The Future of Glass Skyscrapers

Recent headlines internationally have seen a call to ‘Ban Glass Skyscrapers’ with this in mind; and the evolving Climate Emergency that has been declared, we as architects cannot deny the impact we make on the environment through our works.

Following the Strike for climate change, it is clear that we as a community are fed up with the status quo, we live in a time where climate change is at the forefront of the communities mind. 

EmAGN is interested in participating in the conversation about climate change and how we as architects can help to design the energy efficient and climatically appropriate cities of the future. EmAGN invited a series of prominent voices to discuss the topic, read on for their responses. 

 

Elizabeth Watson Brown

Design Strategy Leader | Architectus

Elizabeth has always believed that with the opportunity to build the infrastructure of our shared lives we have a serious obligation to create responsible and responsive architecture.  

“What we build has huge impact and that impact must be positive.  In the subtropical and tropical realms when we truly understand the climate and natural environment, we have remarkable opportunities to create excellent, sustainable and humane places through low energy passive climatic biophilic design.”

 

Jessica Holz

Sustainability Leader | Aurecon

Jessica leads Aurecon’s sustainability team in Queensland. She believes sustainability should unlock the total value of ownership and reduce the risk of our client’s investments as well as providing ecological and social benefits.  Sustainability is all about thoughtful and appropriate design.

Jessica has over 10 years’ experience in the industry, with expertise in aviation, healthcare, residential, infrastructure, commercial and education sectors for both sustainability and mechanical services.  She is especially interested in preserving and enhancing biodiversity in urban landscapes and how ecosystems underpin social and economic aspects of the built environment.

 

Dr Rosemary Kennedy FRAIA

Director  | Subtropical Cities

Adjunct Associate Professor | QUT

Throughout Rosemary’s career as an architect, academic and teacher, the question that has consistently underpinned her interests and actions is “how can architecture and urban design contribute to environmental and social sustainability most effectively?”. 

“Place-based design that responds to climate and landscape and local lifestyle preferences is the lens through which I view and constantly attempt to answer this question.”

 

 

Russell Hall

Architect | Russell Hall Architects

Russell Hall spent his formative years on a dairy farm in the Fassifern Valley. He studied architecture at the UQ and the QIT (QUT). Russell’s experience in tropical design was cemented by a number of years with the Papua New Guinea Housing Commission, returning to Australia to establish his practice in 1980. 

Anyone who has listened to Russell describe his work will be aware of his passionate belief in the value of the Queensland tradition. Although derived from this tradition, his work designing houses, townhouses, commercial, retail and mixed-use premises establishes an individual and inventive response to place and climate.

Paul Matthew

Architect | Irregular Projects

PHD Candidate | UQ

Paul has been working in architecture in SEQ since 2003.  Paul has worked on a range of residential project varying in scale from extensions to high rise apartments. Currently Paul is completing his PHD on the current condition and future prospects of older high rise apartment buildings. 

“I’m deeply worried about the sustainability of the built environment… Constructing and inhabiting the built environment is one of the most energy intensive and waste generating parts of Australian society.  It’s equally clear that current development practice is highly unsustainable.”

Question 1: What do you believe the pros / cons / alternatives are to Glass Skyscrapers?

 

Many developers of tall buildings focus on views as their selling point and architects oblige with walls of glass that are described as ‘airy’. Towers with glazed facades and no cross ventilation are neither cool nor airy. 

Along with views and daylight, comes glare and heat gain or loss. Even if glazing is low-e, or high performance, the shading coefficient is not enough to replace actual shade that physical barriers provide. 

Ironically, once residents move into glazed apartment towers they find they need blinds for thermal comfort and privacy, and the view is less important day-to-day.

Rosemary Kennedy

A big con is that multi residential projects complying with planning authorities’ regulations enable complete climate denial. 

In Brisbane on a typical 800 m sq. block, the multi-rise apartments will often pack around a central lift with a unit in each corner. 

Assuming a north facing frontage, one will be N.E., another N.W; and at the rear, one S.W. and the other S.E. The S.W unit couldn’t be worse for the climate: stinking hot in the summer afternoons, freezing in winter, no access to the cooling N.E sea breezes, and face-on to the direction of prevailing Brisbane storms. 

The devil couldn’t make it worse.

Russell Hall

Pros: glass skyscrapers can be dense habitation that allows many people to live or work very close to public transport, friends and relatives, cultural facilities and large parks can support a vibrant street life.  Glass can be a durable, low maintenance and high-performance facade material if well designed and specified.

