The Goldbeck construction system for multi-storey car parks saves over 22 Percent CO2
The fact that building with a system consumes less material than conventional construction is apparent at first glance: The prefabricated concrete elements are significantly more filigree compared to conventional solid construction - with identical functionality. But we wanted to know more precisely.
Who performs better in terms of the CO₂ balance: an MSCP built using conventional construction or construction using system elements? And what is the CO₂ balance over different life cycle phases? We have investigated this on the basis of a typical MSCP.
Question
How much CO₂ does a multi-storey car park from Goldbeck save compared to conventional steel skeleton construction with in-situ concrete ceilings and rolled section beams, taking into account production and disposal?
Conditions
A systematised car park concept already created by Goldbeck, which forms the basis for every car park offer, is closely examined in detail. This concept in our construction method is compared by calculation with the conventional construction method.The differences to the conventional construction are mainly in the shell construction. The focus is therefore on the Goldbeck precast concrete MSCP slabs (ramp and ceiling slabs) and the MSCP system beams (steel beams), which make up a significant part of the MSCP. Modules from the life cycle assessment of buildings according to DIN EN 15978-1 are analysed, which describe the expected life cycle of the entire building from the production of the raw materials to their recycling and disposal. Specifically, the material and energy flows from the extraction and processing of the raw materials (Module A1), the transport of the raw materials (Module A2) and the manufacture of the components from the raw materials (Module A3) are analysed. Modules C3 (waste processing for reuse, recycling and energy recovery) and C4 (disposal) are also analysed.
To ensure an independent and unbiased view, we then had the results of the internal study reviewed by independent experts from e-hoch-3 eco impact experts .
Test objects
The focus is on the systematised car park concept created by Goldbeck. Due to the systematised construction method, the concept is representative of all Goldbeck car parks.
The comparison building is a conventional multi-storey car park constructed with steel columns and in-situ concrete floors. The in-situ concrete floors are additive floors. In this construction method, a composite floor is made from trapezoidal sheets and in-situ concrete. The conventionally realised multi-storey car park was chosen at random and is freely accessible. Five full storeys (levels 0 to 4) were built on a base area of 40 by 40 metres. The primary data of the steel masses required for the construction of the supporting structure were determined during a site inspection. The slab was dimensioned with the help of Hoesch's general type approval for the Hoesch Additive1 in order to determine the required reinforcement and the necessary concrete thickness. The determined masses were compared with the masses of the components required for the designed Goldbeck car park.
The comparison of construction methods was based on CO2 benchmarks from the ÖKOBAUDAT platform – a platform of the Federal Ministry of Housing, Urban Development and Building (BMWSB). It provides a standardised database for the life cycle assessment of buildings. The respectivecarbon footprint was then calculated using GaBi – the standard software for such tasks – and in accordance with the life cycle assessment regulations of the German Sustainable Building Council (DGNB).
The GWP values (Global Warming Potential) of the Goldbeck car park ceiling and ramp slabs from the company's own environmental product declaration (declaration number: EPD-GOL-20240180-IBI1-EN), verified by the Institut Bauen und Umwelt, were also used in the comparison of construction methods.
The key data of the car parks in comparison:
Conventional car park Goldbeck car park
Area* 6.873 m2 6.680 m2
Number of full storeys 5 5
Ceiling slab material Reinforced concrete and Reinforced concrete
trapezoidal sheet metal
* The areas differ slightly from each other, as the car parks are bulit by Goldbeck according to a fixed grid.
Result
The differences are serious. The MSCP realized in the Goldbeck building system emits over 22 percent less CO₂ than the comparative object across manufacturing and disposal. This corresponds to a total of around 192 metric tons of CO₂ – almost 283 round-trip flights from Düsseldorf to Mallorca. Per square meter of net rrom area, this means a saving of around 26 kilograms of CO₂.
What are the reasons?
Our decades of experience in construction, the protected and at the same time modern production environment as well as series effects ensure continuous optimization of our components: We only produce what is actually statically necessary.
For example, our in-house produced welded cross-sections optimized for our use can save a considerable amount of material compared to rolled sections used in conventional construction. The eleven-meter welded cross-section is around 15 percent lighter than the corresponding rolled section. For the sixteen-meter welded cross-section, the weight saving is around 40 percent. The GOLDBECK MSCP ceiling slabs, with a thickness of around ten centimeters, are also on average more than 28 percent slimmer than those produced with in-situ concret.
This is also due – in addition to the continuous optimization of our construction performance – to the fact that with a special concrete formulation and in a protected industrial production environment, significantly less concrete is required to achieve the necessary load-bearing capacity. This also has an effect on the impermeability and corrosion protection of the slabs: the Goldbeck Multi-storey car park ceiling slabs do not require any additional coating.
Another advantage: Due to serial prefabrication Goldbeck's own factories, formwork required for casting reinforced concrete components are reused instead of remaining in the building as "lost formwork" after the end of the conventional construction phase.