Protecting the precious environment
Energy & CO2

We are working on reduction of CO2 emissions in an effort to create a low-carbon society.

Reduce CO2 emissions in the construction stage

CO2 emissions

In order to reduce CO2 emissions in the construction stage, we are rigidly enforcing the prevention of vehicle idling and appropriate maintenance of construction machinery and vehicles, etc. at each construction site.

CO2 emissions per unit of net sales in fiscal 2019 totaled 9.87t-CO2/hundred million yen, an increase of 0.34t-CO2/hundred million yen a decrease of 0.34t-CO2/hundred million yen (3%)

CO2排出量の推移 グラフ

Reducing CO2 based on industrial waste disposal contractor designation system

Industrial waste generated at construction sites are separated by item (e.g., wood waste, waste plastics, mixed waste) and disposed of by designated companies. Among them, mixed waste has been substantially reduced but are generated over a long period of time from commencement of construction to completion at the site.

From among 6 designated companies and 12 plants in the Tokyo region and 6 designated companies and 8 plants in the Kansai region, we select a disposal contractor that is close to the site and thereby reduce the waste transportation distance, which translates into improved waste collection and transportation efficiency as well as lower CO2emissions.

Reducing CO2 through effective on-site use of soil generated from construction

Nearly approx. 90% of CO2 emissions generated at construction sites is attributable to the use of light oil, so the usage of light oil substantially affects the reduction of CO2 emissions.

In recent years, soil landfill sites have become further away, so CO2 emissions generated during soil transportation tend to increase.

At construction sites, we use the soil generated from excavating works as backfill soil on the site to the greatest extent possible in an effort to reduce the number of dump trucks carrying the soil outside the site and thus reduce CO2 emissions.

Most of the surplus construction soil carried outside the construction site is disposed of in the form of landfills, which may cause the destruction of the environment. Reducing the transportation volume of surplus soil will also help protect the environment.

Brillia City Mitaka Construction Project (Tokyo area)

Approximately 1,000 m3 of the 15,800 m3 of excavated soil generated from root cutting work is stored within the construction site. Even during the temporary storing, we steadily implemented measures to prevent dust from scattering into the neighborhood through sheet curing, and used them in successive backfilling according to the progress of construction.

We reduced the number of dump trucks carrying the soil outside the site by effectively utilizing the soil within the construction site and achieved a reduction in CO2 emissions of approximately 26.5 t.

Measures to prevent scattering of temporarily stored soil

M’s City Shin-Anjo BRANCHERA Construction Project (Kansai area)

The excavated soil generated by the root cutting work was approximately 3,100 m3, and the soil temporarily stored in the site is reused as backfill soil around the foundation (approximately 1,200 m3). During temporary storage and backfilling, we also gave consideration to prevention of scattering of dust into the neighborhood. We reduced the number of dump trucks carrying the soil outside the site by reusing temporarily stored soil as backfilling soil, achieving a reduction in CO2 emissions of approximately 6.3t.

Measures to prevent scattering of temporarily stored soil

Reducing rainforest-sourced materials and environmental burden

Plywood for concrete formwork is made of materials sourced from rainforests. Loss of vast rainforests means losing a huge CO2 absorber, so there is an urgent need to preserve them also from the viewpoint of biodiversity.

Construction divisions have been promoting the use of precast concrete material in hallway and balcony balustrades and ends, decorative columns, outside staircases and floorboards, while adopting the ALC construction method for non-bearing walls. In addition, the construction divisions have been reducing plywood for formwork made of rainforest-sourced materials through such efforts as adopting steel forms and even plastic forms where feasible. In fiscal 2019, use of rainforest-sourced materials was reduced by 562,480 square meters (reduction rate: 40%) in the Tokyo region and by 166,919 square meters (reduction rate: 33%) in the Kansai region.

Use of industrial products and alternative forms in place of wood forms has also reduced offcuts generated at the time of processing, as well as the number of concrete mixer trucks, translating into lower volumes of wood chips and CO2 emissions.

PCa slab for private area
Parapet on rooftop

Identifying CO2 emissions in large-scale repair work

As shown in the following table, Haseko Reform, Inc. measured CO2 emissions at large-scale repair worksites, which revealed that total CO2 emissions increased 46% year-on-year to 213.71t at 130 sites where works were completed for contracts worth 50 million yen or more (79 sites in Tokyo and 51 sites in Kansai).

Meanwhile, CO2 emissions increased in terms of emissions per unit of net sales, growing 19% year-on-year to 0.99t-CO2, due in part to the impact of the increase in properties amounting to no more than 50 million yen and the increase in properties subject to large-scale repair works, in addition to electricity usage, light oil usage, etc. in super high-rise condominiums, mast climbing work platforms, etc. slightly increasing compared to 2018 levels.

