Energy efficient dwellings of the future
Introduction Buildings have a significant impact on the environment through resource and energy use, but also on human health and productivity. Energy performance is one criteria used to assess sustainable buildings, which always has been important in cold climates as in the Nordic countries. To meet the goals in the directive 2010/31/EU (EPBD recast) on the energy performance of buildings, the building sector in Europe now faces a transition towards more energy efficient buildings. By 2021, all new buildings should be Nearly Zero-Energy Buildings. Member states are also required to “stimulate the transformation of buildings that are refurbished into nearly zero-energy buildings�. Building codes in many EU-countries have started to reflect this, with bigger requirements on energy performance and its verification. North Pass, Application of the local criteria/standards and their differences for very low-energy and low energy hoses in the participation countries, presents a state-of-the-art review on local building regulations and standards currently used in some European countries. It shows that many of the Scandinavian countries put some sort of requirement on energy use in their building codes and have started to develop specifications for low energy buildings. Besides specifications and requirements, analyzing and verifying building energy performance has also a very important part in achieving energy efficient buildings. Concern has been raised by P Ekins and E Lees, in The impact of EU policies on energy use in and the evolution of the UK built environment, that the transition of the EPBD to national legislations is going slower than expected, asking for more monitoring and enforcements to ensure compliance.
Ingrid Allard Department of Applied Physics and Electronics UmeĂĽ University
Research The PhD-project will be a contribution to the debate on how to create sustainable dwellings for the future, facing the global environment issues and energy problems of today, with a focus on cold climate and single family buildings.
Part 1 - Review A first step towards better building energy performance is to assess the existing requirements today. Current energy-requirements for buildings are mapped for three Nordic countries; Sweden, Norway and Finland; both in building codes and passive house specifications. This illustrates the difference between minimum requirements and “best practice” today. Although the three Nordic countries have similar climate and building traditions, the definitions of energy performance in their respective building codes are quite different. This makes comparisons across national borders difficult and inhibits the progress towards energy efficient buildings. Methods for verification and analysis of energy performance are also reviewed. Since air tightness is an important part of energy efficiency, methods for air tightness analysis and verification are reviewed separately. The goal is to discuss advantages and disadvantages of the methods, find shared methods (or parts of methods) and possibilities for the future.
Part 2 –Calculations Calculation methods for energy verification are chosen from the review and tested. The aim is to compare the three countries definitions of energy performance, by applying them to a practical example and assessing the differences. The building codes are compared by evaluating the same single-family building according to the methods described in each building code. The simulation results are analyzed to find out how the different definitions of energy performance in the building codes reflect the buildings energy use. The simulations are also compared to measurements of the same building, to evaluate not only the differences between the three countries, but also between a verification methods based on simulations and one based on measurements.
Part 3 – Measurements One measurement methods for energy verification are chosen form the review and tested. Two single family houses are chosen for the measurements; one example of best practice and one example of local vernacular architecture. The results of these measurements are used both to evaluate the verification method based on measurements and extract lessons for sustainable building in the future. Life cycle analysis may be added to the analysis to draw further conclusions.
Point of view We only have one earth, but use an amount of resources corresponding to several in increasing parts of the world. Since the discovery of oil, we have in some parts of the world been able to live above our means, based on a finite amount of fossil energy. We are now experiencing the prize of this, in the form of global warming and increasing environmental problems. For a long time, the focus has been on creating renewable energy sources to solve this problem. This is however not enough; the development of renewable energy sources is too slow to replace the energy use of the worlds’ growing and increasingly energy-using population. Since this realization, the focus has shifted more and more towards energy efficiency. But energy efficiency is not enough either, since the saved Ingrid Allard Department of Applied Physics and Electronics Umeå University
energy (and money) often is used for other things instead and the total energy consumption stays the same. To really change our resource- and energy-use, a change in our values and lifestyles is also necessary. We need to adapt to the needs of the environment, not only adapt the environment to our needs, realizing that the needs of the environment in the extension are our needs as well. The level of economic growth for maximum well-being of the population has been passed a long time ago in most developed countries. By changing our definition of prosperity from economic growth to factors more up to date in describing the populations’ well-being, we could achieve a lower resource use and a higher quality of life at the same time. The values of our society also dictate how they are organized, which in turn dictates how much energy and resources it will use. For example: a selfsufficient society that uses local resources, whose infrastructure is built to facilitate life with a minimum of transportation, would result in very low energy use for transportation. Although this PhD-project is primarily about energy efficiency, energy sources and societal values are integrated parts of the vision for a sustainable built environment and can never be forgotten. I am also approaching the problem from the point of buildings in cold climate, specifically in the Nordic countries. Cold climates pose specific challenges for the built environment, of interest to me as a resident in a country with a cold climate. My vision of sustainable dwellings of the future also includes the possibility to live in close contact with nature, although this would not exclusively imply single family buildings, they have been chosen as the object of study the project since they are relatively easy to evaluate and have a long tradition in human history. The knowledge gained from them can also be transmitted to other types of buildings.
Ingrid Allard Department of Applied Physics and Electronics UmeĂĽ University