By 2050, 60% of the energy needed for mechanical cooling could be saved using dynamic façade shading according to a new study by Guidehouse, commissioned by the European Solar Shading Organisation for the EU Commission.
Why do you come to work? What is the point of your company? A quick flick through the business strategies of the giants of our industry will tell you that building pretty buildings and making a profit is not remotely enough anymore. Indeed, they now define their very purpose through the prism of reducing carbon, in some cases competing to show that they are taking the most ambitious steps towards Net-Zero.
“We’ve made it our mission to reach net-zero carbon emissions by 2025 and ABSOLUTE zero by 2040. Our industry’s most aggressive targets. By far.” – LendLease, Mission Zero
“Our commitment to carbon neutrality guides our actions and our decisions at all levels of the organization” – Pierre-André de Chalendar, Saint Gobain
“Global emissions over the next few decades will shape our planet for centuries to come. As designers of the built environment, we have a vital role to play in both mitigating the impacts on these systems and enabling infrastructure and urban development to adapt to ongoing change.” – Alan Belfield, Arup Group
The trouble with Construction is that it involves making stuff, moving it around, and plugging it in; energy-intensive activities which result in our sector contributing a whopping 40% of the 51 billion tonnes of greenhouse gas we throw at our atmosphere each year. It is easy then to understand why the built environment and its supply chain featured heavily at COP 26 last month.
There is a misconception that all small steps towards resilience and sustainability will contribute to Net-Zero. But as Bill Gates articulated earlier this year in ‘How to Avoid a Climate Disaster’, 2030 is not necessarily a stop on the way to 2050. More radical ideas are required than simply replacing our coal-fired power stations with gas-fired ones that will still be in operation in 2050, regardless of whether India and China agree to it.
So, while we are waiting for the next generation of ‘carbon-free’ building materials and zero energy construction methods, which options should we be deploying now? Bill Gates’ answer is ‘the ones with a low Green Premium’. Technologies that already exist and are compatible with a net-zero long-term future.
One such ‘low green premium’ option is dynamic, automated facade shading; and a new study from Guidehouse, commissioned for the EU, has revealed some astonishing results on the impact this existing technology can have on energy use in buildings over the next 30 years.
Can Europe kick the A/C habit before it takes hold?
Europe is getting hotter. According to the Intergovernmental Panel on Climate Change, between now and 2050 the average number of days per year our continent will require A/C for will increase by around 30%. A report from the International Energy Agency estimates that A/C installations will increase from 115 million in 2020 to 275 million in 2050. However, the Guidehouse study sets out a way to escape these depressing projections.
The Guidehouse Study
The study takes established baseline data and projections for present and future emissions from A/C across Europe, defined as “Business As Usual” (BAU), and compares it with potential emissions in a moderate scenario where dynamic solar shading is properly recognised through EU regulations and implemented more widely, but still fairly cautiously, in the construction industry, defined as “Preferred Implementation”.
Even for this adjusted, moderate scenario, the results are quite striking. In the BAU scenario, 45% of buildings in Europe will require A/C by 2050, compared with 28% today. In the Preferred scenario where dynamic facade shading is implemented effectively, that number could remain static. In terms of energy consumption, that equates to a saving of 56 Terawatt hours per year, or 58% less greenhouse gas emissions.
“In Europe today, 100 million people are not able to keep their homes cool in summer. That is twice as many as those who cannot keep their homes warm in winter” – Peter Winters, ES-SO / Dickson Constant
Show me the money
What will it cost to make this change? The study explored the cost of implementing more dynamic solar shading and found that up front capital expenditure is broadly cost-neutral when compared with the equivalent requirement for A/C installation. On top of this, very significant savings will be made from ongoing operational costs. The conclusion is that switching from more A/C to dynamic solar shading systems could save some €14.6 billion across Europe every year.
“Optimized uptake of dynamic shading is highly cost-efficient. The additional CAPEX for Shading is over-compensated by the less CAPEX for AC resulting in an estimated saving of bill €14.6/year.”
Performance or Compliance?
“If we’re not deploying these solutions already, it’s a sign that cost isn’t the barrier. Something else – like outdated public policies or lack of awareness – is stopping us from getting them out there in a big way” – Bill Gates, How to Avoid a Climate Disaster (2021).
If the impact of solar shading is so great, why are these benefits not already being realised today? One reason in Europe at least is that façade engineers and other members of our design teams are forced to use out-of-date simulation software in order to comply with outdated regulations. Most of this software is based on an old platform originally designed to plan HVAC, and not capable of modelling the real combined energy performance of glazing and shading. This combined with wider regulations make it challenging for design teams to do anything other than resort to Air Conditioning to tick the compliance box, leading to missed opportunities in façade performance specifications and ultimately higher running costs for clients.
A recent study looking at the difference in building performance between Europe and Australia found that on average, new prime offices across Europe may be using twice as much energy per m2 for base building services as their Australian counterparts. The report concluded that there are no intrinsic physical reasons why new offices in Europe cannot perform as well as Australia’s, but that in the EU, base building energy in use is neither measured nor targeted; the design of energy efficient offices is rarely informed by feedback from real world measurements; and a design-for compliance culture, lack of energy performance disclosure, and confused responsibilities have contributed to the EU falling behind.
Case Study: One Sydney Harbour
The final piece in the puzzle of Lend Lease’s award-winning, carbon-neutral project Barangaroo South, One Sydney Harbour comprises three towers with the tallest rising to 250m. Natural ventilation, access to natural light, the use of photovoltaic cells and the design of high-performance double-skin façades including integrated dynamic solar shading control the internal environment, reduce energy consumption and provide a high quality of life for the residents.
