Energy Upgrading of Basement ExteriorWalls: The Good, the Bad and the Ugly

Most of today’s buildings will still be in use in 2050 and upgrades should therefore contribute to reducing energy consumption and carbon footprint. This paper addresses a challenge for upgrading of basement exterior walls of single-family dwellings, where ordinary retrofit insulation can lead to the basement wall protruding from the existing outer wall. For some, this will be an aesthetic barrier for an energy upgrade (an “ugly” solution). Superinsulation may solve this challenge without compromising the energy performance. This study analyses energy, cost and carbon footprint, to identify under which conditions upgrading with vacuum insulation panels (VIP) can be a preferred solution. Three alternatives are analysed in a parametric model: ordinary upgrade with XPS (the aesthetically “ugly”), upgrade with VIP above ground and XPS below ground (the aesthetically “good”), and iii) no upgrade (the “bad”, as it does not contribute to reducing energy consumption). Results show that using VIP and XPS to perform energy upgrade of a basement exterior wall may lead to an aesthetically more pleasing solution than with only XPS, but that it will lead to higher carbon footprint and higher costs. The least favourable option is to install a drainage system without doing an energy upgrade, which will have negative impact for energy use, carbon footprint and life cycle cost.publishedVersio

Optimization of thermal insulation thickness pertaining to embodied and operational GHG emissions in cold climates – Future and present cases

Determining the optimal insulation thickness is useful for designing zero-emission buildings (ZEB) to minimize the environmental impacts. The energy required to heat buildings in cold climates is relatively high. Substantial reductions in the total energy usage of a building can be achieved by reducing the U-value of the external surfaces. Increasing the insulation thickness reduces the operational CO2 emissions, although simultaneously increases the embodied CO2 emissions from materials. To mitigate climate change, Norway and Denmark are trending towards stricter regulations to limit energy use in buildings. However, these countries have no current regulations in the building codes for limit embodied CO2 emissions from materials. This study analyzes the influence of the energy emission factor and future climate change (scenarios?) on the optimal insulation thickness. We used three independent models for case studies in Greenland and Norway. The differences between the case studies highlight the influence of model parameter choices, such as indoor climate, energy emission factor and material emissions, whereas the similarities may be used to analyze the problem from a broader perspective. The results show that optimal insulation thickness calculations are most valuable for case studies in which the energy emission factor is low. Considering energy emission factors above 25–30 g CO2eq/kWh, operational emissions dominated the calculation results in all case studies.publishedVersio

