Data story: Global net-zero building performance — what the operational data actually shows

Why It Matters

Buildings consume approximately 30 percent of global final energy and generate 26 percent of energy-related CO₂ emissions, with roughly 8 percent from direct on-site combustion and 18 percent from electricity and heat production (IEA, 2025). Net-zero energy buildings (NZEBs) are designed to produce as much energy as they consume on an annual basis, making them central to every credible decarbonisation pathway for the built environment. Yet a persistent gap between designed and actual performance has dogged the sector for decades. The New Buildings Institute (NBI) found in its 2025 Getting to Zero database update that verified net-zero buildings achieve a median energy use intensity (EUI) of 29 kBtu per square foot per year, roughly 65 percent below the US commercial building stock average of 83 kBtu/ft²/yr (NBI, 2025). However, nearly one in five buildings that targeted net-zero certification failed to meet their designed EUI within the first two years of operation. Understanding what separates high performers from underperformers is critical for sustainability teams, policymakers and investors allocating capital to building decarbonisation. This data story examines the operational evidence from over 900 verified and emerging net-zero projects worldwide, identifies the variables that most reliably predict performance, and benchmarks deep retrofits against new construction.

Key Concepts

Energy Use Intensity (EUI) measures a building's annual energy consumption per unit of floor area, typically expressed in kBtu per square foot per year (kBtu/ft²/yr) or kilowatt-hours per square metre per year (kWh/m²/yr). Lower EUI indicates higher efficiency. A conventional US office building averages 80 to 100 kBtu/ft²/yr, while a net-zero office typically operates at 20 to 35 kBtu/ft²/yr.

The performance gap is the difference between a building's designed (modelled) energy consumption and its actual metered consumption once occupied. Meta-analyses by the Chartered Institution of Building Services Engineers (CIBSE) and University College London have consistently documented gaps of 30 to 150 percent in commercial buildings, meaning actual energy use is often 1.3 to 2.5 times what was predicted (CIBSE, 2024). Understanding and closing this gap is the central challenge for net-zero building certification.

Net-zero energy vs. net-zero carbon. A net-zero energy building balances annual energy consumption with on-site or procured renewable energy generation. A net-zero carbon building goes further by addressing both operational and embodied carbon across the full lifecycle. Most current certification programmes, including the International Living Future Institute's (ILFI) Zero Energy Certification and NBI's Getting to Zero programme, focus on operational energy, but lifecycle-based standards such as LEED Zero and the World Green Building Council's Net Zero Carbon Buildings Commitment are driving the sector toward whole-life carbon accounting.

Deep energy retrofits reduce a building's energy consumption by 50 percent or more through comprehensive envelope upgrades, HVAC system replacement, lighting modernisation and controls integration. The Global Buildings Performance Network and Rocky Mountain Institute have documented that deep retrofits can achieve EUIs of 30 to 50 kBtu/ft²/yr in buildings originally consuming 100 to 150 kBtu/ft²/yr (RMI, 2025).

The Data

The most comprehensive global dataset on net-zero building performance comes from NBI's Getting to Zero database, which as of January 2026 tracks 922 verified and emerging zero-energy and zero-carbon buildings across 50 countries (NBI, 2025). Additional performance data comes from the European Commission's Nearly Zero-Energy Buildings (nZEB) monitoring programme covering 27 EU member states, the Canada Green Building Council's Zero Carbon Building Standard portfolio of 120 certified projects, and the Building Research Establishment (BRE) in the United Kingdom.

Across verified NZEBs in the NBI database, the median measured EUI is 29 kBtu/ft²/yr (approximately 91 kWh/m²/yr), with the 25th percentile at 19 kBtu/ft²/yr and the 75th percentile at 42 kBtu/ft²/yr. The interquartile range reflects significant variation driven by building type, climate zone and occupancy patterns.

The performance gap across the dataset averages 16 percent, meaning that actual EUI exceeds designed EUI by an average of 16 percent. This represents a marked improvement from the 30 to 40 percent gaps documented in conventional buildings and reflects the benefit of integrated design processes, commissioning and post-occupancy monitoring that are standard practice in net-zero projects. However, the distribution is skewed: the best-performing quartile actually outperforms its design targets by 5 to 10 percent, while the worst-performing quartile exceeds targets by 35 to 60 percent (NBI, 2025).