More than 5,000 tensioned blinds are integrated into the façade and play an important role in achieving many design and client objectives. A combined g-value of 0.37 for glazing making up the inner and outer skin of the façade is reduced to 0.11 with the blinds deployed, thanks to the combination of a bespoke metallised fabric and low-iron glass. The blinds are controlled by a ‘CRE Zone Intelligence’ system which communicates over IP and employs AI software to optimise blind movement to suit both energy efficiency and user preference. The project is designed to exceed a 5-star NABERS rating.
Architect: Renzo Piano
Developer: Lend Lease
Façade Engineer: Arup Façade
Integrated Façade Shading: Climate Ready Engineering & Guthrie Douglas
Case Study: The BD Building, Gothenburg, Sweden
A Hall – “During my past years in Project Sales this project was, back in 2010, the very first using a true holistic approach in regards of the early-stage cooperation amongst all key players. We discussed the shading solution almost 1 year before they even started the digging on site. This was not only completely new to me but also one of the most pleasant projects I ever made due to the mutual engagement and respect that characterized the process. The result is a building, with 65% glazed facades, automated external blinds all over and internal screen blinds for personal use and potential glare adjustments.
Combined with all other technical functions installed the building is using approx. 40 kWh/m2 year (building energy) making it one of the most energy-efficient offices in Sweden still today.”
Reasons to be Cheerful
There are already some promising signs that the UK construction industry might be about to sit up and smell the Australian-ground coffee. The NABERS system that has proven successful down under in measuring actual energy use of offices and allowing clients to accurately track and communicate the energy performance of their buildings is being introduced in the UK through BRE and the Better Buildings Partnership.
New energy modelling software such as ESBO (Early-Stage Building Optimization) and IDA ICE, which can more accurately model the combination of shading and glazing based on ISO Standards, EN norms and spectrally measured performance data, are slowly gaining traction in the market.
These developments represent potential long term, structural changes which in combination with the significant work being carried out across the industry on embodied carbon and energy savings could play a key role in our response to the climate crisis and drastically change how we think about our buildings and their carbon footprint.
That old chestnut – Collaboration
“If working apart we are forces powerful enough to destabilise our planet, surely working together we are powerful enough to save it.” – Sir David Attenborough, COP 26 Speech, Glasgow 2021.
Turning the benefits into reality means automatic blind control. Solar modelling and live radiation data can be balanced with local overrides for individuals. Addressable digital motors running over native IP networks can speak multiple languages including KNX, BACnet & MQTT, resulting in flexible integration with the BMS via fewer cables.
New open protocol AI and IoT based software makes almost any configuration possible and enables remote monitoring for ongoing maintenance. Blinds, lights and HVAC units can talk to each other, predict individual human needs, respond autonomously and re-set themselves for aesthetic uniformity and energy requirements.
“Using sunlight and daylight is like trying to drink from a fire hydrant: the challenge is CONTROL” – Prof Stephen Selkowitz, Lawrence Berkley NationalLaboratory
However, the only way to get this all right is proper collaboration between specifiers, engineers, and product manufacturers early in the design process. In most cases, this is still not happening. Reliance is often placed on building services engineers in the unrealistic expectation that they should somehow know it all. However, there are a growing number of more holistic ‘Environmental Design Consultants as well as integration and controls experts operating within the larger, multi-disciplinary facade engineering practices who do have the potential to take on what Eckersley O’Callaghan term a ‘Specialist Generalist’ role, facilitating genuine early collaboration.
Those that do this successfully will lead the charge in delivering buildings that truly harness the power of light and shade as positive environmental and architectural features, rather than creating problems to be overcome later.
The conclusions of the Guidehouse report are that an uptake in dynamic façade shading over the coming years will:
- Stop overheating in buildings
- Massively reduce electricity use from Air Conditioning
- Significantly reduce greenhouse gas emissions
The report is likely to influence future EU and UK regulations to stipulate that active air-conditioning should only be considered after dynamic solar shading is applied, a step which would necessitate much-needed change in knock-on areas such as façade performance modelling software. Automated blinds are not revolutionary. Bring on the net zero electric cars, zero-carbon cement, organic facades, coolants that don’t contain F-gases and getting to know one another as avatars in Mark Zuckerberg’s metaverse from the comfort of our sustainably sourced sofas. While we are waiting for all of that, the combination of clear glass and integrated dynamic shading, executed effectively through collaboration in façade design, can be a game-changer for environmental and economic building performance.
- Intergovernmental Panel on Climate Change: https:// www.ipcc.ch/site/assets/uploads/2018/03/sres-en.pdf
- Design for Performance not compliance: making measured energy in-use the objective for new office buildings. Robert Cohen, Paul Bannister and Bill Bordass, Verco, Energy Action Australia, Usable Buildings Trust.
- Synergising mitigation of GHG emissions and adaptation to climate change. The potential to disrupt rising cooling demand and overheating in European buildings”, Guidehouse Germany GmbH, 5 November 2021
Guthrie Douglas are a team of specialist engineers with the sole focus of creating technical shading systems for extraordinary spaces. We collaborate with designers who share our love of inspirational and sustainable architecture. www.guthriedouglas.com
ES-SO represents professional solar shading associations from across Europe, which account for some 450,000 employees and a market size of more than €22 billion. We operate on a not-for-profit basis and seek to enable our members bringing a positive contribution towards the ambitious energy efficiency and resilience commitments made by Europe today. www.es-so.com