Cons: glass skyscrapers are often designed more as a financial instrument than a part of the built environment.  This leads to low quality construction, poor design and dependence on air-conditioning.  Ill-considered planning and approvals by local authorities often means that glass skyscrapers are not well located and regularly result in greater use of private cars rather than more walking, cycling or public transport use and don’t support street or social lives.

Paul Matthew

Question 2: Will banning glass skyscrapers solve all of our problems in the built environment?

Unfortunately there is no single solution to climate change. 

Each option and pathway has its own set of negative environmental impacts which need to be carefully considered and mitigated.  

Certainly banning the glass sky scraper could make a positive contribution if combined with careful selection of façade materials and building design.  

When considering alternatives to glazing, I would encourage designers to take a life-cycle approach to selecting their materials and look at materials that have a reduced embodied energy, can be disassembled and reused, or have a very long life span depending on what is appropriate for the particular project.  

Other issues that should be considered are the climate zone, reducing air conditioning or heating load through colour selection, designing to reduce the heat island effect and using the building or site to create habitat for local biodiversity

Jessica Holz

No, the high-rise building industry has already begun a shift away from a generation of all-glass facades and is placing more value on place-specific solutions with more overt external shading, and more actual ‘wall’ than glass. 

But buildings can only do so much, and should not have to do everything.  

We need to take a good hard look at what’s happening outside buildings that is stopping us from opening the windows. 

For example, when we rethink how we move in our cities, we can reduce noise and air pollution, and give people more choice to naturally-ventilate the buildings they occupy.

Rosemary Kennedy

Question 3: What, if anything, can we learn from the domestic vernacular of ‘the Queenslander’ when translating it to the civic scale?

Some of the really useful and positive attributes of Queenslanders that it would be excellent to translate into larger buildings at a civic scale are:   

  • The ability to easily split whole buildings into smaller parts, for transportation and reuse elsewhere when their original sites need redevelopment.
  • The use of simple mechanical fixings so that they can be easily disassembled.  This allow their components to be cheaply reused in new buildings.
  • Open and accessible structures which allow services to easily be added or altered, which can prolong a building’s useful life.  
  • Most of the structure and cladding are renewable resources (although these resources have not been sustainably managed).  Further, the parts that are not renewable are highly recyclable (roof sheeting, steel nails, bolts and ant caps, glass).

Paul Matthew

‘The Queenslander’ works when in the right context.  The basic principles are very sound – ideally taking advantage of the prime northern aspect and shading the core of the house with encircling verandahs which then become preferred spaces of occupation in that delightful condition- the interstice between ‘inside’ and ‘outside’ and a powerful symbiotic relationship with gardens and generous spaces between houses to allow the breezes to flow.

The Queenslander relies upon flexibility and open-ability – to tune the house to capture those cooling breezes.  Where they do not work is when jam – packed onto too-small lots, thus requiring energy for thermal comfort and causing major issues with privacy and limiting of natural vegetation.  The lessons of translation of these principles to the civic scale are clear.  Large buildings also need to be designed with appropriate aspect, shading, natural ventilation, and inclusion of natural large scale vegetation. 

Elizabeth Watson Brown
 

Question 4: Do you think the NCC deemed to satisfy energy efficiency requirements are a good enough response to climate change or energy efficiency?

Energy efficiency regulations for building envelopes make most sense in harsh climates (such as Northern Europe) where energy use for heating can be more than 80% of ongoing energy use.  In mild sub-tropical climates, energy use for heating and cooling is typically less than 10% of total ongoing energy use.  

Domestic hot water uses more electricity than heating or air conditioning in many Queensland houses, yet regulations requiring the use of energy efficient hot water systems were removed from the Queensland Development Code in 2012.  

The NCC also completely ignores the energy use and greenhouse gas emissions embodied in building materials and the construction process.  For many buildings this embodied energy results in far greater CO2 emissions and other environmental impacts that than electricity use for domestic hot water and space heating and cooling combined.

Paul Matthew

Those regulations tend to assume and therefore help create sealed, insulated buildings and the assumption of energy input  which then needs to be reduced, and the energy supply itself becomes what need to be controlled for climatic impact minimisation.

What I advocate is minimising energy input through passive design.  

Elizabeth Watson Brown

Stronger policies, and improvements in minimum standards and mandatory requirements and incentives to eliminate carbon emissions are needed urgently to meet Paris Climate Agreement benchmarks.

Rosemary Kennedy

The energy efficiency provisions of the NCC 2019 provide a significant improvement in the legislative mechanism to improve building performance.  There will be a steep learning curve for industry but we are excited to embrace these changes and work with architects to get great façade outcomes.

