SMA x ECO TOWN Harumidai (sales completed)

Community development

Daiwa House Group's community development case studies

Japan's first, next-generation Net-Zero Energy community
SMA x ECO TOWN Harumidai (sales completed)

Sakai City, Osaka Prefecture

"SMA x ECO TOWN Harumidai" was birthed in Senboku New Town, Sakai City, Osaka Prefecture. It is the first (*) Net-Zero Energy community in Japan that we have worked on as the Daiwa House Group.

  1. * According to Daiwa House Industry
  • Development area: 16,832.44 m²
  • Total units: 65 Single-family houses, 1 meeting hall

Development background

In 2011, Sakai City which is an environmental model city, had selected our company as the best proposal, aimed at realizing a low-carbon society, for the "Harumidai Eco Model Town Creation Project".
At that time, environmental problems such as climate change caused by global warming and biodiversity conservation, and power shortage caused by the Great East Japan Earthquake became a social issue, and Sakai City, as an environmental model city, was in a position to reform citizen's awareness as well as promote a change in lifestyle.
Therefore, the requirement from Sakai City for the proposal was [1] to create a house that was environmentally friendly, with comforting living environment and living space that enables high quality of life as well as low carbon town block, [2] to establish an environmentally friendly lifestyle, [3] to present an attractive town that will be the model for Senboku New Town regeneration, and [4] to contribute to the progress of environmental technology. In addition, the houses that were constructed were required to be ZEH (*).
Daiwa House Industry had previously launched the "Smart xevo Eco Project" to realize energy self-sufficiency housing in 2020, and this approach matched the requirements Sakai City sought. We began developing this as a field that could fully demonstrate our technical capabilities.

* Net zero energy houses where primary energy consumption per year is almost zero.

Countermeasure and response to disasters

Introduce facilities to secure electricity and water in houses and public facilities

We installed a photovoltaic power generation system and lithium-ion storage battery (POWER iE6) in all houses, securing electricity in case of disaster. We also have a rainwater tank which secures water for miscellaneous use.
A photovoltaic power generation system of about 19.6kW was installed at the meeting place which is a public facility in the town and the upper part of the adjustment pond which is public infrastructure. At the meeting place, we installed a 14.7kWh lithium-ion storage battery for supplying electricity to the meeting place during power outages. Furthermore, at the meeting place, it is possible to supply power from carsharing electric vehicles parked in the designated parking spaces, and as a result all these provide multiple power backup functions for the meeting place so that it can be used as a center of activity for the town in the event of a disaster.
The meeting place is also equipped with a furnace bench and a toilet bench so that it can be used in a disaster.

Daiwa Lease Co., Ltd. carries out management assistance for carsharing electric vehicles.

About the 17kW photovoltaic power generation system located at the upper part of the adjustment pond About the 17kW photovoltaic power generation system located at the upper part of the adjustment pond

Formation and maintenance of a comfortable space

Preliminarily planned green landscape and underground utility lines

In order to create a good landscape, it was planned so that the neighboring woodland could be seen from within the city. In addition, with all the wires and utility poles set underground, the townscape is very scenic.
Regarding the plants at the public parts and a section of the plants at the residences, the administrative corporation carries out all the periodic pruning, fertilization and disinfection. We are building a structure that can maintain an abundant green landscape.

Fujita Corporation (former: Daiwa Odakyu Construction Co., Ltd.) is in charge of work on underground electric wires and SEIBU Landscape Co., Ltd. is in charge of the town's planting management.

"SMA x ECO TOWN Harumidai", beautiful townscape with no utility poles or electrical wiring "SMA x ECO TOWN Harumidai", beautiful townscape with no utility poles or electrical wiring

Communication between people and people

Promote community activities among residents

All residents have formed a neighborhood association and an administrative corporation. The officials hold a monthly meeting as well as a general meeting once a year for the administrative corporation. There, they are engaged in activities that lead to the decision-making on maintaining and managing the common property of the town, and promoting community formation. In this way, the residents act together to operate the town, leading to a deeper connection between the residents. Recently the residents have been voluntarily planning events and creating various circles, leading to a better community.

The management of events at the administrative corporation is supported by Daiwa LifeNext Co., Ltd.

Cooking event using the "furnace bench" Cooking event using the "furnace bench"

Community independence

Administrative corporation realizing independent management

Inheriting the history of Sakai City which prospered as a free city, the residents have formed the administrative corporation so that the town can be managed independently.
However, the challenge in sustaining an organization such as this is how to cover the costs associated with the operation.
The electricity generated by the photovoltaic power generation system installed in the common area of the town is used in common areas, and the remaining power is sold to electric power companies. In addition, the administrative corporation owns car-sharing electric vehicles, and collects a usage fee when they are used. Revenues earned from this selling of power and collection of usage fees are used for the maintenance of the town as income for the administrative corporation, aiming to reduce the operating expenses borne by the residents, and thus, enabling a sustainable town operation.

The administrative management of the administrative corporation is entrusted to Daiwa LifeNext Co., Ltd.

A meeting of the administrative corporation A meeting of the administrative corporation

Efficient use of energy

Utilization of energy by power generation, storage and HEMS

We also introduced a photovoltaic power generation system and lithium-ion storage batteries at the common areas of the town at the same time as all the detached houses, utilizing renewable energy and shifting the peak of energy. In addition, HEMS is installed in each house, realizing energy visualization. We gather these data to visualize the energy situation of the entire town and rank their contribution towards energy conservation, raising residents’ awareness towards the environment.
In addition, the town owns the electric vehicles as a shared property, enabling car-sharing among all the residents. The electric vehicles are charged using the electricity generated by the photovoltaic power generation system installed in the common area of the town.

Stationary household lithium-ion storage battery (POWER iE6) that can be connected to the energy grid is developed by ELIIY Power Co., Ltd.

"SMA x ECO Cloud" which enables visualization of the energy of the whole town "SMA x ECO Cloud" which enables visualization of the energy of the whole town

Owner's voice

  • I was not conscious of the fact that this was a smart house at the time of purchase. But after living here the result is, that it was a good choice. In reality, the electricity bill has decreased. If we had ordered a house to be built, there would have been restrictions in budget and we would not have been able to install everything to this extent by ourselves.
  • For example, I am now selecting the time to use electricity, like heating water from 11pm onwards when the rate is lower. Because it is easy to confirm power consumption, I frequently check the HEMS. When I come home from work I feel like "Hey photovoltaic power station, you put in a good day's work".
  • I also like the fact that there are no utility poles in the streets, the roads are wide and there is a beautiful townscape. Children have started to want to play outside. I’m thinking about installing a wood deck in my garden.

Administrator's voice

With this "SMA x ECO TOWN Harumidai" as a model, we hope to demonstrate the reduction of CO2 emissions associated with energy consumption in the household sector and to spread the results to other areas. This town is one of the models of Senboku New Town revitalization. We hope that a new lifestyle will spread from here towards the future, including a low- carbon town that raises the quality of life, and lifestyles that are environmentally friendly.

Daiwa House's voice

"SMA x ECO TOWN Harumidai" has received a variety of awards since its birth and received high praise. We have already had about 1000 people visit the site, and are delighted to be picked up in various media.
The goal of achieving a Net-Zero Energy community has been successful for the past 3 years (FY2013-2015). We will continue to check the energy situation every year and verify the changes against the coming years.
In addition, the town has just started to operate. In order to maintain the town for decades to come, we hope that the residents will be the main entity that works on managing the town.
We will continue developing the technology and the experience cultivated with "SMA x ECO TOWN Harumidai", provide new values to local people and communities, and continue making progress so that these values can be maintained for the future.



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