When an investor sizes up an office building in Panama City or Montevideo, the conversation usually starts with location, price per square metre and occupancy rate. Energy shows up late, almost as a footnote. That is a sequencing error. In a commercial building located in the tropics, the largest recurring operating line item is neither cleaning nor security: it is the electricity the air-conditioning system burns to keep floors of offices habitable under a near-vertical sun and high humidity almost year-round. That single factor — the cooling load — shapes the monthly bill, the return on any retrofit and, increasingly, the legal framework the building must meet. And this is precisely where Panama (PA) and Uruguay (UY), the two markets this publication follows, diverge in a way worth understanding before you sign.
Cooling load: the factor that defines consumption in the tropics
The physics is simple and unforgiving. A building in a temperate climate spends energy on heating in winter and on cooling in summer; the two peaks split the year. A building in a humid tropical climate like Panama’s (PA) almost never heats — it cools from January to December. Air conditioning stops being a seasonal machine and becomes the building’s permanent energy heart.
The figures available for Panama show the scale of it. According to an analysis on decarbonising cooling in Panama published on the illuminem platform (2023), cooling and refrigeration account for roughly 53% of the country’s final energy demand — a direct reflection of the climate. The same analysis notes that the commercial sector is Panama’s single largest electricity consumer, at more than 40% of national electricity use, and projects that by 2050 close to 48.6% of that commercial sector’s electricity consumption will come from air conditioning alone (illuminem, 2023, on national data; SECONDARY, to be confirmed against a primary sector source). Even taking these numbers with the caution a secondary source warrants, the direction is unmistakable: in the tropics, whoever controls the cooling load controls the building’s power bill.
This has a practical consequence for the commercial owner. The efficiency of a tropical building is not won, first of all, on LED lighting or on lifts, useful as both are. It is won on how much heat enters the building — through facade, roof and windows — and on how efficiently the cooling system rejects that heat. Everything else is secondary to those two fronts. Which is why the regulation now emerging in the region points, with growing precision, at exactly that.
Panama: a building code with energy requirements (RES v2)
Panama (PA) made a decision that sets it apart in the region: it gave itself a mandatory sustainable building code that includes energy-performance requirements for the building itself. The Sustainable Building Regulation (Reglamento de Edificación Sostenible, RES) was first approved on 26 June 2019 (Gaceta Oficial; primary source). The current version — known as RES v2, drafted as a 2022 revision — was adopted by resolution of the Board of Engineering and Architecture (JTIA Resolution No. 002 of 13 January 2023) and entered into force on 1 August 2023, per its publication in Gaceta Oficial No. 29726 of 23 February 2023 (primary source).
What matters here is the content, not the date. RES v2 places energy efficiency among its core sections and targets the cooling load head-on: it introduces requirements on the building’s thermal envelope — that is, on how much heat the building’s skin lets in — and on the design of air-conditioning equipment, with a simplified verification method so that architects and engineers can comply without full energy modelling (Gaceta Oficial No. 29726, 2023; and sector technical guidance, SECONDARY). The regulation is organised into several sections — general conditions, energy efficiency, sustainable site, water-use efficiency, materials and resources, among others — and states that it aligns with international sustainable-construction standards such as LEED and BREEAM.
RES did not appear from nowhere. Panama had been preparing the ground since its Sustainable Construction Guide (Guía de Construcción Sostenible), approved by resolution in 2016 after an initiative begun in 2013, in which the then National Energy Secretariat drew on the International Finance Corporation (IFC, World Bank Group) to develop building energy-saving guidance (Gaceta Oficial / IFC, 2016; primary source). Above the sector code sits a broader energy-efficiency framework: Law 69 of 12 October 2012 on the rational and efficient use of energy (the UREE Law), published in Gaceta Oficial 27145-A and regulated by Executive Decree 398 of 2013 (National Assembly of Panama; primary source). That law sets the general guidelines of national energy-efficiency policy and covers incentives, standardisation, labelling and certification, with implementation led by the Executive Branch through the National Energy Secretariat.
For a commercial owner in Panama, the reading is direct: there is a regulatory requirement that touches the energy performance of the building, not only of its appliances. Compliance is no longer voluntary — it becomes part of the building permit and of the design from the first drawing.
Uruguay: efficiency labelling for appliances, not buildings (Law 18.597)
Uruguay (UY) arrived at energy efficiency early, but through a different door. Its framework instrument is Law No. 18.597 on the efficient use of energy, approved on 21 September 2009 (IMPO / MIEM; primary source). This law created the country’s energy-efficiency institutions and, in its Article 15, assigned to the Energy and Water Services Regulatory Unit (URSEA) the task of monitoring compliance with energy-efficiency labelling (URSEA / Law 18.597; primary source).
The decisive difference lies in the scope of that labelling. The National Energy Efficiency Labelling System, developed out of Law 18.597 and Decree 211/015, requires energy-using equipment to be sold with a label stating its consumption and performance; the programme began in 2009 with lamps and water heaters and added domestic refrigerators from 2010 (MIEM / URSEA; primary source). Its mandatory scope covers appliances, equipment and vehicles — not buildings. There is a voluntary scheme, promoted by MIEM and URSEA, for labelling efficient homes, but it is neither mandatory nor widely applied (MIEM / URSEA; primary source, current status).