Building type has the strongest influence on EUI outcomes. Net-zero K-12 schools achieve the lowest median EUI at 22 kBtu/ft²/yr, followed by offices at 28, multifamily residential at 33, and laboratories and healthcare facilities at 55 to 75. Climate zone is the second-strongest predictor, with buildings in ASHRAE Climate Zones 4 and 5 (temperate) achieving the lowest EUIs and those in Zones 1-2 (hot-humid) and 7-8 (very cold) consuming 20 to 40 percent more.

Trend Analysis

The number of verified net-zero buildings has grown at a compound annual growth rate of 38 percent since 2019, accelerating from 255 verified projects globally to over 900 by early 2026 (NBI, 2025). This acceleration is driven by three converging forces: tightening building energy codes, falling renewable energy costs and expanding green finance for high-performance buildings.

Performance is improving over time. Buildings completed after 2022 show a median performance gap of 12 percent, down from 22 percent for those completed between 2018 and 2021. The improvement correlates with the adoption of advanced building automation systems, improved commissioning protocols and the increasing use of digital twins for operational optimisation. Johnson Controls reported in 2025 that buildings using its OpenBlue digital platform achieved average energy savings of 25 percent within 12 months of deployment (Johnson Controls, 2025).

Deep energy retrofits are gaining ground but remain a small share of the total. Of the 922 buildings in the NBI database, 147 (16 percent) are retrofits. These achieve a median EUI of 38 kBtu/ft²/yr, roughly 30 percent higher than new construction, but they reduce pre-retrofit consumption by an average of 62 percent. The Empire State Building retrofit, led by Johnson Controls and Rocky Mountain Institute, reduced energy consumption by 40 percent and served as a proof of concept for commercial deep retrofits (RMI, 2025). More recently, Retrofit Accelerator programmes in New York City and London have scaled deep retrofit deployment, with NYC's programme completing 1,200 building retrofits saving a combined 130,000 tonnes of CO₂ annually by 2025 (NYC Mayor's Office, 2025).

Renewable energy generation is a critical variable. Across the NBI database, on-site solar PV supplies an average of 73 percent of annual energy consumption in verified NZEBs, with the remainder covered by off-site renewable energy procurement through power purchase agreements or renewable energy certificates. Buildings with on-site solar plus battery storage systems achieve the highest rates of self-consumption and are most likely to meet net-zero targets consistently across years.

Regional Patterns

North America leads in absolute numbers, with 512 verified NZEBs representing 56 percent of the global total. The United States accounts for 430 of these, concentrated in California (108), the Pacific Northwest (76) and the Northeast (64). Canada contributes 82 verified projects, with strong representation in British Columbia and Ontario. The US Inflation Reduction Act's tax credits for energy-efficient commercial buildings (Section 179D) and residential properties (Section 45L) have driven a 45 percent increase in net-zero project registrations since 2023 (US DOE, 2025).

Europe accounts for 298 verified projects (32 percent). The EU's nearly zero-energy building (nZEB) standard, which has been mandatory for all new construction since 2021, has created a regulatory floor that drives performance. However, the nZEB standard is less stringent than true net-zero: EU nZEBs typically achieve EUIs of 40 to 60 kWh/m²/yr (13 to 19 kBtu/ft²/yr) for residential buildings but often rely on grid electricity that still has significant carbon intensity in Eastern European member states. Leading markets include the Netherlands, France, Germany and the Nordic countries. The United Kingdom, outside the EU framework, has seen rapid growth through the UK Green Building Council's Net Zero Carbon Buildings Framework and the Passivhaus Trust (UKGBC, 2025).

Asia-Pacific is the fastest-growing region with 112 verified projects (12 percent of global total) but the steepest trajectory. Singapore's Green Mark Platinum programme, Japan's ZEB roadmap targeting net-zero for all new public buildings by 2030, and China's ultra-low-energy building programme are driving growth. Singapore's Building and Construction Authority reports that 53 percent of the city-state's building stock by gross floor area has achieved Green Mark certification, with 42 Green Mark Platinum Zero Energy buildings operational by 2025 (BCA Singapore, 2025).

