What Are ZEH and Energy Efficiency Standard Strengthening?
"ZEH (Net Zero Energy House)" refers to homes that significantly reduce energy consumption through improved insulation performance and high-efficiency equipment installation, with renewable energy systems like solar panels compensating for remaining energy needs, achieving approximately zero net primary energy consumption on an annual basis.
Following the 2022 amendment to the Building Energy Efficiency Law, compliance with energy efficiency standards for new residential buildings and non-residential structures is being phased in as mandatory. From April 2025, energy efficiency standard compliance will become a principle obligation for all buildings including new homes, and the government has indicated that ZEH-level performance will become the standard benchmark from 2030 onwards.
This is not merely a change in building regulations. It represents a fundamental shift affecting rental property asset values, tenant selection behavior, and operating cost structures in real estate investment.
Risks of Existing Properties with Poor Energy Efficiency
Existing rental properties with low insulation performance face the greatest risk in this shift.
Asset value depreciation is the primary concern. Properties not meeting energy efficiency standards may become evaluated negatively by financial institutions in the future. Some financial institutions are already offering preferential lending terms for high-efficiency properties. Medium to long-term, market liquidity of low-performance properties will decline, and the risk of facing unfavorable conditions at sale increases significantly.
Impact on occupancy rates cannot be overlooked. Tenants sensitive to living costs increasingly prefer high-insulation, airtight properties with lower utility costs. Particularly as electricity rates rise, prospective tenants recognize that monthly utility cost differences impact their living expenses more than rent amounts. Older, poorly insulated properties will increasingly face pressure to reduce rents in competitive comparisons.
Cost increases for repairs and updates also require consideration. Properties may face demands for energy efficiency-compliant renovations in the future, and compliance costs can be substantial depending on property size. Investors must decide whether to invest proactively now or seek exit strategies while maintaining current conditions.
Investment Advantages of High Energy Efficiency Properties
Conversely, investors acquiring properties meeting ZEH and energy efficiency standards, or acquiring new high-performance properties, enjoy several clear advantages.
Subsidy systems such as "Green Housing Points" and "Childcare Eco-Home Support Programs" provide subsidies and tax incentives for high-efficiency new construction and renovation projects. By utilizing these systems, investors can sometimes recover portions of initial investment costs. Since program content changes annually, confirming the latest information at purchase or renovation timing is critical.
Rental premium potential is also notable. High-insulation properties with controlled energy costs present lower effective residential costs when including utility expenses, creating motivation for tenants to accept slightly higher rents. This is particularly appealing to families considering long-term residence and remote workers concerned about utility costs.
Evaluation increases from ESG investment perspectives represent another notable trend. Institutional investors and real estate funds increasingly incorporate environmental performance into investment criteria, making it important to now recognize whether properties will be favorably evaluated at future sales.
Realistic Response Measures for Existing Property Owners
Comprehensively retrofitting all existing properties to ZEH standards simultaneously is not realistic. What responses can investors with existing properties pursue?
Phased insulation renovation represents the most realistic approach. By combining relatively small-scale work—such as double-glazing windows, installing interior windows, adding insulation materials, and switching to LED lighting—at vacancy timing or during major repairs, energy efficiency performance can be improved gradually.
Switching to high-efficiency water heaters and air conditioning systems offers immediate impact. Upgrading to eco-cute systems, heat pump water heaters, or inverter-type air conditioning can naturally occur when equipment reaches end-of-life. These offer good cost-performance and directly contribute to tenant utility cost reduction.
Installing solar power systems is particularly effective for apartment complexes and rental homes. By supplying electricity to common areas, management costs can be reduced and properties gain differentiation advantages. However, effectiveness varies significantly based on roof structure, orientation, and sunlight conditions, making pre-installation expert consultation essential.
Confirmation Points for Energy Efficiency Performance in Investment Property Selection
When acquiring new properties, incorporating energy efficiency performance into investment decision-making is important.
Presence of building confirmation certificates and performance evaluation reports serves as a key indicator of property energy efficiency. Properties obtaining BELS (Building Energy Efficiency Performance Labeling System) ratings have third-party confirmed energy performance, providing comparison standards.
Confirmation of construction year and insulation specifications is also important. Properties built after 1999 likely comply with next-generation energy efficiency standards, and those from 2016 onwards may incorporate upgraded energy efficiency specifications. Develop the habit of confirming insulation material types and thickness with sellers or property management companies.
Additionally, obtaining actual utility cost data where available helps confirm tenants' actual utility cost levels. Abnormally high utility costs may reflect poor insulation performance.
Long-Term Investment Strategy Direction
Decarbonization trends represent structural changes driven from three directions—policy, market, and finance—transforming the real estate market, not short-term fads.
Investors can pursue two broad strategies in response to this change. One approach involves acquiring and holding high-performance properties to build "energy-efficiency compliant" portfolios. The other involves systematically replacing lower-performance properties while timing transitions to maintain and improve overall portfolio quality.
In either case, viewing energy efficiency not as "nice-to-have added value" but as "the foundation for sustained rental income" has become essential for medium to long-term real estate investment strategy.