Case study – 1989 built single family house in Espoo
Heating demand reduced by 35% (from 80 kWh/m2 – 50kWh/m2)
Changes made: Attic insulation increased, Ventilation modernized, Programmable floor thermostats installed, Doors renewed, Radiator heat reflectors installed, Section of wall insulated
Case study – Early 1900 apartment in Berlin
Energy diagnosis conducted – Possibility to reduce thermal conduction by 50%
Double paned windows covered 40% of the wall area. Upgrading the windows to vaccuum glazed would reduce thermal conduction by 50%
Case study – Early 1900 single family house in Porvoo
Energy diagnosis conducted
Heating demand calculated using table values: 30 000 kWh/y
Heating demand calculated using element composition: 10 000 kWh/y
Heating demand calculated using measured U-values: 20 000 kWh/y
True heating demand: 20 000 kWh/y
Space heating creates significant demand of energy and upon exceptionally but annually found cold weather periods problematic peaks for energy supply. These peaks could easily be reduced by proper insulation but the success of thermal refurbishments has been modest despite generous subsidies in various European countries. It is well known that the savings upon thermal refurbishment tend to be far less than predicted. Key issue is to know the situation prior to refurbishment as it will allow precise calculations of savings with tailored improvements of added insulation performance of solid walls, ceilings and windows. Knowledge for decision making and case studies have been highlighted to be the most important issues required to catalyze thermal refurbishments (EEFIG report 2015).
By now the main reasons for failure in estimating insulation performance and required changes are due to 2 simple issues: insulation performance and respective U-values can’t be calculated reliably (according to a recent study by BRE in UK) and user behavior creates another uncertainty (±40%). Therefore there are 2 unknown parameters and thus preventing overall diagnosis of energy demand and losses.
The graph below shows the correspondance of estimated values compared to the actual U-values.
This set of data is from UK but presumably building walls in other European countries are equally well built and documented…
A completely new innovation from Arcada for rapid U-value metering is ground breaking as it will allow precise measurement of U-values of various parts of building envelopes. During normal working day an expert can measure more than 60 single values and thus create precise and most valuable map of heat losses for almost any building. Associated measurement principle and service concept have also been developed. Utilization of energy diagnosis data allows also quantification of the influence of user behaviour.
By measuring the actual U-values one can do quality checks of new and refurbished buildings. Also, by knowing the insulation performance before planning any thermal renovations, the amount of additional insulation can be calculated easily. Too much insulation is a waste of money, but too little is a lost opportunity. One could call this “precision insulating”, the most cost efficient way to make renovations.
Current Issues and Legislation
Research consultancy BRE has carried out in-situ measurements of wall U-values in approximately 300 domestic dwellings in England, together with more detailed investigations in a subsample of those walls. This image is a comparison between measured U-values and calculated U-values for various types of brick walls.
Questions exist around the assumptions used when predicting savings from solid wall insulation. In particular there is a gap between calculated predictions and actual realised energy savings following the application of this measure. Providing better estimates of solid wall insulation savings
BRE also conducted a review of the literature on solid wall heat losses and the potential for energy savings in the summer and autumn of 2013, completed on 29 November 2013.
The Society for the Protection of Ancient Buildings Research U-value Report sets out the findings out of research work carried out into the subject of the heat loss (U-values) of traditionally-built walls.
The 2012 Energy Efficiency Directive (EED) establishes a set of binding measures to help the EU reach its 20% energy efficiency target by 2020. Under the Directive, all EU countries are required to use energy more efficiently at all stages of the energy chain from its production to its final consumption.
EU countries were required to transpose the Directive’s provisions into their national laws by 5 June 2014.
Energy Efficiency Directive
The Directorate-General for Energy is one of 33 policy-specific departments in the European Commission. It focuses on developing and implementing the EU’s energy policy – secure, sustainable, and competitive energy for Europe, creating a competitive internal energy market to lower prices, to develop renewable energy sources, to reduce energy dependence and to reduce energy consumption.
EU energy legislation, 2010 EU Directive 27, 2012 EU Directive 31
The European Commission oversees that EU countries fully and correctly apply EU energy law. When a country fails to do so, the Commission may take legal action by launching an infringement procedure and eventually referring the case to the Court of Justice of the European Union for a ruling.
Latest Commission decisions on energy infringements
Demands of the future
At the Paris climate conference (COP21) in December 2015, 195 countries adopted the first-ever universal, legally binding global climate deal. The agreement sets out a global action plan to put the world on track to avoid dangerous climate change by limiting global warming to well below 2°C.
The agreement is due to enter into force in 2020.
EU vision for the Paris Protocol
The European Commission is looking at cost-efficient ways to make the European economy more climate-friendly and less energy-consuming. Its low-carbon economy roadmap suggests that the EU should cut emissions to 40% by 2030 and 60% by 2040, and 80% below 1990 levels by 2050. The EC states that if all sectors contribute, the low-carbon transition is feasible & affordable.
EC climate strategies and targets, EC 2050 low-carbon economy
The Energy Efficiency Directive places energy savings requirements on EU countries’ buildings. This includes making central government buildings more energy efficient and requiring EU countries to establish national plans for renovating overall building stock.
EU countries have drawn up strategies to show how they plan to foster investment into the renovation of residential and commercial buildings. These strategies are part of their National Energy Efficiency Action Plans. They provide an overview of the country’s national building stock, identify key policies that the country intends to use to stimulate renovations and provide an estimate of the expected energy savings that will result from renovations.
National building renovation strategies