Sector-Specific KPI Benchmarks

What the Data Suggests

The operational data points to five actionable conclusions. First, net-zero buildings are no longer experimental. With over 900 verified projects across diverse climates, building types and construction methods, the technical feasibility is established. The question has shifted from whether to how fast.

Second, the performance gap is closing but unevenly. Buildings that invest in enhanced commissioning, post-occupancy monitoring and continuous optimisation through digital twins consistently outperform their design targets. Buildings that treat handover as the end of the process routinely underperform. Schneider Electric's EcoStruxure platform has demonstrated 10 to 20 percent additional savings through continuous fault detection and diagnostics in net-zero buildings (Schneider Electric, 2025).

Third, deep retrofits are the sleeping giant. The existing building stock represents roughly 80 percent of the buildings that will be standing in 2050. New construction alone cannot deliver sector-wide decarbonisation. The data shows that deep retrofits can achieve EUIs of 30 to 50 kBtu/ft²/yr, but only 16 percent of verified net-zero projects are retrofits. Scaling retrofit activity requires addressing split incentives between landlords and tenants, financing barriers and disruption concerns.

Fourth, regional policy design matters enormously. Markets with stringent building energy codes, financial incentives and mandatory performance disclosure consistently produce more NZEBs and achieve better outcomes. California's Title 24, the EU nZEB standard and Singapore's Green Mark programme demonstrate the power of regulatory push combined with financial pull.

Fifth, embodied carbon is becoming the next frontier. As operational energy falls, the share of lifecycle emissions from materials rises. Buildings achieving operational net-zero but ignoring embodied carbon may still carry significant climate liabilities. Whole-life carbon assessment, as required by the revised EU EPBD from 2028, will become standard practice.

Key Players

Established Leaders

• New Buildings Institute (NBI) — Maintains the global Getting to Zero database with 922 verified and emerging NZEBs. Primary data source for net-zero building benchmarks.
• International Living Future Institute (ILFI) — Operates the Living Building Challenge and Zero Energy Certification, the most rigorous performance-based net-zero standards.
• Passive House Institute — Sets the Passivhaus standard achieving EUIs below 15 kWh/m²/yr for heating and cooling, serving as the technical foundation for many NZEBs.
• Johnson Controls — OpenBlue digital platform deployed across thousands of buildings, enabling continuous energy optimisation and fault detection.
• Schneider Electric — EcoStruxure Building platform providing integrated building management, energy monitoring and sustainability reporting.

Emerging Startups

• BrainBox AI — Autonomous HVAC optimisation using deep learning, achieving 20 to 25 percent energy reductions in commercial buildings.
• Measurabl — ESG data management platform used by over 15 billion square feet of commercial real estate for performance tracking and disclosure.
• Hive Power — AI-driven energy management for buildings with solar and battery storage, optimising self-consumption and grid interaction.
• QEA Tech — Infrared drone surveys for rapid building envelope diagnostics, enabling targeted retrofit interventions.

Key Investors and Funders

• World Green Building Council — Coordinates the Net Zero Carbon Buildings Commitment with over 170 signatory companies and cities.
• CRREM (Carbon Risk Real Estate Monitor) — Provides science-based decarbonisation pathways for commercial real estate portfolios.
• Green Climate Fund — Financing building efficiency programmes in developing countries, with $2.3 billion allocated to energy-efficient buildings.
• European Investment Bank — Largest multilateral funder of building renovation, supporting the EU Renovation Wave strategy.

