Fig. 7 Small yard ⑤
The adoption of building layout strategies, especially orientation, causes low or even no additional building cost. It is a cost effective energy saving strategy which tremendously reduces the resistance to its application in building industry.
2.Envelope thermal physics involves application of insulation and thermal storage materials to reduce heat transfer through the walls, roof, windows and subsequently the air conditioning load.
Typical passive solution:
  1. Double skin facade(DSF):can efficiently reduce the overall HVAC consumption in buildings by absorbing part of the solar radiation during winter and preventing overheating during warm periods. The DSF can work under different ventilation modes or work as a Trombe wall.[11[] Gracia, Alvaro De, et al. ”Numerical modelling of ventilated facades: A review.” Renewable & Sustainable Energy Reviews 22.22(2013):539-549.](Fig.8)
    Fig. 8 Double skin facade
  2. Mass wall
    Residence in northwest China use vernacular clay to ram into walls. The structure is compact, strong cohesion, and good thermal inertia, making the inner temperature steady. [22[] Cao. Scientific analysis of the energy saving technology of the traditional houses in Northwest China. Diss. Xi’an University Of Architecture And Technology, 2013.](Fig.9)
    Fig. 9 Cave dwelling ⑥
  3. Green roof
    A green roof protects the roof slab from extreme temperatures and high temperature fluctuations. This protection is afforded by a number of thermal phenomena that occur in the green roof, such as solar shading, evapotranspiration, and thermal resistance.[33[] Jaffal, Issa, S. E. Ouldboukhitine, and R. Belarbi. ”A comprehensive study of the impact of green roofs on building energy performance.” Renewable Energy 43(2012):157-164.](Fig.10-11)
    Fig. 10 Effect of green roof
    Fig. 11 Construction of green roof
    The selection of envelope is one of the most effective ways to minimize the energy consumption related to interior thermal comfort.[44[] Kerdan, Iván García, et al. ”An exergoeconomic-based parametric study to examine the effects of active and passive energy retrofit strategies for buildings.” Energy & Buildings 133.2016(2016):155-171.]
3.Building geometry
Building’s geometric form have more impact on a building’s energy performance than materials utilized in the building envelope in some cases.[55[] Hemsath, Timothy L., and K. A. Bandhosseini. ”Sensitivity analysis evaluating basic building geometry’s effect on energy use.” Renewable Energy 76(2015):526-538.] Parameters such as window to wall/ground ratios, window location and solar shadings are classified as building geometry factors influencing natural lighting, ventilation and solar gain.
Residence in south/north usually possess analogous geometry. Aside from culture and historical reasons, energy efficiency and indoor comfort are critical factors attributes to this phenomenon. The geometry is a result of a long evolution process.