China Overseas Heshan Daguan-An Ultra-Low Energy Community Practice

The project is in Haoqinying, Xincheng District, Hohhot. The construction land area is 69,500 sqm and the total GFA is 166,500 sqm. This project was all designed and constructed based on the standards of ultra-low energy buildings. 
This project is designed to be a new urban sample of ultra-low energy consumption, green and healthy technology. With all those innovative technical measures, the building energy demand has significantly reduced. This community achieves a 92% building energy-saving rate and balanced comfortable indoor spaces. The project is all equipped with a direct drinking water system, rooftop photovoltaic power station, energy monitoring system, and other systems to enhance the green and healthy attributes of the building. The project achieved a 92% heating energy-saving rate. This has made a pioneering exploration practice to achieve carbon neutrality in the building sector in severe cold regions. The implementation of the project has bridged the gap of large-scale ultra-low energy consumption projects in the severe cold zone in China.  
The breakthrough of the equipment operating under ultra-low temperature environments has an important leading and demonstration significance. The promotion of ultra-low energy building technology not only achieves people's demand for a healthy residential environment, but also improves energy utilization efficiency, reduces energy consumption, reduces pollutant emissions, and plays a positive role in promoting environmental protection, energy conservation, and emission reduction. On the planning level: The layout of the building is organized to create a large central garden from north to south, which is harmoniously integrated with the surrounding environment. The adequate spacing between the residential buildings ensures that the residents have sufficient light, a good landscape view, and abundant activity space. Good planning creates a safe and quiet residential environment. 
The following technologies were mainly applied in the practice project. 
(1) High-performance outer envelope. The thickness of the exterior wall and roof insulation is 2.5 times that of conventional projects, and the heat transfer coefficient of exterior windows is 1.0 W/ sqm-K, which improves the thermal insulation performance of practical ultra-low energy buildings by about 45% compared with traditional buildings. 
(2) Good airtight design. The project uses airtight membranes, mortar, and plaster to strengthen the airtightness of holes and other parts, and the airtightness N50 index of this project is about 40 times better than that of conventional projects. 
(3) Design and construction without thermal bridges. The project applied several construction technology systems such as no thermal bridge construction and convenient construction and installation of embedded passive windows, which achieved good construction results and saved about 10% of construction manpower. 
(4) High-efficiency fresh air system& heating and cooling system. The practice project adopts an Integrated heat pump environment control unit with outdoor air, with a fresh air full heat recovery efficiency of 70%, and the unit guarantees indoor comfortable and healthy environment quality with very little energy consumption. 
(5) Renewable energy utilization. A solar photovoltaic power generation system is installed on the practice roof to generate electricity for the lighting of the underground garage, and the power generation capacity (taking building 1# as an example) is 2.91 kWh/ sqm/a.