Rammeverk for klimatilpassing av bygningar

Forord. Denne rapporten presenterer eit rammeverk for klimatilpassing av bygningar. Rammeverket er meint å framheve myndigheitskrava til klimatilpassing, å vise til verktøy som kan vere til nytte for å verifisere at valte løysningar held, samt å presentere ei systematisk tenking for handtering av klimatilpassing. Rammeverket er fysisk vinkla og seier ikkje noko om prosess, organisering og samhandling. Rammeverket er eit resultat av ein kontinuerleg aktivitet gjennom heile den åtte år lange prosjektperioden til Klima 2050. Temasamlingane oppsummerte i Klima 2050 Note 5, 22, 62, 76 og 127 har alle vore sentrale i utviklinga av rammeverket. Utviklinga har også nytt godt av Norgeshus sitt IPN-prosjekt Verktøykasse for klimatilpasning av boliger og masteroppgåvene til Torun Krangsås Vikan (Vikan 2016) og Julie Sandli Danbolt (Danbolt, 2018). Den grunnleggande rammeverksidéen vart presentert og diskutert i ein internasjonal vitskapeleg konferanse av Lisø et al. (2017). Alle tilbakemeldingar i prosessen har vore svært nyttige i utviklinga av rammeverket. Klima 2050 – Reduksjon av samfunnsrisiko forbundet med klimaendringar på det bygde miljø er eit senter for forskingsbasert innovasjon (SFI) finansiert av Norges forskningsråd og partnerane i konsortiet. SFI-statusen gjer langsiktig forsking i nært samarbeid med privat og offentleg sektor mogleg, samt med andre forskingspartnarar som har som mål å styrke Norges innovasjons- og konkurranseevne innan klimatilpassing. Samansettinga av konsortiet er viktig for å kunne redusere samfunnsrisikoen forbundet med klimaendringar. Senteret vil styrke bedriftene sin innovasjonskapasitet gjennom fokus på langsiktig forsking. Det er også eit klart mål å legge til rette for tett samarbeid mellom FoU-aktive bedrifter og framifrå forskingsgrupper. Det blir lagt vekt på utvikling av fuktbestandige bygningar, overvannshandtering, blågrøne løysingar, tiltak for førebygging av vannutløyste skred, sosioøkonomiske insentiv og beslutningsprosessar. Både ekstremvêr og gradvise endringar i klimaet blir sett på. Vertsinstitusjonen for SFI Klima 2050 er SINTEF Community, og senteret blir leia i samarbeid med NTNU. Dei andre forskingspartnerane er Handelshøyskolen BI, Norges Geotekniske Institutt (NGI) og Meteorologisk institutt (MET Norge). Industripartnerane representerer viktige delar av norsk byggenæring; rådgivarar, entreprenørar og produsentar av byggevarer og teknologi: Skanska Norge, Multiconsult ASA, Mesterhus, Norgeshus AS, Leca Norge AS, Isola AS og Skjæveland Gruppen AS. Senteret inkluderer også viktige offentlege byggherrar og eigedomsutviklarar: Statsbygg, Statens vegvesen, Jernbanedirektoratet og Avinor AS. Sentrale aktørar er også Trondheim kommune, Norges vassdrags- og energidirektorat (NVE) og Finans Norge. Ein spesiell takk til Norgeshus i utviklinga av risikovurderingsoversikta presentert i rapporten og til Julie Sandli Danbolt som i si masteroppgåve (Danbolt, 2018) kartla relevante og nyttige hjelpemiddel ved prosjektering av klimatilpassa bygningar.publishedVersio

A parametric study of the energy performance and carbon footprint of super-insulation in terrace constructions

Energy requirements for buildings are continually tightened, as seen in the ambitions to introduce near zero-energy building (nZEB) requirements in Norwegian and European building codes from 2020. One consequence of this is an increased use of insulation. However, standard insulation may cause challenges in many circumstances, for example where increased wall dimensions lead to reduced daylight levels or where increased insulation leads to increased floor height. Super-insulation materials are a possible solution to these challenges. Although several super-insulation products exist on the market, there is still a need for proven system solutions that provide the required level of insulation, along with reduced thickness in the constructions. An additional challenge is that these solutions should also be cost-effective and carbon-effective. The economic benefits should outweigh the costs and the carbon footprint should ideally be reduced, but at least not significantly increased. To analyse the potential of super-insulation, we have performed a parametric case study of terrace constructions based on super-insulation and compared these with a baseline solution. The terrace construction uses vacuum insulation panels (VIP) as the main insulation. The top plate insulation is tapered mineral wool, aerogel is used in the edges and on top of the construction there are wood tiles. The parameters that have been varied are i) terrace dimensions, ii) width of the edge with non-combustible aerogel, iii) the thickness of the VIP layer, iii) the slope of the tapering, and iv) the heat conductivity of the VIP panels. To evaluate the benefits of the super-insulation an analysis of energy performance in the use phase has been done. As the energy efficiency of the super-insulation solution is improved, this gain can be used either to reduce thickness or to increase energy performance. Both these will have an impact on the costs. To evaluate the environmental performance of the solution a screening LCA has been performed, with focus on the carbon footprint. The results of the case study show under which circumstances the super-insulation solution has better performance than the baseline, and vice versa. Key parameters that drive energy performance and carbon footprint are identified, providing suggestions for further research.publishedVersio

Våtere klima gjør massivtretak utsatt for fukt

Bygging med massivtreelementer blir mer og mer vanlig, og med våtere vær i vente bør bransjen skjerpe fokuset på fuktsikker byggeprosess. Undersøkelser viser nemlig at innebygd nedbør i massivtretak kan ta årevis å tørke ut

