Environment-Friendly
Developing environmentally friendly buildings
In line with the MIRARTH HOLDINGS Group Policy of "Providing environmentally friendly buildings and spaces," our Group promotes next-generation housing that fully leverages renewable energy. Our aim is to offer eco-friendly homes where families can live with peace of mind. As part of this initiative, we have actively developed condominiums equipped with solar power systems.
ZEH Condominiums
In response to the government's 2030 policy target, which positions collective housing under the Net Zero Energy House (ZEH)* initiative, Takara Leben is actively promoting ZEH-M (ZEH condominiums). Through these efforts, we aim to provide more sustainable, environmentally conscious homes that offer greater comfort and value to our customers.
Since receiving ZEH-M Oriented certification (Nagano Nakagosho Project) in March 2022, we have continued to obtain certifications. In FY2025, we plan to expand certification acquisition across more regions nationwide.
- * Net Zero Energy House (ZEH): A home that simultaneously provides a comfortable indoor environment and achieves an annual net energy consumption of approximately zero or less.
LEBEN Kumamoto Renpeicho
Located in Kumamoto City, Kumamoto Prefecture, LEBEN Kumamoto Renpeicho is certified as a ZEH-M Oriented*condominium. It features outstanding thermal insulation and high-efficiency systems and has obtained third-party certification under the Building-Housing Energy-efficiency Labeling System (BELS) based on the Building Energy Efficiency Act.
While creating a comfortable living environment year-round, this ecological residence conserves energy and reduces utility costs, paving the way for a future of ecological homes that are kind to both the planet and household budgets.
- *ZEH-M Oriented: A Condominium building that significantly reduce energy consumption through high-performance insulation and energy-efficient systems.
LEBEN Oita Ekinan LUXESS
LEBEN Oita Ekinan LUXES, located in Oita City, Oita Prefecture, is certified as ZEH-M Oriented, achieving a roughly 28% reduction in primary energy consumption. It has received the highest five-star rating under BELS. Enhanced insulation, paired with high-efficiency features such as LED lighting, water-saving faucets, and Low-E double glazing, ensures a comfortable and energy-efficient living environment.
LEBEN Toyama Jinzu Hommachi ONE TOWER
Located in Toyama City, Toyama Prefecture, LEBEN Toyama Jinzu Hommachi ONE TOWER is built to meet the high insulation standards required for ZEH-certified condominiums. To ensure thermal performance, insulation has been applied not only to exterior walls and return sections but also to the ceiling. For the window openings, metal-frame sashes and double-layered Low-E glass are used.
Under the Energy Efficiency Performance Standards*, the condominium has received a Grade 4 in the Thermal Insulation Performance Grade—compared to the typical Grade 3 for standard condominiums—and a Grade 5 in the Primary Energy Consumption Grade.
Furthermore, it has received the highest five-star rating under BELS, which evaluates primary energy consumption on a five-point scale.
- * Energy Efficiency Performance Standards: Established by Japan' Ministry of Land, Infrastructure, Transport and Tourism to indicate the energy efficiency of residential buildings.
LEBEN Toyama Nishimachi RESONACIA
LEBEN Toyama Nishimachi RESONACIA, located in Toyama City, Toyama Prefecture, is the first ZEH condominium in the prefecture. It has achieved the highest five-star rating under BELS, which evaluates primary energy consumption on a five-point scale.
The LEBEN Naha Shintoshin Park PREMIST
Located in Naha City, Okinawa Prefecture, The LEBEN Naha Shintoshin Park PREMIST adopts high-efficiency systems and achieves a reduction of over 20% *1 in primary energy consumption for the entire building, including common areas. It is certified as both ZEH-M Oriented and a Low-Carbon Building*2, offering next-generation standards that are environmentally conscious and resident-friendly.
- *1 Comparison with the standard primary energy consumption for heating, cooling, ventilation, lighting, and hot water supply based on the FY2016 energy efficiency performance standards.
- *2 A house recognized by the relevant local authority (such as a prefectural or municipal government) for its efforts to reduce CO₂ emissions and its environmental consciousness.
