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ONLINE BRUSSELS HERITAGE - ONE-DAY SEMINAR - 11/12/2014
Significantly, interventions in an old building can be more expensive than in a “regular” building. For example: in one of the two homes the façade insulation costs between EUR 400-500 /m2, while in a classic building the cost ranges from about EUR 100-150. Different improvement priorities were applied for each building as well as for each scenario: scenario 1 was the purely theoretical value; scenario 2 was the revised theoretical value, which is closer to the actual value for energy consumption.
The heating in the Ibissenstraat home was the last priority because it had a good boiler but the roof was not insulated. The priorities were thus firstly insulating the roof, then the building shell and, somewhere in the middle, the windows. The return on investment times in scenario 1 is three years for the roof and 90 years for the façades. But scenario 2 gives 300 years for the façades’ return on investment time; for this reason this measure was not applied.
Conversely, in the Kruisbooglaan home heating was the priority - the house had an old boiler situated outside the protected volume in the cellar. Replacing this was prioritised. A similar list then follows, with the façades again at the very end. Scenario 1 gives us 60 years if we take the longest return on investment time; that becomes 166 years when a more realistic existing energy consumption is applied.
The full audit is available on the website of the Direction des Monuments et des Sites:
Translated from Dutch.
Final energy use - Ibissenstraat 5
Fig. 7
Savings Ibissenstraat 5. Primary energy consumption (© Cenergie).
Final energy use - Kruisbooglaan 34
Fig. 8
Savings Kruisbooglaan 34. Primary energy consumption (© Cenergie).
52 | Financial impact of energy efficiency measures in Le Logis and Floréal
