Australia’s heritage buildings present challenges and restrictions, but that’s no reason for them not to join the generation of smart buildings springing up across the landscape. Naturally, heritage projects still face many of the same challenges as non-heritage projects, such as cost vs ROI and long-term implementation, and heritage listing may make these goals harder to achieve. As heritage buildings can’t be built from scratch (unless only the façade or shell is being retained), retrofitting may be the only way forward. However, retrofitting any type of building is generally more cost-effective than rebuilding from the ground up, so retrofitting heritage structures can support a viable cost vs ROI model.
Heritage buildings tend to possess environmentally advantageous qualities because they were built to last and contain significant embodied energy. The Green Building Council of Australia (GBCA), the authority responsible for administering the internationally-recognised Green Star sustainability rating system, encourages reuse and retrofitting of existing buildings over new builds.
In terms of HVAC, heritage properties were generally built pre-A/C and therefore have intrinsic passive heating and cooling capabilities.
‘Heritage buildings are durable. They tend to be constructed of materials that can be repaired and recycled, and they have low recurrent embodied energy compared to newer buildings. Investment in the existing building stock reduces materials and energy consumption, emissions and waste’ (Judson & Iyer-Raniga).
For a smart building consultant, the main challenge to achieving a sustainable, efficient smart heritage property is how to implement modifications while maintaining the unique historical aspects and staying within the legal restrictions of the heritage charter. Straightforward, low-impact changes include monitoring gas, electricity and water consumption by fitting sensors to existing meters, as these meters are usually placed out of sight, in basements, cupboards or in external locations.
In many ways, sensors can benefit heritage properties more than standard buildings and create greater ROI by continuously monitoring the condition of the heritage aspects. Sensors could contribute to preserving the heritage materials, such as providing data on moisture in the air that could affect old timbers or preserving art and artefacts. The usual approach to smart buildings, mainly lighting and HVAC, could be tailored to the specific heritage requirements of the property. It’s a great theory but how would any of these visible modifications work in practice?
Let’s take lighting as an example. In Australia, the most commonly used proprietary protocol sensor systems are Signify’s Dynalite and Schneider’s C-Bus while the most popular open protocol is KNX. Each system has advantages and disadvantages in terms of its flexibility. The usual way to install a lighting sensor is to run a chasing for the cable, i.e. a 20-25mm channel recessed into the wall. Because heritage properties often do not permit the structure’s surfaces to be altered or damaged, the only option is to install sensors that sit on top of the wall or ceiling surface. Unfortunately, this type of lighting sensor cannot use recessed cabling and must be connected to existing power sources, which restricts the range of locations within the property where sensors can be used.
In addition to the cabling issue, installing a non-recessed sensor means the entire unit is visible. Non-embedded sensors tend to be larger, making them far more obtrusive than integrated sensor/relay units. In Europe, many designers are creating sensors and switches that are innovative and sympathetic to the aesthetic of heritage buildings, though at a cost. Such sensors can be difficult to obtain reliably from Australian distributors, are prohibitively expensive or take far too long to import.
An ideal solution to the cabling problem would be to install standalone battery-powered sensors. Units such as these are under development but have produced poor results, mainly due to lack of battery capacity and longevity. But the lack of chasing and the ability to attach and remove the unit easily without damaging the wall or ceiling is key.
Control systems can be a touchscreen that may often be wall-mounted but can be kept out of sight in a desk or behind a counter to limit the modern tech on view. The sensors can be painted in a colour that matches or is sympathetic to the surroundings.
Before the Heritage Council or governing body can approve retrofitting plans as heritage compliant, there’s still the question of connectivity. The insulating structure of historic properties, such as thick concrete walls or sandstone blocks, means that wireless signals may struggle to reach their intended destinations, particularly in dense inner-city hubs. Add in the fact that some rural heritage properties have limited connectivity options, and data transfer issues become a crucial part of the ‘smart heritage’ mix. Some sensors have functionality that can incorporate signal boosters but often the preferred locations of sensors must be altered, prior to the plans being approved, to ensure continuous connectivity.
Ultimately, when a heritage property owner or government organisation commissions an architect or smart building consultant to make a building ‘smart’, they can’t always achieve all the solutions they envisage, but the improved energy efficiency and the environmental and cultural benefits still far outweigh the negatives.
Judson, P. & Iyer-Raniga, U. ‘Reinterpreting the value of built heritage for sustainable development: Proceedings of the 2th International Conference on Heritage and Sustainable Development’. Green Lines Institute, Barcelona (2010): 535-545.
At mySmart we’ve been retrofitting heritage buildings with smart technology for more than a decade. Whether you’re looking to improve existing plans, or seeking guidance on futureproofing a heritage listed building, we’re an Australian company at the forefront of creating intelligent environments.
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