why glass buildings are costly in the tropics
panamá’s skyline has transformed rapidly over the last two decades. glass façades now dominate our urban landscape, shimmering towers that promise modernity, transparency, and prestige. yet beneath their polished surfaces lies a contradiction: these aesthetic decisions come at a steep environmental and economic cost.
as an architect working in the tropics, i see every day how the overuse of unprotected glass façades defies both climate logic and sustainable design principles. in a country with high electricity costs, and high heat year-round, a glass building becomes not a symbol of progress, but a monument to inefficiency.
local observations
many office towers feature continuous glass façades in all directions. during the afternoon, you can see mirrored reflections of the sun bouncing onto neighboring façades, multiplying heat and glare.
meanwhile, older tropical buildings (those with deep balconies, shaded verandas, or ventilated roofs) often maintain reasonable indoor conditions with minimal cooling. their appearance may be less “corporate,” but their logic is profoundly sustainable.
i avoid naming specific projects out of respect for peers. the point is not to criticize individuals but to question a trend: why do we keep repeating a typology that works against our own climate?
the energy context of panamá
electricity in panamá is expensive. as of 2024, residential rates average around USD 0.175 per kwh, while commercial users pay closer to USD 0.196 per kwh¹. the national electricity market operates between 169 and 199 USD/mwh, or roughly the same 0.17–0.20 USD/kwh².
this positions panamá among high electricity cost nations, with higher prices than costa rica or el salvador. the reasons are structural: generation heavily depends on hydroelectricity, but variability in rainfall and the need for fossil-fuel backup add volatility. for any air-conditioned building, these rates translate into significant operational costs, and for a fully glazed building in the tropics, those costs multiply.
the greenhouse effect of glass buildings
glass is seductive. it floods interiors with daylight and offers sweeping views. but in tropical climates, its behavior under direct solar radiation is problematic.
sunlight enters as short-wave radiation, strikes interior surfaces, and is re-emitted as long-wave infrared heat. most glass is opaque to these longer wavelengths, trapping heat inside: the greenhouse effect. the result is higher indoor temperatures and an increased dependence on mechanical cooling.
research in tropical climates has quantified this effect. studies show that high-glazing-ratio façades can increase cooling energy demand by 25–50 % compared to balanced envelope designs³. even when using solar-control or low-emissivity glass, the thermal load remains substantial. a 2017 evaluation of glass performance metrics concluded that standard clear glass performs poorly in tropical latitudes, while tinted or coated glass only partially mitigates the problem⁴.
the hidden cost of aesthetics
when architects specify glass façades in tropical cities, the decision is often aesthetic or symbolic, “modern,” “corporate,” or “transparent.” rarely is it based on climate or performance.
however, every square meter of exposed glass increases internal heat gain, raising both cooling load and installed hvac capacity. this mechanical dependence creates a feedback loop: the more glass, the more cooling; the more cooling, the higher the bills; the higher the bills, the more pressure to cut comfort or efficiency elsewhere. let’s not forget that the heat trapped inside glass buildings doesn’t disappear, it just gets pushed outside and into the city, exacerbating the urban heat island effect.
for building owners, this translates into thousands of dollars in annual energy expenses. if a typical office tower consumes 100,000 kwh/year for air conditioning, a 25–50 % excess from poor façade design adds 25,000–50,000 kwh/year, or roughly USD 4,000–8,500 annually, depending on tariff levels. over a 25-year lifespan, the difference can exceed USD 200,000, excluding maintenance and equipment replacement.
this is a non-marginal issue that defines the building’s long-term sustainability and economic performance.
the irony of mechanically-dependent modernism
there’s a philosophical irony at play. the international style,which popularized glass façades, emerged from temperate contexts where solar gain was welcome. copied uncritically to the tropics, it becomes self-defeating.
in panamá’s hot-humid climate, full-glass buildings require mechanical cooling 24 hours a day. if the chiller fails or the power grid cuts off, comfort collapses instantly. compare this to vernacular or climate-responsive buildings that remain habitable even when systems are off.
when architecture relies entirely on energy to correct its own environmental mistakes, it ceases to be sustainable or even reasonable, no matter how many green labels it carries.
smarter tropical design strategies
panamá has centuries of climatic wisdom embedded in its traditional architecture. the same principles can inform contemporary design without sacrificing modernity.
