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ABRACADABRA project: Building add-ons are a solution to low construction rates

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by Ralf Tinga (PRACSIS)



BUILD UP attended the third international workshop of ABRACADABRA, a project that encourages the development of building add-ons with integrated renewables. Building add-ons could be a solution to today’s low construction rates, but regulations are hampering their roll-out.



The name of the project, ABRACADABRA, refers to the acronym ‘Assistant Buildings' addition to Retrofit, Adopt, Cure And Develop the Actual Buildings up to zeRo energy, Activating a market for deep renovation’. In other words, the project encourages the roll-out of building extensions and building add-ons.


Building add-ons are additions to the top, sides or façades of buildings. They offer extra living space, additional units or can even be entirely new constructions. When they integrate renewable energy, they’re referred to as ‘AdoRes’ (See Image 1).


Building add-ons might be a solution to current low construction rates, where new buildings only increase the building stock by 1 to 1.7 % per year. At the same time, building add-ons increase architectural and real-estate values, which can counterbalance the investments needed for the deep renovation of an existing building.





ABRACADABRA’s third international workshop concentrates on the regulatory barriers that hamper the market for add-ons. Companies that construct building extensions face local, national and European regulations on a wide array of themes: urban planning, construction, energy efficiency, water, land use, soil; and even on construction in areas with seismic activity. ‘We need less regulation and more flexibility,’ says project coordinator Annarita Ferrante, ‘we almost need a legislative revolution.’


Enormous differences between the EU Member States pose another challenge. Some countries do have regulations, for example permitting building extensions of up to 30 % of a building’s surface area. Others entirely lack rules. ‘We’re dealing with extremes here,’ explains Michele Zuin of project partner ICLEI.





ABRACADABRA gives special attention to densification, urban sprawl and soil sealing. By doing so, it adheres to current environmental priorities like climate adaptation and the protection of urban permeable surfaces. The European — now international — Covenant of Mayors initiative embraced climate adaptation in 2016.


Green roofs are one of the project’s answers to the loss of land and permeable soils in cities. ‘It is possible to construct add-ons, while at the same time increasing the amount of green and permeable surface,’ says coordinator Ferrante.