Most of the surplus construction soil carried outside the construction site is disposed of in the form of landfills, which may cause the destruction of the environment. Reducing the transportation volume of surplus soil will also help protect the environment.

Identifying CO2 emissions (Contract amount is the total amount of the relevant site's portion)

Company-wide FY2015
(116 sites)
(124 sites)
(100 sites)
(113 sites)
(130 sites)
Total CO2
Total CO2
Total CO2
Total CO2
Total CO2
Electricity usage 273,834kWh 91.89
371,488kWh 128.38
227,736kWh 84.49
223,977kWh 118.29
381,482kWh 128.54
Light oil usage 19,121ℓ 50.56
47,007ℓ 124.3
17,246ℓ 45.6
18,295ℓ 27.69
19,951ℓ 85.17
Waste discharged 2,759t - 1,889t - 2,020t - 1,378t - 3,309t -
Total CO2 - 142.45
- 252.68
- 130.09
- 145.98
- 213.71
Contract amount 195.0million 191.16million 171.28million 176.5million 213.8million
CO2 emissions per unit of net sales 0.73

Environment-Conscious Initiatives at the Design Stage

Utilizing CO2 Emissions Calculation Sheet

In April 2017, we revised Haseko Corporation’s proprietary “CO2 Emissions Calculation Program,” which we had continued to operate since its development in 2011. Based on the revision, we began calculating the CO2 reduction rate based on the “CO2 Emissions Calculation Sheet” using the figures calculated in accordance with the Act on the Improvement of Energy Consumption Performance of Buildings. We have been implementing the revised program since then.

In fiscal 2019, we set CO2 reduction rate of 10% or higher (compared to the standard value under the Act on the Improvement of Energy Consumption Performance of Buildings scheduled to become mandatory in 2020) as our numerical target and implemented it in 93 projects of condominiums designed between April 2019 and March 2020 (68 projects in the Tokyo region and 25 projects in the Kansai region).

Tokyo region Kansai region
CO2 reduction volume (FY2019) 4,091-CO2/year 1,197t-CO2/year
Standard value under Act on the Improvement of Energy Consumption Performance of Buildings CO2 reduction rate 11.1% 11.3%

* The CO2 Emissions Calculation Sheet is a sheet for computing the CO2 reduction rate by converting the standard value and the design value of primary energy consumption of condominium unit areas and communal areas calculated with respect to each project using a Web program in accordance with the Act on the Improvement of Energy Consumption Performance of Buildings into CO2 emissions (t-CO2/year).

Promotion of wood use in construction of condominiums

In recent years, the effective use of domestic forest resources has been drawing attention as part of efforts to build a sustainable social environment, and moreover, the mental relaxation effect of the warmth of wood we have long been familiar with has been re-evaluated.

We have established the Working Group for Wood Utilization and are promoting wood utilization for communal buildings in condominiums as the first step in an effort to use more wood for the main structure of condominiums as appropriate.

In order to meet the diversifying needs including from the projects of our Group, we created the Handbook for Planning and Design of Wooden Communal Buildings to accumulate design and construction know-how on wooden buildings and to add to the menus for proposals for planning and design. This handbook summarizes important points in planning a wooden communal building in the form of a “Planning and Design Flow Chart.” By advancing planning in accordance with the flow and instructions, we are able to plan rationally wooden communal buildings.

Furthermore, for ComRezi Akabane project (to be completed at the end of January 2022, scheduled for delivery at the end of February of the same year), we plan to create wooden common living spaces on the second to fifth floors of its academic residence building. Going forward, we plan to work to develop each element technology with the aim of accumulating multilayered wood construction technology.

RENAI Yokohama Totsuka: Conceptual CG of the communal building
ComRezi Akabane: Conceptual CG of the common living space of the academic residence building

Energy-saving activities conducted by all companies in the Group

Following the revised Act on Rationalizing Energy Use coming into effect in April 2010, the Haseko Group has been engaging in energy-saving activities at its offices by bringing together all companies in the Group.

Energy Usage and CO2 Emissions in Offices

Based on ISO 14001 and the Group Environment Committee, the Haseko Group is promoting energy-saving efforts in offices centered around the Office Working Group (WG) activities.

In the Office WG activities, we focus on the amount of energy use for air conditioning, lighting, and office automation equipment that account for the majority of energy expenditure in our office buildings, and we engage in power-saving activities systematically by designating a person in charge at each floor of Shiba Head Office Building and Hiranomachi Building, offices, and branches with the General Affairs Department and Osaka General Affairs Department serving as the secretariat.