Net Zero Energy House
LEBEN PLATZ Kazo Hanasaki Park
MIRARTH HOLDINGS group has set the "adoption rate of ZEH-standard in detached houses" as a key performance indicator (KPI), with a target of 100% adoption* in FY2024. LEBEN PLATZ Kazo Hanasaki Park, located in Kazo City, Saitama Prefecture, is a ZEH-standard energy-efficient home that features high-performance insulation and durable materials, as well as double-glazed windows that help maintain indoor comfort throughout both summer and winter. These features improve heating and cooling efficiency, enabling a comfortable living environment while minimizing energy loss. The home is also equipped with excellent earthquake and fire resistance to ensure safety in unforeseen situations.
- *A home certified with a Grade 5 for Thermal Insulation Performance and a Grade 6 for Primary Energy Consumption (excluding the renewable energy level).
CASBEE Certification
The Group is promoting the acquisition of CASBEE * Building (new construction) certification, a comprehensive building environmental performance evaluation system.
- * CASBEE (Comprehensive Assessment System for Built Environment Efficiency): A system for evaluating and rating the environmental performance of buildings. It comprehensively evaluates the quality of buildings, including environmental considerations such as energy conservation and the use of materials and equipment with low environmental impact, as well as indoor comfort and consideration for the landscape.
Office Building L.Biz Matsuyama Ichibancho
Located in Matsuyama City, Ehime Prefecture, L.Biz Matsuyama Ichibancho is scheduled for completion in December 2025 and has received an A Rank rating under CASBEE for Building (New Construction).
The property is also positioned as an advanced facility designed with future ZEB*compliance in mind and is scheduled to obtain ZEB Ready certification. To achieve high thermal insulation, it incorporates enhanced insulation materials and Low-E double glazing, aiming to reduce air-conditioning loads compared to conventional buildings. Indoor air-conditioning units will be equipped with sensors that detect occupancy and floor temperature to improve operational efficiency and energy performance. The building has also been recognized for its energy-saving design, including total heat exchangers with CO₂ sensors and LED lighting with dimming and motion sensors.
- *ZEB: Net Zero Energy Building. A architectural concept aimed at achieving a net-zero annual energy balance by offsetting energy consumption with renewable energy generated on-site.
Rental Residence LUXENA YOGA
LUXENA YOGA, located in Setagaya-ku, Tokyo, has been awarded an A Rank under CASBEE for Building (New Construction).
The building adopts the energy-efficient brand Ecocube, which combines strong energy-saving performance with high thermal insulation. Features such as highly insulated inner sashes, high-efficiency air conditioners, and heat-recovery ventilation fans contribute to an improved indoor environment and reduced utility costs.
In the common areas, a geothermal heat pump system* has been installed to help reduce greenhouse gas emissions. Each private unit is equipped with a heat-exchange ventilation system that continuously supplies fresh air at a temperature close to the indoor environment, ensuring consistent comfort. In addition to these systems, rooftop greening and other sustainable features have been introduced. The building has been recognized for its high environmental performance, achieving both energy efficiency and excellent thermal insulation.
This project has also been approved for a subsidy under the Tokyo Metropolitan Government's "Re-energy Enhancement Project for Local Production for Local Consumption," administered by Tokyo Environmental Public Service Corporation, a public interest incorporated foundation. As of December 7, 2023, it became the first subsidized initiative in Tokyo to utilize geothermal energy in the common areas of a multi-unit residential building.
Heat Pump Specifications
- Model: RWEYP224FAR
- Quantity: 1
- Heating Capacity: 25.0 kW
- Cooling Capacity: 22.4 kW
- * Geothermal heat pump system: A system utilizes the stable underground temperature of 13 to 15°C throughout the year by burying three heat collection pipes, each 95 meters deep, and circulating water through them. In winter, warm water is drawn in, and in summer, cool water is used, enabling greater energy efficiency than conventional air-source systems. Also adopted in the TOKYO SKYTREE, this system is designated in Japan’s Basic Energy Plan as a renewable energy source to be promoted. It is expected to serve as a renewable energy source that supports the transition to a decarbonized society.
Office Building L.Biz NIHONBASHI
Located in Chuo-ku, Tokyo, L.Biz NIHONBASHI enhances indoor environmental quality by controlling thermal loads through the building envelope and managing indoor temperature and lighting. To promote the use of natural energy sources such as solar power, the building ensures sufficient floor height and features a curtain wall*. To help conserve non-renewable water resources, it also adopts water-saving fixtures and implements measures to reduce water consumption.