1. shading devices - horizontal overhangs, vertical fins, and brise-soleil elements block direct sun before it hits the glass. even a 1 m overhang can cut solar exposure on upper floors by 50%.
2. external louvers and screens - adjustable shading (metal, perforated mesh, or wood) allows occupants to control glare and heat gain dynamically.
3. selective glazing - low-e or spectrally selective glass reduces solar heat gain while maintaining visible light. reflective or tinted coatings should be tuned to orientation.
4. natural ventilation - cross-ventilation, stack effect openings, and nighttime flushing dissipate accumulated heat.
5. double-skin façades - creating an air cavity between outer and inner glass layers allows ventilation to expel hot air⁵.
6. thermal mass - concrete or masonry walls act as buffers, absorbing daytime heat and releasing it at night.
7. retrofit measures - for existing glass buildings, window films, shading additions, or partial recladding can cut cooling loads by up to 27 %⁶.
quantifying the impact
let’s contextualize the numbers.
- a typical 10-story commercial building with full glass façades can have 40–60 % higher solar heat gain compared to an optimized design.
- cooling energy in such buildings often represents 60–70 % of total electricity consumption⁷.
- if tariffs rise (as they did in early 2024 by 2–15 % depending on customer class⁸), operational costs can escalate even faster than inflation.
- nationwide, commercial buildings account for roughly 35 % of total electricity use, a figure expected to grow with urban densification⁹.
reducing façade gains is therefore one of the most direct and cost-effective pathways to cut urban energy demand.
our design philosophy
at entrópica, we begin every project by understanding its climatic forces: orientation, prevailing winds, humidity, and solar geometry. unprotected glass is never a default.
1. climate first - we model the sun’s path and evaluate the façade’s behavior using simulation tools like energyplus and ladybug to predict energy consumption.
2. balance and modulation - we combine transparent and opaque materials strategically, adding shade where necessary.
3. aesthetics through performance - beauty emerges when form and energy logic align, when a façade both delights and protects.
lower heat gains → smaller mechanical equipment → lower upfront AND lifetime costs
this approach merges art, science, and responsibility. it’s how sustainable architecture must evolve in the tropics: not through imported styles, but through local intelligence.
conclusion
sustainable architecture in panamá is not a matter of certifications or slogans, it is a matter of coherence. a glass tower cooled by massive chillers is not sustainable simply because it installs efficient equipment. sustainability begins when design decisions themselves. form, material, and orientation reduce the need for that equipment.
glass can be part of tropical architecture, but only when used consciously, shaded intelligently, and sized according to purpose. every square meter of façade is a long-term energy decision.
in a country where electricity is expensive and the climate is unforgiving, embracing context is the most progressive thing an architect can do.
if you are developing or designing in the region, entrópica can help you simulate, measure, and optimize your project’s energy performance, ensuring that beauty, comfort, and efficiency coexist under the same roof.
bibliography
- globalpetrolprices (2024). electricity prices in panama. https://www.globalpetrolprices.com/panama/electricity_prices
- climatescope (2024). panama energy market overview. https://www.global-climatescope.org/markets/panama
- sciencedirect (2023). advances in retrofitting strategies for energy efficiency in tropical climates. https://www.sciencedirect.com/science/article/abs/pii/s0378778823005741
- sciencedirect (2017). evaluation of building glass performance metrics for the tropical climate. https://www.sciencedirect.com/science/article/abs/pii/s0378778817300336
- wikipedia (2024). double-skin façade. https://en.wikipedia.org/wiki/double-skin_facade
- mdpi (2024). buildings journal, vol. 14 (6): 1633. https://www.mdpi.com/2075-5309/14/6/1633
- springer (2024). improving energy performance in tropical office buildings. https://link.springer.com/chapter/10.1007/978-981-97-8401-1_16
- prensa latina (2024). electricity tariff prices increase in panama. https://www.plenglish.com/news/2024/01/17/electricity-tariff-prices-increase-in-panama
- enerdata (2024). panama country energy profile. https://www.enerdata.net/estore/country-profiles/panama.html
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