH presents an opportunity for space-heating (SH) simplification, the AH potential is here investigated in the Norwegian context. The questions of the required AH temperatures, of the temperature distribution between rooms and the influence of losses from ventilation ducts are investigated using detailed dynamic simulations (here using TRNSYS). This is done using a typical detached house typology, both considering different building construction materials as well as different climate zones…

In order to minimize the energy use for heating, passive houses for residential use are constructed using heavy insulation. In addition, they have minimal air leakages and no vents in exterior walls for direct supply of fresh air, and thus, mechanical ventilation systems are a mandatory requirement in such buildings. With the aim of reducing energy use, efficient energy recovery from used air will be of high importance. In residential buildings with several living units, centralized air handling units are regarded as the most energy efficient system. However, to prevent odours to transfer between apartments it is important to avoid…

A simple, mild, and effective template approach has been used to produce hollow silica nanospheres with controlled sizes ranging from 40 to 150 nanometers. The obtained powders showed systematic variations in measured thermal conductivity, with values down to 0.024 W/(mK) so far, with en expressed goal to reach below 0.020 W/(mK). Surface hydrophobization was successfully performed. Thus, hollow silica nanospheres are considered to be promising building blocks for new hydrophobic, superinsulating materials.

Bygger Norges første plusshuss
Publication Year: 2013

Hele 1556 kvadratmeter med solceller gjør at Norge får sitt første plusshus i Bærum.   Artikkelen skrevet av Caroline Drefvelin.

Window panes, glass structures and electrochromic windows in buildings may be characterized by a number of solar radiation glazing factors, i.e. ultraviolet solar transmittance, visible solar transmittance, solar transmittance, solar material protection factor, solar skin protection factor, external visible solar reflectance, internal visible solar reflectance, solar reflectance, solar absorbance, emissivity, solar factor and colour rendering factor. Comparison of these solar quantities for different glass fabrications enables one to evaluate and thus select the most appropriate glass material or system for the specific buildings and applications. Measurements and calculations were carried out on various glass materials, including three electrochromic window devices,…

The role of tunnel K+ ions on the growth and stability of tunnel-structured cryptomelane-type MnO2 nanofibers (denoted as cryptomelane nanofibers hereafter) has been discussed by means of X-ray diffraction and electron microscopy. Cryptomelane nanofibers with typical diameters of 20–80 nm and lengths of 1–6 μm have been synthesized by means of a simple hydrothermal reaction of KMnO4 and MnSO4 aqueous solutions at 140 °C. The growth of cryptomelane nanofibers under hydrothermal conditions follows a dissolution–recrystallization process and involves a morphological transformation from a layered precursor to the tunnel-structured cryptomelane, in which the K+ ions play important roles in templating and…

In order to reach the goal of a zero emission building (ZEB), CO2 emission data has to be made available and verified for traditional building materials, new ‘state-of-the-art’ building materials and the active elements used to produce renewable energy. However, an initial literature review found that although there are databases of embodied carbon values for most building materials, the range in results for some materials are varied and inconsistent. This paper follows on from previous work on the development of a transparent and robust method to calculate CO2eq emissions of the materials used in the concept analysis of the ZEB…

The demands for both thermal comfort and reduced energy consumption in buildings have become a major driving force for the increased use of advanced building automation and control systems (BACS). In the on-going development of Zero Emission Buildings (ZEBs), it seems to be a common understanding that such systems are needed in order to save energy and reach the zero emission goals, and that energy consumption for their operation is negligible compared to the building needs and the energy saving potential BACS causes. However, sensors and actuators in automation and control systems require electricity to operate, and both the environmental…

Framtidas isolasjon
Publication Year: 2013


Improving energy efficiency in dwellings is generally seen as the low-hanging fruit of climate change mitigation. In particular decreased heat loss through better insulation is suggested as one of the most cost-effective means to achieve the ambitious national and international goals of climate gas reduction. However, the literature shows that a profitable technological solution is not sufficient to reach the energy goals. Aspects such as a lack of information, unobserved costs, and heterogeneity among users can compromise the success of technical innovation. Still, there are successful concepts that drive the technological development in the construction sector. The Passive House is…

Carbon Debt and Carbon Payback time have recently been introduced into the Norwegian debate on greenhouse gas emissions, challenging the established view that Biofuels are carbon neutral. This report demonstrates that these new concepts are primarily a reflection of how the temporal system boundaries for CO2 emissions from biofuels are viewed. In a short term perspective it is possible that CO2 emissions from biofuels may have a non-zero short term climate effect, even though biofuels will be carbon neutral on the order of a century. Two alternative, more useful new concepts for analysis of climate effects of biofuels are described…

