In dense urban living, the ability to connect with the outdoors for enjoyment and for wellbeing becomes starkly important. This became particularly apparent in the COVID-19 pandemic when millions of people across the globe had to be confined to their homes for long periods. Notwithstanding that, as the world increasingly urbanizes, good quality housing design is vital and this includes access to the outside. In a city like London, this need was recognized, and providing an outside space in every dwelling became mandatory around the year 2010. In multi-storey housing, providing outside space usually takes the form of a balcony. The design possibilities are endless, so what are the key considerations when incorporating balconies in an urban residential building?
Various Uses of The Balcony
The first consideration is use. While this can vary between regions and cultures, some basic opportunities are afforded by balconies. Primarily, this is the ability to be outside while being at home – simple enjoyment of the fresh air, sunshine, or the elements. Being outside enables a connection with the street below and even communication with neighbors. Activities on the balcony include lounging, socializing, dining, and even gardening, where the balcony can be a place for growing food or inviting bees and wildlife. There are also practical benefits such as being able to hang washing outside or store bulky outdoor belongings such as bicycles. A successful balcony design should cater to a variety of uses.
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Projecting or Recessed Formats
In its broadest definition, a balcony can take many formats. The most typical is the projecting balcony. This sits entirely outside of the façade line and is regarded as the most exposed to the elements as well as the most connected to the environment, being open on three sides. It is most suitable on storeys closer to the ground where the wind is not a problem. Another format is the recessed balcony, which sits entirely within the façade line of the building and is only open on one side. This is the least exposed format and can work on any level including the upper storeys of tall buildings. Although it has less of a connection with the outside, it has the benefit of feeling like a sheltered ‘outdoor room’.
In between these two formats is the semi-recessed balcony. If designed well, this could provide the best of both worlds, but it can also result in unnecessarily complicated detailing. A fourth format, which can be projected or recessed, is the winter garden. This is a balcony enclosed in openable glazing and is particularly suitable in cold climates when facing a noisy environment such as a busy road, and/or on the upper storeys of tall buildings. Finally, in cases where balconies of any type prove unfeasible, a Juliette balcony can be used instead. With large patio doors and balustrades, it is not strictly a balcony, but it can open up the interior space to achieve a connection to the outside.
Accessing the Outside Space
A successful balcony is easy to access by all members of the household. If there is only one balcony, it should be accessed from the living area or any other shared space. A level threshold ensures those with mobility impairment or using a wheelchair can also enjoy going outside. The doors to the balcony need to be considered. Outward-opening doors benefit the internal layout but can take space from the balcony, and vice versa for inward-opening ones. Sliding doors can help with this.
Maintaining Privacy
Although an outdoor space, a balcony should provide a minimum level of privacy. This level will vary between cultures, but the architectural tools to achieve it are similar. Distance between balconies on the same building or nearby buildings is a significant factor in the sense of privacy. Proximate balconies or balconies that share a structure can be subdivided using walls or privacy screens, whilst balconies that are close to street level can benefit from solid balustrades.
Balconies and Building Composition
Balconies are a major component of a building which has them, and they are an integral tool in the composition of the form and the environmental design of the building. For example, projecting balconies on the south façade can contribute to shading (in the northern hemisphere), and recessed balconies can create deep, cool interiors where that is desired. Where internal daylight is scarce, however, balconies should be designed to maximize daylight entering the building.
Stacked balconies offer shelter to one another and offer better privacy. Staggered balconies can result in playful facades and better internal daylight, but privacy can be compromised and they are less sheltered. Streets in historic urban centers may require buildings to have formal facades, favoring recessed balconies.
Types of Structure
Aside from the functional, environmental, and aesthetic considerations of the balcony, there are also technical considerations. A projecting balcony will typically cantilever from the main structure and can be constructed out of steel or reinforced concrete. Those constructed of aluminium can offer a lightweight option with less impact on the main structure, and can even be part of a modular façade system as opposed to being fixed directly to the primary building structure. Larger balconies, or where the primary structure is not suitable for a cantilevered balcony, may necessitate balconies propped with external columns or posts. Recessed balconies can be simpler structurally as they are supported on three sides.
Interfacing with the Building's Thermal Line
Where the building has insulated external walls, the balcony structure must be thermally isolated. This is to avoid a cold bridge which weakens the thermal performance of the building fabric and can introduce a risk of condensation. Structural thermal connectors can provide a continuity of structure while maintaining thermal isolation. Where very high thermal performance is required, a freestanding and wholly separated balcony structure may be required.
Design of Balustrading
Balcony balustrading can take many forms, such as metal railings, solid panels, or glass. As well as privacy considerations mentioned above, railings must be of sufficient height for safety and be able to withstand a minimum force. Designing with children in mind, balustrades must avoid gaps that can be head traps and must not be climbable. Glass balustrades have further requirements related to the integrity of the material and avoidance of spontaneous failure.
Management of Rainwater
Rainwater on balconies should be managed adequately. Where balconies are stacked and share a single rainwater pipe, special gulleys are used to avoid blockages affecting the shared pipe. For small balconies, water can simply be shed away from the façade, or the balcony floor can be left porous so rainwater freely drains away. Whichever the arrangement, water should be encouraged away from the façade and the door threshold.
Designing for Safety
Further safety considerations include the types of materials used. Depending on the height of the building and the local codes, combustible materials may not be used on balconies. Floors should be robust and non-slippery when wet, and balustrades should not encourage the placement of objects that could fall on passersby below.
Whilst building codes and cultural expectations will differ from place to place, the above guide is intended to pinpoint aspects of the design of balconies to consider when incorporating them into the design of a building. The exact requirements will depend on the applicable codes and regulations.
This article is part of the ArchDaily Topics: Outdoors and the Built Environment. Every month we explore a topic in-depth through articles, interviews, news, and architecture projects. We invite you to learn more about our ArchDaily Topics. And, as always, at ArchDaily we welcome the contributions of our readers; if you want to submit an article or project, contact us.
