The renovation of existing housing is essential for reducing energy consumption, but is often done without the necessary thought and planning. Doctoral candidate Thaleia Konstantinou has developed a Façade Refurbishment Toolbox that enables architects to plan a strategy for renovation at an early stage.

The Façade Refurbishment Toolbox (FRT) allows users to enter data about the construction, orientation, type of façade and use. Once the data entered has been compared, advice is issued that provides a clear picture of the options for conserving energy. “This enables designers to clearly identify potential opportunities from the outset, helping them to make well-founded choices”, explains Konstantinou. The result can also serve useful in negotiations with the building owner. For example, the toolbox provides information about the payback period.

It is hoped this aid in renovating the building envelope will boost efforts to achieve the ambitious European targets for energy and CO2 reduction. Housing accounts for a quarter of all energy consumption, on which the EU intends to make 60% savings in the upcoming decades.  The greatest gains can be achieved by renovating building façades and this is what the FRT has been specifically designed for.

Konstantinou's research focuses primarily on integrating all aspects of energy efficiency at an early stage in the design phase. Since much of the designer's work involves creating an attractive design and managing costs, a quick overview of all energy aspects is particularly useful at this time. This is because early design decisions are instrumental in determining the ultimate costs. In order to validate and enhance her method, the Greek doctoral candidate interviewed numerous architects, students and developers and conducted simulations.

Entering the relevant data takes about an hour and results in a systematic assessment of the options. First of all, the necessary façade components and adaptations are determined. The potential energy improvement is calculated based on this. This data is then used to generate a roadmap for carrying out the renovation.

As a result, the designer gains an early and straightforward insight into the U-values (thermal transmittance) for the existing façade construction, together with the various insulation materials and glazing that can be used to improve these values. Is it worthwhile insulating an existing concrete balcony slab? Or would it be better to remove it completely, thereby eliminating the enormous cold bridge? For each floor layer, it also provides details of the percentage of energy reduction that is possible if the layer above it or the roof is insulated.

Because the calculations are always based on a series of assumptions, there is a margin of uncertainty. “Despite that, the percentages turn out to be relatively accurate when calculated retrospectively. Greater precision can be achieved at a later stage, during implementation”, says Konstantinou. “What matters most is that you have concrete information about potential energy savings at the start of the renovation process. You can use this to motivate and inspire the owner of the building.”

Published: September 2014