Energywise renovation
When a house is renovated it is wise to improve its energy efficiency at the same time. It is profitable to up-grade energy-efficiency to the house whenever renovation (roof, external walls, foundations, floor) is needed. Adding energy-efficiency is the only aspect of renovation that will pay itself back with interest!It is obvious that a building, which is built according to the minimum standards of new heath insulation regulations is not going to be seen as an energy efficient building in year 2020. The European Commission has discussed a requirement that would require all new buildings to have the same energy efficiency level than Passive Houses from year 2015. This gives a clear impression of the radical tightening of energy efficiency regulations in the future.
Therefore it is wise to be well-prepared for the future energy efficiency requirements already now, when designing a new building or renovating an existing house. As each house is unique, each energy renovation project must be carefully planned according to the specific needs of the house.
Energy Optimized Renovations*
Paroc will publish instructions and design guidelines for the Energy Optimized Renovations on this website by the end of 2008. In the Energy Optimized Renovation each building component is optimally upgraded or replaced using the best available technology to bring the energy efficiency of a house to the passive level. The tightening energy efficiency requirements of the future will be taken into account in these guidelines
Notable potential
From the energy conservation point of view, renovation of the existing building stock represents by far the largest potential in the building sector. But at the same time, from the technical point of view, it represents the most demanding challenge. It is not feasible to bring the energy efficiency of an existing building up to date to the level of a passive building in a “normal” way. In most cases it would not make sense in terms of economics.
Component approach
Instead of renovating an existing building in a single operation, so called energy optimized renovation is recommended. The economics of the process is optimized by looking at the repair of the building as a sequence of component based projects throughout the life of the building. Each component e.g. the façade, windows, roof or the HVAC system are upgraded or replaced at an optimum point after the service life has come to an end. Each time a component undergoes renovation, the best available technology is being used to bring the energy efficiency to the passive level.
Careful planning is called for
The energy efficiency of a building is more that just the sum of its components. Components interact and therefore it is vital to look at the building as whole. Let us take an example. Old windows equipped with air inlets in the frames are replaced with modern highly energy efficient windows which do not have any air inlets. Fresh air is taken in through the heat recovery unit, and the HVAC system has to be modified correspondingly. This illustrates that a change of a component might have an impact to another. Therefore careful planning is necessary in order to avoid mistakes.
Life cycle approach
Through the years of several component based renovation schemes, the energy efficiency of an existing building is upgraded, in an economically feasible way, to the passive level. At the same time the life span of the building is extended in a sustainable way.
*Pekka Haikonen, Development Manager, Paroc, 11 March 2008.