These environmental features earned high recognition, and this property received an A Rank under CASBEE for Building (New Construction). This is the first office building in our company's series to achieve this rating.
- * Curtain wall: A lightweight exterior wall installed to reduce structural load while providing resistance to external wind pressure and ensuring watertightness.
Achieving Certifications for Managed Properties
MIRARTH Real Estate Advisory and MIRARTH Asset Management actively promote the acquisition of environmental certifications such as DBJ Green Building* and CASBEE at properties for managed properties, as part of our commitment to sustainability in asset management.
- * DBJ Green Building: A program Established by Development Bank of Japan Inc. in April 2011 to evaluates real estate based on environmental and social considerations. Properties are evaluated comprehensively, covering not only environmental performance but also tenant and community engagement, as well as seismic resilience.
Initiatives by MIRARTH Real Estate Advisory
In FY2024, MIRARTH Real Estate Advisory achieved DBJ Green Building recertification for Omiya NSD Building in Saitama City, Saitama Prefecture, with an improved rating from 2 to 3 stars. Hakata Reisencho Building in Fukuoka City, Fukuoka Prefecture, and L.Biz Jimbocho in Chiyoda-ku, Tokyo, received CASBEE S-rank certification.
Initiatives by MIRARTH Asset Management
In FY2024, MIRARTH Asset Management received the highest rank of DBJ Green Building Certification for Royal Parks ER Mandai apartment complex in Niigata City, Niigata Prefecture. This top-tier certification is awarded to properties in Japan that demonstrate exceptional environmental and social considerations.
Environmental Initiatives through ISO 14001 Certification
Environmental Initiatives through ISO 14001 Certification
Recognizing the need to promote environmental friendliness in the general construction industry, Leben Home Build acquired ISO 14001 certification, the international standard for environmental management systems in 2008. We continue to operate our environmental management system by setting and regularly evaluating targets for reducing industrial waste resulting from our production activities at work sites.
- Separate trash at construction sites and promote recycling
- Separate and reduce waste at each business site.
- Regular cleaning outside the company by employees
- Propose plans and designs for energy conservation
Environmentally Friendly Measures
Initiatives at New built-for-sale condominium
Pursuing Low-Carbon Building Certification
MIRARTH HOLDINGS and Takara Leben are advancing the adoption of renewable energy by equipping all new built-for-sale condominiums* with solar panels as a standard feature. Alongside efforts to meet ZEH standards (including ZEH-M Oriented), we are working toward obtaining certification for low-carbon buildings.
A low-carbon building refers to a structure within urbanized areas where effective measures have been implemented to reduce carbon dioxide emissions generated through daily activities. In FY2024, certification was granted for two projects: the "Development of High-Quality Buildings in the Odawara City Sakaemachi 2-Chome Central District" and "THE LEBEN Naha Shintoshin Park PREMIST."
- *Excludes areas subject to heavy or extreme snowfall.
Joint Development of New Services with Resil
To address the growing importance of decarbonization and disaster resilience in new condominium development, Takara Leben has launched a collaboration with Resil, a company driven by the mission to "Make decarbonization less of an intractable problem." Together, we have begun co-developing a new services that enhance disaster preparedness and reduce environmental impact in new built-for-sale condominiums.
Starting in April 2025, Tokyo will require the installation of solar panels and EV charging stations, part of a broader push by national and local governments to tighten regulations and expand tax incentives. Condominium developers must now comply with these new standards. At the same time, the growing intensity of climate-related disasters is increasing the need for in-home evacuation readiness and stronger building-wide resilience, especially in urban areas.
The service enables the supply of virtually 100% renewable electricity to entire new built-for-sale condominiums. It combines renewable energy from a solar power plant to be developed by MIRARTH Energy Solutions with electricity backed by non-fossil fuel certificates. By integrating Resil's expertise in bulk power supply for condominiums and its advanced management of Distributed Energy Resources (DERs), the service delivers "full-building decarbonization."