Built-in moisture in cross-laminated timber roofs – a field study

Cross-Laminated Timber (CLT) elements have had a growing popularity in recent years due to i.e. low carbon footprint, low weight and efficient construction time. However, the elements are sensitive to moisture and prone to organic growth if not treated properly or if used incorrectly. Roof slabs are particularly exposed, as they have a large area of exposure and the horizontal orientation doesn't allow rainwater run-off. The efforts made to protect CLT-roofing elements by Norwegian contractors vary widely, as there are few guidelines and little long-term experience. A field study of CLT-roofs on existing buildings was conducted to investigate the conditions after some years in service. The study includes inspection and moisture measurements of CLT elements from the exterior side in 10 building projects 1-9 years old from two regions of Norway. The contractor of each project was interviewed in order to assess the extent of climate exposure and protection measures during construction. The results indicate a correlation between water content, building age and exposure level during construction. There is a clear indication that the drying time for built-in moisture in CLT roof constructions are slow. Keeping built-in moisture to a minimum is therefore paramount

Våtere klima gjør massivtretak utsatt for fukt

Bygging med massivtreelementer blir mer og mer vanlig, og med våtere vær i vente bør bransjen skjerpe fokuset på fuktsikker byggeprosess. Undersøkelser viser nemlig at innebygd nedbør i massivtretak kan ta årevis å tørke ut.publishedVersio

Thermal Performance of Insulated Constructions—Experimental Studies

Buildings that are designed to meet high-energy performance requirements, e.g., passive houses, require well-insulated building envelopes, with increased insulation thicknesses for roof, wall and floor structures. We investigate whether there are differences in the efficiency of thermal insulation materials at different moisture levels in the insulation and if there is a larger or smaller risk of natural convection in wood-fibre based insulation than in mineral wool. The work has mainly been performed by use of laboratory measurements included permeability properties and full-scale measurements of thermal transmittance of mineral wool and wood-fibre insulated constructions. In addition, calculations have been used to calculate resulting effects on the thermal performance of constructions. Results showed that the thermal conductivity was unaffected by moisture in the hygroscopic range. The air permeability was found to be approximately 50% higher for the wood-fibre insulation compared to mineral wool insulation. Measurements showed that the largest U-values and Nusselt numbers were found for the wall configuration. Calculation of the U-value of walls showed that in order to achieve the same U-value for the wood-fibre insulated wall as the mineral wool, it is necessary to add 20 mm insulation to the 250 mm wall and approximately 30 mm for the 400 mm wall.publishedVersio

A parametric study of the energy performance and carbon footprint of super-insulation in terrace constructions

Energy requirements for buildings are continually tightened, as seen in the ambitions to introduce near zero-energy building (nZEB) requirements in Norwegian and European building codes from 2020. One consequence of this is an increased use of insulation. However, standard insulation may cause challenges in many circumstances, for example where increased wall dimensions lead to reduced daylight levels or where increased insulation leads to increased floor height. Super-insulation materials are a possible solution to these challenges. Although several super-insulation products exist on the market, there is still a need for proven system solutions that provide the required level of insulation, along with reduced thickness in the constructions. An additional challenge is that these solutions should also be cost-effective and carbon-effective. The economic benefits should outweigh the costs and the carbon footprint should ideally be reduced, but at least not significantly increased. To analyse the potential of super-insulation, we have performed a parametric case study of terrace constructions based on super-insulation and compared these with a baseline solution. The terrace construction uses vacuum insulation panels (VIP) as the main insulation. The top plate insulation is tapered mineral wool, aerogel is used in the edges and on top of the construction there are wood tiles. The parameters that have been varied are i) terrace dimensions, ii) width of the edge with non-combustible aerogel, iii) the thickness of the VIP layer, iii) the slope of the tapering, and iv) the heat conductivity of the VIP panels. To evaluate the benefits of the super-insulation an analysis of energy performance in the use phase has been done. As the energy efficiency of the super-insulation solution is improved, this gain can be used either to reduce thickness or to increase energy performance. Both these will have an impact on the costs. To evaluate the environmental performance of the solution a screening LCA has been performed, with focus on the carbon footprint. The results of the case study show under which circumstances the super-insulation solution has better performance than the baseline, and vice versa. Key parameters that drive energy performance and carbon footprint are identified, providing suggestions for further research

Klimatilpasning gjennom FDV

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