Multi-story developments are a common sight in most major towns and cities across the UK, fuelled by the demand for affordable residential housing, high-quality student accommodation and versatile office space. As fenestration design is one of the most important elements of the building envelope, Andrew Cooper, national specification manager from Senior Architectural Systems looks at some of the key points to consider in terms of safety, sustainability and style.
A tall order?
One of the greatest challenges faced by all tall buildings is also one of nature’s greatest forces – the wind. Exposure to wind loads, particularly at height, can create issues with structural movement and literally make or break the success of a scheme but fortunately, the correct specification of fenestration systems can help to mitigate any potential problems. Aluminium systems, thanks to their inherent strength and ability to be powder-coated to provide additional protection against weathering, are the ideal choice and working closely with the product manufacturer is a great way to reduce risk and identify the most effective package.
Safe solutions
Careful consideration also needs to be given the opening styles of windows as those that open outwards are neither safe nor practical for high-rise schemes. Tilt and turn aluminium windows are a popular choice as they combine the look of a traditional casement window with a modern opening style that can be operated in two ways – they can be used in the tilt position for ventilation, with the turn function used for ease of cleaning from the inside. The tilt feature also provides ventilation with restricted access to prevent people, children in particular, from climbing or falling out.
Parallel push style windows are also a great solution. With hinges on all sides of the frame, this type of window can be easily pushed open and yet will remain parallel to the wall. This enables rooms to be safely ventilated, with the limited opening helping to reduce the risk of falls from the window or trapped fingers. Aesthetically, the use of push parallel style windows can also help to create a more uniform façade.
Depending on the specific scheme, another option could be use of window restrictors which provide protection from falls but still allow windows to be opened for ventilation. Additionally, the installation of external mesh panels, used in conjunction with opening-in windows, can improve safety. These panels can also incorporate bespoke and aesthetically pleasing design details, bringing another dimension to the architectural impact of the building façade.
Maintaining a good impression
Although safety will always be the top priority, the specific style of chosen window system will also depend on what cleaning procedures are in place. Most high-rise developments will utilise external glazing cleaning contractors which will access the façade via the use of specialist equipment and so this will make the use of fixed light windows and large areas of curtain walling more appropriate.
If an internal strategy is preferred or access to the external façade is difficult, cleaning and maintenance must be able to be achieved safely. One option is to specify overswing style windows, which are fully reversable and enable the outside of the glass and frame to be safely cleaned from the inside.
As well as offering a wide range of design options, the high durability of aluminium window systems can also help extend maintenance cycles as they are quite simply, very easy to maintain, with many offering a life cycle of upwards of 40 years.
Unlocking style potential
Increasingly, many high-rise residential developments include balcony access and here, aluminium sliding or bi-folding doors can be extremely effective. Offering slim sightlines which maximise the use of daylighting, aluminium patio doors can transform even the smallest of spaces. Choosing complementary doors and windows from the same supplier can also help reduce risk and create a more co-ordinated design. The combination of aluminium doors windows and curtain walling also a great way to frame one of a high-rise scheme’s biggest assets – the far-reaching views they offer.
Sustainable solutions
As well as the overall design and its location, the environmental credentials of a scheme are incredibly important, as is demonstrating to increasingly environmentally conscious residents how the building can allow them to save both money and reduce their carbon footprint. Thermally-efficient fenestration systems play a vital role in creating interior environments that are not only comfortable but cost-effective to run, by helping to retain heat and reducing reliance on central heating. By achieving exceptional low U-values, the correct specification of aluminium fenestration systems can also contribute towards meeting top BREEAM targets and assist with meeting planning requirements.
Thermally-efficient windows can also significantly reduce the risk of condensation build up which can be a common problem in high-rise apartment buildings, particularly in student accommodation, where laundry may be dried indoors and kitchen and bathrooms are in close proximity.
Bespoke approach
There are many challenges of ‘working at height’ and many more issues that individual developers will face. In these uncertain times, collaborating closely with suppliers will unlock valuable expertise and experience and help to provide a clearer view on specifying a fenestration package that performs well on many different levels.