In addition, the high-voltage collective power system makes it possible to extend solar electricity supply, previously limited to common areas, to individual units as well. In the event of a disaster, DERs can be used to supply emergency power, enabling essential shared facilities such as water pumps, elevators, and mechanical parking systems, to operate through battery storage. This helps maintain residents' living environment and supports quality of life during shelter-in-place situations.
Through this initiative, we contribute to safeguarding residents' essential daily functions during emergencies and to realizing a decarbonized society powered by virtually 100 percent renewable energy.
“nasu mukunone”
Takara Leben opened its own hotel, “nasu mukunone” in April 2024. The hotel’s brand vision is “Relax and unwind in this living and breathing forest,” guests can stay in a vast natural setting of more than 35,000 square meters. On the premises, there is the “MIZUNIWA” designed by an architect Junya Ishigami and “AUBERGE” where you can enjoy local delicacies and elegant relaxation.
At "Nasu Mukunone," natural water nurtured in the lush natural surroundings of the Nasu mountain range is pumped up from underground aquifers and used as "natural water baths" in the semi-open-air baths in the guest rooms under strict quality control.
More than 10 species of wild birds, fireflies, newts, frogs and other rare animals live in the Water Garden, and a Nature Map with explanations of these species is posted inside the building. We will continue to engage in biological conservation activities to coexist in harmony with nature.
Introduction of Hydrogen Vehicle MIRAI
MIRARTH HOLDINGS Group is promoting the introduction of next-generation mobility solutions with low environmental impact as part of its commitment to realizing a decarbonized society.
As one of the initiatives, in December 2024, the Takara Leben Chubu Branch introduced MIRAI, a hydrogen-powered fuel cell electric vehicle (FCEV) manufactured by Toyota Motor Corporation, as a company vehicle. One unit was introduced and is used for daily business operations.
Going forward, the entire Group will continue working to reduce greenhouse gas emissions by introducing clean vehicles that produce no CO₂ during driving.
Promotion of LEDs
For the purpose of effective use of resources and reduction of running costs, we are promoting the replacement of lighting installed in managed properties with LED lighting, which has a longer life and consumes less power.
Measures of Leben Trust
Leben Trust, a real estate leasing and management company, actively proposes environmentally friendly capital investments to owners, such as the use of LED lighting in common areas of managed properties, to promote energy conservation in buildings.
Initiatives by MIRARTH Real Estate Advisory
MIRARTH Real Estate Investment Advisors, which manages the assets of Takara Leben Real Estate Investment Corporation, has implemented LED lighting upgrades in 60 of the properties owned by the corporation.
| Number of properties (including partial installations) |
LED Installation Rate in the Portfolio | ||
|---|---|---|---|
| LED Installation | 60 properties | Total 75.6% | Common areas: 90.2% |
| Private areas: 67.4% | |||
- *Based on floor area, as of the end of February 2025
Environmental Measures in Office Buildings
MIRARTH Real Estate Advisory, which is entrusted with asset management of Takara Leben Real Estate Investment Corporation is promoting environmentally friendly measures to reduce environmental impact and improve indoor environment.
To reduce water consumption in office buildings, we use rainwater for toilet flushing water, conduct awareness raising activities for tenants, and install "water-saving panels" to reduce the amount of water used in the water supply.
In addition, by displaying educational posters in common areas and tenants' private areas, we are promoting the reduction of greenhouse gas emissions and waste by fostering awareness of electricity conservation and the 3Rs.
Regular Cleaning Using Environmentally Friendly Detergents
As part of its commitment to environmental friendliness in condominium management services, Leben Community has officially introduced biodegradable plant-derived surfactants since FY2022.
Although vegetable-based detergents had been introduced on a trial basis at some properties since FY2021, the vegetable-based detergents at that time had less cleaning power than conventional detergents and did not meet the quality required for the services. After a number of trials and errors, we have officially introduced a detergent that does not fall under the PRTR system* and that takes environmental recycling into consideration. Currently, the detergent is used at sites where cleaning and janitorial staff belonging to Leben Community work.
- * PRTR system: A system under which business operators are required to monitor and report to the government the amount of chemical substances released into the environment (air, water, and soil) from their business sites and the amount transferred out of their business sites in waste materials, which may be harmful to human health or the ecosystem.
