#Energy Efficiency #Japan #Katsushika #ZEH #Sais Corporation

Sais Brings High-Performance ZEH Homes to the Spotlight

On July 28, 2023, the Tokyo Climate Change Adaptation Center visited Sais Corporation, located in Katsushika Ward, Tokyo, to explore their model homes and high-performance ZEH (Net Zero Energy House) offerings. The event was aimed at evaluating energy-efficient housing solutions amid rising electricity costs and increasing heatwaves.

The visit started at Sais's model homes, where staff provided insights on insulation techniques and airtightness. Visitors experienced the comfortable indoor environment firsthand, followed by a presentation from President Tatsuya Oikawa in the company's “Sais Hall.” Oikawa discussed efforts to enhance housing performance and engaged in a dialogue concerning future housing needs that can withstand heatwaves and natural disasters.

Understanding the Importance of Efficient Housing

Due to the rising concerns about heatstroke, the Tokyo government has been promoting the responsible use of air conditioning during summer. However, many residents hesitate to use air conditioning due to worries about utility bills. Hiroyuki Miyata, head of the center, expressed his motivation for selecting Sais by emphasizing the need to enhance insulation, airtightness, and the overall performance of buildings as a countermeasure to heat.

Miyata stated, "Sais's achievements, including having won the 'House of the Year' award nine times, exemplify a significant movement towards popularizing high-performance housing in Tokyo, in collaboration with local authorities."

Innovations in Design and Sustainability

Sais employs the SW (Super Wall) construction method across all their properties, which has achieved a record of zero demolitions during the Great East Japan Earthquake. They've also implemented the use of hybrid water heaters and standard solar power systems in nearly 97% of their newly built homes. Their designs consider limited land conditions while maximizing the installation of solar panels, demonstrating an innovative approach to using space efficiently.

The homes not only achieve a UA value of 0.35, exceeding the G2 standard proposed by HEAT20 but also incorporate intelligent design features to provide bright, airy living spaces without oversaturating with windows. This includes artistic placements of skylights and windows to ensure ample natural light while minimizing excessive heat gain in summer.

Acclaim for High-Performance Housing Initiatives

Sais’s commitment to high-performance housing has been recognized on a national scale, with the firm winning the 'House of the Year' title nine times and consecutively receiving the Leading Company Award at the Tokyo Eco Builders Award for the last three years.

This success is a reflection of Sais's ongoing collaboration with local communities, as demonstrated through their role in the Katsushika Energy Conservation and Renewable Energy Healthy Housing Promotion Liaison Council, aiming to raise awareness and distribute knowledge regarding high-performance homes.

Looking Towards the Future

As stated in Japan's 7th Energy Basic Plan, the government has set ambitious targets for energy efficiency in housing. These goals include ensuring that 60% of new houses built following 2030 adhere to ZEH standards, highlighting the urgent need for decarbonization in the building sector, which accounts for approximately 30% of the nation’s energy consumption.

Founded in 2001, Sais has prided itself on its commitment to pursuing authenticity and excellence. They have gained invaluable insights by visiting leading energy-efficient countries like Germany and Switzerland, and actively disseminate their acquired knowledge through seminars aimed at builders nationwide.

Sais is dedicated to sustaining its infrastructure long-term, maintaining homes through generations, and adapting to their client’s needs, which reflects their enduring mission of protecting families and properties from natural disasters and climate change.

In summary, Sais not only strives to provide high-performance housing but also continues contributing to regional development and environmental sustainability. With their innovative approaches and community engagement, Sais is paving the way for a brighter, more sustainable future in housing.