With the rapid development of national economy and continuous innovation of construction technology, the old housing are subject to the age of construction, its construction concept, construction technology, building materials selected is relatively backward, especially the energy saving effect is poor, which increased the energy consumption. The article mainly studies the wall structure,  roof, Doors and windows insulation, Heating and ventilation of the old housing, systematically analyzes the main reason for the excessive energy consumption of old housing and puts forward the countermeasures for the reconstruction of buildings on the basis of analysis above.

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