Here it pays to be precise, so as not to mislead. As of this publication, Uruguay does not have a mandatory building energy code equivalent to Panama’s RES v2. It regulates the efficiency of the refrigerator, the air conditioner and the lamp sold in the country; it does not, on a mandatory basis, regulate how much heat an office building’s facade lets in. This is not a criticism. Uruguay’s temperate climate means the cooling load weighs far less than in Panama, and the country concentrated its climate policy on the generation matrix — where it reached renewable shares near 99% in 2024, per MIEM figures reported by specialist press (SECONDARY) — rather than on the building envelope. But for an investor comparing the two markets, the operational conclusion matters: in Panama, building efficiency is a legal obligation; in Uruguay, it is a voluntary, market-driven choice.
What actually moves the needle in a tropical building
Whether or not the law requires it, the measures that cut cooling load in the tropics are well known and can be ranked. The logic is straightforward: first, keep the heat out; then, cool efficiently the heat that inevitably gets in.
Envelope and window shading. The first front is the building’s skin. In a tropical climate, solar heat gain through unshaded glass is enormous, and shading windows directly reduces that thermal input (regional technical studies from UNEP-C2E2 and the Technological University of Panama; SECONDARY). Overhangs, brise-soleil, low-emissivity glazing and smart facade orientation act before the air conditioning has to work at all. This is why RES v2 starts precisely with the thermal envelope: every kilowatt of heat kept out is a kilowatt the chiller does not have to reject.
Efficiency of the cooling system. The second front is how the building cools. A modern air-conditioning unit with a high seasonal efficiency rating delivers the same comfort at a fraction of an old unit’s consumption. In a building where air conditioning can represent half of electricity use, an efficiency step-change in the equipment translates straight to the bill. RES v2 sets requirements on the design of this equipment precisely because it is the lever with the highest per-unit impact.
Lighting, controls and behaviour. The third, complementary front combines LED lighting, occupancy sensors and time-of-day controls. It does not rival cooling in magnitude, but it is low cost and quick to pay back, and it indirectly reduces internal heat load: less heat emitted by fixtures means less work for the air conditioning.
The order of this list is not incidental. In the tropics, spending first on solar panels or on lighting before tackling the envelope and the cooling system optimises the margin ahead of the core. The cheapest energy is still the energy not consumed, and in a tropical building that energy sits, above all, in the heat that is avoided.
The investment dimension: from CAPEX to certification
For the investor, the energy efficiency of a tropical building is not an environmental gesture: it is a financial variable. Every point of reduction in air-conditioning consumption flows, month after month, into the building’s operating result, and in markets where energy is paid in US dollars — such as Panama, a dollarised economy where the US dollar is legal tender — that saving is calculated without currency risk, which simplifies the return on investment (market context).
There is, in addition, a certification layer that turns efficiency into a verifiable asset. The EDGE standard (Excellence in Design for Greater Efficiencies), developed by the IFC of the World Bank Group for emerging markets, requires a minimum of 20% reduction in energy use, water use and embodied carbon of materials against a local baseline building (EDGE / IFC; primary source). It is a threshold reachable with the measures described and serves as a bridge to more demanding schemes such as LEED. Globally, EDGE reports more than 65 million square metres certified, saving more than 1.3 million tonnes of CO₂ per year (EDGE, 2023-2024; primary source, global figure). Both Uruguay and Panama have EDGE-certified projects and accredited auditors in the region (GBCI / EDGE; primary source).
It is the combination that makes the investment case. In Panama, the legal framework (RES v2, the UREE Law) pushes energy performance from the side of obligation, and EDGE certification turns it into a sellable mark for corporate tenants and lenders. In Uruguay, where the building obligation does not exist, efficiency and certification are a positioning choice: an efficient building differentiates the owner in a market that does not yet demand it — and it does so in a country whose electricity matrix is already almost entirely renewable, so that efficiency reinforces, rather than replaces, an environmental credential the grid delivers by default.
Conclusions
Three ideas sum up the picture for anyone who builds, operates or invests in offices in the Latin American tropics.
First, cooling load is the axis. In Panama, where cooling represents around 53% of final energy demand (illuminem, 2023; SECONDARY), the efficiency of a commercial building is decided in its thermal envelope and its cooling system, not in the details. Any analysis that starts elsewhere starts wrong.
Second, the regulatory distinction between the two markets is real and consequential. Panama (PA) has a building code with mandatory energy requirements — RES v2, in force since 1 August 2023 (Gaceta Oficial No. 29726, 2023) — backed by the 2012 UREE Law. Uruguay (UY) mandates the efficiency of equipment, through the labelling born of the 2009 Law 18.597 (URSEA / MIEM), but not the efficiency of buildings. Confusing the two regimes leads to mistaken expectations when crossing the border.
Third, efficiency pays in both markets, for different reasons. In Panama, because energy costs money — in dollars — and the law already watches it. In Uruguay, because it differentiates a building in a market that does not yet require it. In both, a certification such as EDGE, with its 20% threshold (IFC), turns operational savings into a verifiable asset. Energy efficiency in the tropics is not a sustainability checkbox: it is, quite simply, the largest operating item an office building can manage.
This article is for general information only and does not constitute legal, tax or financial advice.