Outdoor living is becoming more and more popular, and in the cities roof terraces and balconies are in high demand – and the larger the better! The example above is the Harbour Tower in Copenhagen, with gallery-type balconies for all apartments.
In our previous posts we have focused mostly on subjects like material properties, engineering challenges, architectural opportunities, and day-to-day practical issues such as repairs and installation methods.
We recently realized that we have not taken the time to look at UHPC balconies from the perspective of the most important people, namely the users!
This we will correct now, with a mini-series on the balcony experience, showing the significance of the balcony features of the three main types (as seen from the user): Plate balconies, Balconies with parapets and/or privacy screens, and box balconies (with sides and roof, and potentially enclosed with glass).
This first post in the series will focus on the plate balconies.
The definition of a “plate balcony”
Plate balconies are defined by not having integrated parapets etc. – It is basically a slab with a light fence to look at.
It can be constructed in many ways: Cantilevered, or supported by a combination of brackets, columns, frames, struts etc., however irrespectively of the static principle used, the precast concrete element is “just” a plate, and the experience of the user is the same.
The main reason for using CRC i2® for plate balconies is the opportunity to increase the size with acceptable loads and small cold bridges towards the remaining structure.
The look and experience however can vary a lot.
The gallery
The first image showing The Free Harbour Tower is an example of the plate balcony in the style of a continuous gallery – but as private balconies instead of access ways. This provides a lot of outdoor space but is a rather luxurious solution – the equivalent of a patio for high rise buildings.
The more normal way to use galleries is to use them for access, and If possible combined with space for recreational purposes:
CRC i2® galleries in Copenhagen (left) and Aalborg (right). The project on the left has a very limited width, and consequently cannot be used well for other purposes than access, whereas the project on the right with app. 2 m wide galleries allow tenants to sit outside with room to spare for passing neighbours.
Balconies – Size matters!
To the user, balconies smaller than app. 1.5 meter are depth is difficult to use – furniture will prevent people from moving around, and the feeling can become a little claustrophobic. In that size range, even a 10 cm difference in depth can make a huge difference.
The opposite is very large balconies – as in the image below from Norway, Kjøita – where the balconies are large enough to accommodate even couches and lounge chairs.
Very large CRC i2® balconies at the Kjøita Secret Garden residential complex in Kristiansand. The large 3.5-meter deep, and up to 5 meter wide balconies leave ample space for luxurious outdoor living.
Notice also the wooden decks – this is becoming popular on plate balconies as it gives the impression of a traditional terrace or patio, but underneath is an elaborate detailing of inclinations and drainage canals to remove the water. Use of UHPC makes it possible to make this detailing in a limited space, and with a limited weight, despite the size.
CRC i2® balcony during installation of the deck planking at Kjøita Secret Garden in Kristiansand.
Combining galleries and balconies
When a general depth of several meters is too expensive or complicated, an alternative is to use a general depth corresponding to a gallery (allowing passage) and then extent sections further to create larger spaces for outdoor living.
The principle is illustrated in the two examples below from Holland, more images are available, Woontoren de Verkenner and Huize het Oosten.
This opportunity is unique to the plate balconies, (no parapets to block passage), and provides a very open and inviting outdoor space.
CRC i2® balconies with a combination of “gallery sections* between the “balconies” on the two Dutch projects Woontoren de Verkenner (left) and Huize het oosten (right).
To summarize, the experience of the outdoor room provided by plate balconies is to a large extent defined by available space – there must be room to move around, otherwise the space will not be used much.
This trend towards larger balconies and outdoor living spaces in general is ideal for UHPC and the larger sizes possible due to the lower weight – we therefore invite you to think big when considering balconies!
This was the first chapter in the mini series on the balcony experience. I hope you found it interesting and we look forward to sharing more examples in the next posts.
Thank you for reading the post, feel free to leave a comment and questions below.
Tommy Bæk Hansen
Group Product Development Manager
+45 40 64 37 20
tbh@hi-con.dk