In terms of climate change policy more broadly, I think we could do a lot more as a nation.  Similarly for addressing other environmental issues and biodiversity loss.

Jessica Holz

High-rise offices are mostly totally sealed glass boxes. Worse yet… (they) now mimic office buildings. Hard to tell the two apart except for the grotesque glass hand rails on verandas.  

An identifier as to which is which, is apartments have windows opening a maximum of 125 mm so the sacred sphere of the BCA does not fit through. Successful natural ventilation in a sub-tropical climate is impossible.   

To reinforce this, NCC, Vol 2, ‘Part 3.8.5 Ventilation’ asks for 5% of the floor area of habitable and other rooms to be the minimum wall ventilation to each room. However, it then qualifies this by a clause which says:

‘Explanatory Information:

The ventilating area of a window is measured as the size of the openable sash of the window. This is the case regardless of the type of window, i.e. whether it is an awning casement or sliding window and irrespective of the restrictions on the openable sash.’ 

No clause more clearly portrays how design in Sub-Tropical/Tropical regions is controlled by people not living there. It’s bizarre for any climate. What is the point of a 5% ventilation area if it can be zero? 

The scribes of this need to be made aware: an open window can be closed. In any event, even under the current law, the min requirement of a true 5% of the floor area to be ‘clear ventilation’ is possible to meet the Code’s need of 125 mm maximum openings. If the Code did not have the qualifier referred to above, safe openings of at least 5% of the floor area can be provided. 

The writes of the NCC ignore both the needs of the occupants and the climatic performance when providing their blunt and inflexible means of dealing with safety. This enables developers to build inappropriate buildings. To have a fully clear 5% would cost more than what is commonly done now. It deprives occupants of relying on natural ventilation and entrenches the need for high energy consumption A/C systems.

Which then raises the question,’ how can it be 5% from Hobart to Darwin?’ Surely it must be much greater in hot humid climates. The NCC allows State variations. The problem is the States are reluctant to do so to make the Code fit their unique circumstances. 

Russell Hall

Question 5: What can we as professionals in the built environment do to combat climate change?

I’m just off to march in the student strike for climate so that’s one thing- advocacy!  But the main contribution we can make is responsible action through our designs; truly understanding the science of climate and energy use and designing small footprint buildings and environments understood as part of a biophilic continiuum, which promotes permeability of people, breezes, light, air and  vegetation, and the consequent democracy of accessibility and occupation.

Elizabeth Watson Brown

One way forward is to support and promote ASBEC’s call for a mandatory zero-carbon-ready building code, using the ready-made NCC as the vehicle. The NCC’s performance standards do not preclude the use of fundamental principles of passive climatic design for energy efficient Class 2 buildings. Only the Code’s performance standards are mandatory, yet many developers and architects take the non-mandatory ‘acceptable solutions’ as their starting and end point.

See Built to Perform: An Industry-led Pathway to a Zero Carbon Ready Building Code 

Rosemary Kennedy

Read and learn more about which materials and process are most environmentally damaging and consciously steer clients and other architects and consultants away from those choices.  

Understand the expected lifespan for any new or renovated building and choose the appropriate materials and technologies for that building – there is no sense in designing a concrete frame building that could physically last 200 years if it will be entirely out of date economically and demolished in 50 years.

If you run a practice then sign up to Architects Declare Climate Emergency…

Paul Matthew

Question 6: What do you believe the future of glass skyscrapers will be?

Note there are places in the world where people cannot afford the energy to ‘run’ sealed glass skyscrapers, (and the earth certainly cannot afford that type of high-carbon architecture) and they are occupying them by punching out the glass to allow natural air flow.  We as architects need to take serious lessons from that.

Elizabeth Watson Brown 

I don’t think the tall glass building has a future.

Rosemary Kennedy

They’ll make great refurbishment projects in 20-30 years.

Paul Matthew

In the sub-tropical/ tropical climates shading the façades avoids solar heat gain. If made of photovoltaics, the shades become an inherent electricity source for the building. The optimum fixed angles will vary with latitude and orientation to give different expressions to correct environmental solutions. In Brisbane, at 27 degree south, the sun never shines from true south; the low angle summer morning and afternoon sun can be controlled by vertical shades on the south. 

Adjustable shades enable greater shade control and, the more successful the shade, the more power generated with solar panels as the top surface. A solar shade moving to always be perpendicular to the sun gains more power. However, the cost to do so is infinitely more expensive than moving on a single axis.

Russell Hall