I ZEB, og som en del av arbeidspakke 5 "Konsepter og strategier for nullutslippsbygg", er det gjennomført en studie av to energikonsepter for boligområdet Ådland i Bergen.

Ådland ligger ved Flesland rett sør for Bergen sentrum. ByBo AS ønsker å bygge ut fra 500 – 800 boliger på området hvor både de enkelte boligene og området som helhet skal oppfylle kriterier for nullutslippsbygg.

I ZEB er det definert ulike ambisjonsnivå for nullutslippsbygg. Den gjennomførte studien anbefaler et ambisjonsnivå ZEB-O som et gjennomsnitt for Ådland området. ZEB-O betyr at området skal være selvforsynt med energi, inklusive elektrisitet og varme, over et år. I tillegg anbefales det at enkeltbygg skal oppfylle ambisjonsnivå ZEB-OM, det vil si at energiproduksjonen på bygget ikke bare tilsvarer det årlige behovet for energi, men hvor den fornybare energiproduksjonen også veier opp fra utslipp av CO2 knyttet til produksjon av byggematerialer. Det anbefales videre at det settes klare spesifikasjoner knyttet til materialbruk for hele området for å oppnå så lavt innhold av iboende CO2 fra materialbruk som praktisk mulig.

To alternative energikonsept er utredet for Ådland; naturlig klimatisering, en bygningskropp med varmetapstall tilsvarende passivhusnivå, solfangere for varmeproduksjon og solceller for elektrisitetsproduksjon er inkludert i begge alternativene. Begge alternativene omfatter også en energisentral som skal stå for hovedandelen av varmeproduksjonen og med et tilhørende nærvarmeanlegg for området. For alternativ 1 benyttes grunnvarmepumper for varmeproduksjon. All elektrisitetsproduksjon kommer fra solceller. For alternativ 2 benyttes en biogass drevet maskin som kombinerer produksjon av elektrisitet og varme (CHP).

Beregninger er utført for årlig energibehov og produksjon av varme og elektrisitet for begge alternativene. Analysen viser at det er mulig å oppnå en ZEB-O ambisjon som et gjennomsnitt for boligområdet Ådland for begge alternativene.

The current state and future challenges of energy and buildings research are explored from the perspective of the social study of science. Major trends in knowledge production are considered for practices within current energy and buildings research. New forms of knowledge production hold the potential to provide clearer strategies to overcome barriers between researchers and practitioners. These are investigated through an explorative survey of researchers based on their own accounts of energy and buildings research, their expectations of future challenges, and their perceptions of ‘good’ science. Two sets of challenges from knowledge production arise for building energy research. First, with an increasing focus on environmental and other impacts of the research, the framing and definition of these extra-scientific factors will become a significant challenge for researchers. Second, as buildings become simultaneously more complex and more connected, the already existing need for the integration of different kinds of expertise will increase further.

Sandwich elements are widely used in the building envelope, in walls and foundations in particular. The thickness of sandwich elements is increasing as the demand for reduced heat loss from the building envelope is required. The building industry is searching for means and alternative materials to reduce the volume of the building envelope, but at the same time obtain the same thermal performance. Sandwich element constructions might be suitable for highly effective insulation materials as VIPs (Vacuum Insulation Panels). The possibilities of optimizing the thermal performance and by the same time decreasing the thickness and reducing the volume of aggregated clay sandwich construction block systems with VIPs has been investigated. Numerical simulations with heat conduction models and also CFD-models have been performed in order to study the optimal design of the block, the influence of thermal bridges and the influence of vertical and horizontal joints on the thermal performance of a wall. The work has resulted in an optimal design for a prototype block which has been produced and general knowledge about the influence of convection in vertical joints. The simulations show that for vertical joints less than 3 mm in width there will be no significant heat transport by convection. The numerical simulations also show that an U-value of 0,08 W/m2K can be achieved for such a system, with a thickness of the block being 300 mm. The work was carried out in the framework of the Norwegian centre for Zero Emission Buildings (ZEB).

Net zero energy buildings (nZEBs) are understood as grid-connected buildings which do not require net inputs of non-renewable energy over a defined period of their life cycle. Energy requirements of nZEBs have until now been assessed based on the impact buildings have on the existing energy system. This paper introduces a new approach to nZEB energy balance that takes into account the actual amount of energy nZEBs require.

Energy balance methods previously proposed for nZEBs are illustrated in a new way and expressed in a series of equations based on a common terminology. Taking a different standpoint on the very logic that lies behind energy calculations; this article presents a new approach to energy balance in nZEBs. The paper highlights the important difference between preventing an increase in the demand for grid energy and ensuring that a building requires no net non-renewable energy. The authors argue that an energy payback approach constitute a more adequate way to tackle the environmental challenges nZEBs are meant to help solving, and to abide to a definition which stipulates that nZEBs should require no net non-renewable energy