In summer and winter, when office power consumption increases, we set up a special period for power-saving. In addition to responding to the Cool Biz and Warm Biz initiatives officially promoted by the Ministry of the Environment, we are actively promoting actions such as setting appropriate air conditioning temperatures and turning off lights during lunch breaks in unoccupied areas. We worked to reduce power consumption by aggregating the actual results against our fiscal 2019 target of “below the fiscal 2011 actual value per square meter of floor space” to make progress visible every month, in principle, and to inform the sites that failed to achieve the target. Consequently, in fiscal 2019, we achieved a reduction in energy usage (total usage and energy usage per square meter of floor space) and CO2 emissions compared to the previous year.


Reduction of CO2 by Donating PET Bottle Caps

The Haseko Group donates PET bottle caps as a part of its daily ecological activities. In fiscal 2019, we collected PET bottle caps equivalent to 755 kg from our offices and construction sites and donated them to the Minato Ward Recycle Business Cooperative.

This contributed to the reduction of CO2 emissions resulting from incinerating PET bottle caps by 2,378.4 kg.

Registered as a Supporter of “COOL CHOICE” Campaign Promoted by the Ministry of the Environment

The Haseko Group is registered as a supporter of “COOL CHOICE,” a national movement promoted by the Ministry of the Environment.

Within the Group, we disseminate information to make “smart choices” for measures to prevent global warming, with the aim of enabling each employee to choose actions in their daily lives.

Source: The Ministry of the Environment’s COOL CHOICE website

Development of Technology That Reduces Environmental Burdens

Development of “H-BA Concrete,” an Environment-Conscious Concrete

The Global Warming Prevention Plan decided by the Cabinet in accordance with the Paris Agreement calls for expanding the use of blended cement as a way to reduce non-energy-derived CO2 emissions generated by incinerating waste.

Blended cement substitutes concrete admixture such as blast furnace slags and fly ash for a portion of cement, which can reduce CO2 emissions derived from the raw materials of concrete.

We use 225,000 m3/year of typical blended cement called blast furnace cement type-B, mainly as pile concrete for building. To further apply the blended cement, we have developed “H-BA concrete,” which is Haseko’s environment-conscious concrete. H-BA concrete has the same performance as ordinary concrete and at the same time it can reduce CO2 emissions derived from concrete materials. It is produced by mixing ordinary Portland cement with blast furnace cement type-B.

Although its reduction effect of CO2 emissions per cubic meter is limited, it is applicable to all parts of buildings, including ground structures, and therefore it has the advantage of offering versatility as a substitute for ordinary concrete.

The construction of Haseko Technical Center (Tama City, Tokyo, completed in October 2018) achieved to reduce CO2 emissions by approximately 5,800 kg by applying about 125 m3 of H-BA concrete to exterior porch decks.

In the future, we will also develop an environment-conscious concrete for underground structures, which is highly effective in reducing CO2 emissions. Then we strive for the establishment of an operation system in which appropriate environment-conscious concrete including H-BA concrete is effectively used for the right place of structures.

・There are three types of H-BA concrete (H-BA10, H-BA15, and H-BA20) depending on the blending rate of cement.
・ Amount of CO2 reduced when H-BA concrete is used for 100%, 50%, or 30% of our total concrete use (1,739,000 m3/year)

H-BA concrete application at the Haseko Technical Center

Development of Support Tools for Energy-Saving Performance Calculation

We have developed an energy-saving calculation system which is linked to BIM (Building Information Modeling) data. We make notifications in accordance with the Act on the Improvement of Energy Consumption Performance of Buildings and examine thermal insulation specifications using this system. We developed a tool with the aim of further labor saving through automation of calculation as well as visualization of calculation results and launched it at design divisions in the East and West Japan in January 2020. The operation of this tool has enabled a 50% reduction in work hours and a reduction in input errors through automated calculations. We will use these technologies to promote optimal design that meets energy-saving performance requirements.

Biodiversity conservation activities

Conservation Activities

The Haseko Group conducted the following biodiversity conservation activities.

Dates Region Description of activities Number of participants
Activities in fiscal 2019
Nov. 30 (Sat.) Kansai Kyosei no Mori tree-planting activities 86 (including 11 children)
Nov. 16 (Sat.) Tokyo TOKYO GREEN SHIP ACTION Kiyose Matsuyama Green Area preservation activities 58 (including 12 children)
Oct. 26 (Sat.) Tokai Fujimae-higata Cleaning Mission in Fall 44 (including 2 children)
Oct. 5 (Sat.) Tokyo Fifth “Haseko no Mori (Tateshina)” afforestation activities 82 (including 13 children)
Jun. 1 (Sat.) Kansai Second “Haseko no Mori (Shirahama)” afforestation activities 75 (including 6 children)
May. 25 (Sat.) Tokyo TOKYO GREEN SHIP ACTION Hachioji Takiyama satoyama preservation activities 56 (including 11 children)
May. 18 (Sat.) Tokai Fujimae-higata Cleaning Mission in Spring 50 (including 5 children)