Action Checklist

• Benchmark every building against the NBI Getting to Zero database and CRREM pathways to identify performance gaps and stranding risk.
• Close the performance gap by mandating enhanced commissioning, 12-month post-occupancy evaluation and continuous energy monitoring through digital twins or building automation systems.
• Prioritise deep retrofits over shallow interventions. Target a minimum 50 percent energy reduction in existing buildings, using the Energiesprong or Passive House EnerPHit approach for scalable, guaranteed outcomes.
• Integrate embodied and operational carbon by requiring whole-life carbon assessments from concept stage and setting maximum embodied-carbon budgets.
• Leverage policy incentives including the US IRA Section 179D deduction (up to $5.00/ft² for net-zero buildings), EU Renovation Wave grants and Green Climate Fund programmes.
• Disclose building performance publicly through GRESB, ENERGY STAR Portfolio Manager or national disclosure schemes to attract green finance and satisfy tenant ESG requirements.
• Build retrofit pipelines by conducting portfolio-wide energy audits, prioritising buildings with the highest EUI and stranding risk, and bundling projects to achieve economies of scale.

FAQ

How reliable is net-zero building performance data? The most reliable data comes from buildings with 12 or more months of metered energy consumption verified by an independent third party. The NBI Getting to Zero database requires at least one year of operational data for verified status. Self-reported data without third-party verification should be treated with caution, as studies have shown performance claims can be overstated by 15 to 25 percent. The trend toward mandatory performance disclosure in jurisdictions like New York City (Local Law 97), London (NABERS UK) and the EU (EPBD) is improving data quality and availability.

Can existing buildings realistically achieve net-zero? Yes, but it requires a deep energy retrofit combined with on-site or procured renewable energy. The data shows that deep retrofits reduce energy consumption by an average of 62 percent, bringing many buildings within reach of net-zero through the addition of solar PV and efficient electrification. The Energiesprong model, which originated in the Netherlands and has expanded to France, the UK and the US, delivers guaranteed net-zero retrofits for social housing at scale, with energy savings financing the upfront investment over 30-year contracts (Energiesprong, 2025).

What is the cost premium for a net-zero building? Cost premiums for new net-zero construction have fallen to 1 to 5 percent above conventional buildings in most markets, and some developers report cost parity when lifecycle savings in energy and maintenance are factored in. Deep retrofits are more variable, typically costing $50 to $150 per square foot depending on building condition and climate zone. The US DOE's National Renewable Energy Laboratory found that net-zero-ready homes can be built for less than 3 percent above code-minimum cost in most US climate zones (NREL, 2025).

Which building types are hardest to decarbonise? Hospitals, laboratories and data centres have the highest EUIs due to intensive ventilation, process loads and 24/7 operation. Achieving net-zero in these building types requires advanced heat recovery, process-load optimisation and large-scale renewable energy procurement. However, demonstration projects like the Dell Children's Medical Center in Austin (LEED Platinum, 40 percent below baseline EUI) show that deep reductions are achievable even in healthcare facilities.

Sources

• IEA. (2025). Buildings Sector Energy and Emissions Tracking 2025. International Energy Agency.
• NBI. (2025). Getting to Zero Database: 2025 Status Update. New Buildings Institute.
• CIBSE. (2024). Building Performance Evaluation: Bridging the Gap. Chartered Institution of Building Services Engineers.
• RMI. (2025). Deep Retrofit Playbook: Scaling Commercial Building Decarbonisation. Rocky Mountain Institute.
• Johnson Controls. (2025). OpenBlue Buildings: Performance and Sustainability Outcomes Report. Johnson Controls.
• NYC Mayor's Office. (2025). NYC Retrofit Accelerator: 2025 Impact Report. City of New York.
• US DOE. (2025). Zero Energy Buildings: Federal and State Policy Tracker. US Department of Energy.
• UKGBC. (2025). Net Zero Carbon Buildings Framework: Annual Progress Report. UK Green Building Council.
• BCA Singapore. (2025). Green Mark Programme: 2025 Annual Report. Building and Construction Authority Singapore.
• Schneider Electric. (2025). EcoStruxure Building Performance Analytics: Annual Impact Report. Schneider Electric.
• NREL. (2025). Cost Analysis of Net-Zero-Ready Homes by Climate Zone. National Renewable Energy Laboratory.
• Energiesprong. (2025). Market Development Report: Net-Zero Retrofits at Scale. Energiesprong International.
• European Parliament. (2024). Revised Energy Performance of Buildings Directive (EPBD). Official Journal of the European Union.