The passive house (PH) standard is seen as the future minimal requirement for buildings in Norway, where a specific definition has been developed (NS 3700). Nevertheless, the relation between this standard and air heating (AH) is not clear while both concepts are often associated. The present contribution investigates challenges for AH in terms of thermal dynamics (e.g. temperature distribution and control) as well as the feasibility of the AH concept. This is done using detailed dynamic simulations on a typical detached house typology. Results show some limitations of the AH concept in Nordic countries, as well as provide guidelines for…

Single-crystalline sodium tungsten bronze (Na-WO3) nanorods with typical diameters of 10−200 nm and lengths of several micrometers were prepared via hydrothermal synthesis. The as-prepared Na-WO3 nanorods crystallized in a hexagonal structure (space group P6/mmm) with unit cell parameters a=7.3166(8) Å and c= 3.8990(8) Å and elongated along the ⟨001⟩direction. Chemical analyses indicated a stoichiometry of Na0.18WO3.09·0.5H2O, revealing the existence of tunnel Na+ ions and water molecules in the structure, as confirmed also by the vibrational spectroscopic study. The as-prepared Na-WO3 nanorods exhibited a direct-allowed electronic transition with band-gap energy of about 2.5 eV, which allows a visible-light-driven photochromism related to…

Design principles in Net-ZEB considers the local energy infrastructure as virtual storage leading to large amount of energy exchange with the grid. Nonetheless, with high Net-ZEB penetration scenarios, such exchange could compromise the effectiveness of Net- ZEB concept in a total energy infrastructure. As the current market trends, heat pumps along with photovoltaics are seen as an emerging energy supply solutions in Net-ZEB buildings, effectiveness of an all-electric Net-ZEB (that is using air-to-water heat pump with photovoltaic) is analysed. Two concrete control cases of energy storage (compared to reference case) to assess Net-ZEB ability to self-consume vs. grid empowerment are…

Single-crystalline sodium tungsten bronze (Na-WO3) nanorods with typical diameters of 10–200 nm and lengths of several of microns were prepared via hydrothermal synthesis. X-ray diffraction data showed that the as-prepared Na-WO3 nanorods crystallize in a hexagonal structure (space group P6 / mmm) with unit cell parameters a = 7.3166(8) Å and c = 3.8990(8) Å, and elongate along the <001> direction. The Na-WO3 nanorods had a mean chemical composition of Na0.18WO3.09·0.5H2O. The Na-WO3 nanorods exhibited a typical cathodic coloration related to proton insertion, indicating their potentials in electrochromic smart window applications.

Large scale energy efficient renovation of buildings is one of the most important tools to realize the society's need of a more sustainable building stock. Most Norwegians own their own homes. Therefore private homeowners are a focus group for the government urging to accelerate the dwelling energy efficiency rates. Success factors were identified in the in-depth study of the decision process of eleven homeowners. Large differences in energy use due to the building's condition and the occupants' behavior was encountered in the sample. Only homeowners who were conscious consumers and did not trust expert advice or that had special knowledge…

The Research Centre on Zero Emission Buildings - Annual Report 2012

The demands for both thermal comfort and reduced energy consumption in buildings have become a major driving force for the increased use of advanced building automation and control systems (BACS). In the on-going development of Zero Emission Buildings (ZEBs), it seems to be a common understanding that such systems are needed in order to save energy and reach the zero emission goals, and that energy consumption for their operation is negligible compared to the building needs and the energy saving potential BACS causes. However, sensors and actuators in automation and control systems require electricity to operate, and both the environmental…

Norske boliger råtner på rot
Publication Year: 2013

Vi bruker milliarder på estetiske oppgraderinger og praktiske løsninger, men mangler kunksap o lønnsom bruk av oppussingskronene. Artikkelen er skrevet av Marit Tronier Halvorsen, Oslo

Statlige Entra fremmer et nytt powerhouse-prosjekt på Brattøra. Noe mindre enn det forrige, men likevel tolv meter høyere enn tillatt i reguleringsbestemmelsene. Artikkelen er skrevet av Hermann Hansen

Powerhouse #1 is planned to become the first and northernmost energy-positive office building. An alliance of companies within the Norwegian construction industry has been established to reach this ambition. Partnering has been suggested as a means to improve performance in general within the construction industry. Studies reveal that the industry is yet to yield the positive effects that have occurred in other industries. Strategic alliances such as Powerhouse are an exception within Norwegian construction industry. The paper analyses the case of Powerhouse #1 regarding collaborative working and experienced effects to the energy performance of the project. The material consists of…

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