For buildings to be efficient at maintaining room tempurature they need thermal insullation, ventilation systems and humidity control. Heating can be free using solar . All these systems already exist, for example: in floor tubes for solar hot water systems for use with existing unit. of course with insulllation. Not rocket science

I have sat in a bus on a warm day and no one opens a single window. However, on a cold day, the first thing they do is open the window as wide as possible. This is because chinese prepare for the cold before they leave the house. They wear 2 sets of thermal underwear and many layers of clothing. By the time they walk to the bus stop, they are suffocating from the heat so they selfishly open the windows to cool themselves off. Since most chinese are slim, it is easy for them to feel the cold so they prepare and wear a lot of layers of clothing. In this particular case, us foreigners need to wear more clothing and forget about trying to get them to close windows because that is an impossible task. I fought that battle and lost.

Especially the women hitting menopause.

Especially the women hitting menopause.

@HFCampo: Perhaps you might prepare for the cold before you leave the house - I've been doing that all my life when I know it's cold outside. I haven't noticed Chinese suffocating from the heat when they arrive at bus stations. But yeah, I've noticed people opening bus windows, or just leaving them open, when I'd prefer they were closed.
When I sit by a window, I open or close it as I please, with some regard for other passengers.

These theories about why Chinese keep windows open are interesting. In Beijing, October 15th is the beginning of the central heating period and it ends on March 15th. As this is a government diktat, actual weather conditions are not important.

This also the period for wearing long underwear and multiple layers.

The Beijing winter of 2002/2003 was cold but the early spring was accompanied by SARS. We were required to keep all windows tightly closed to prevent SARS as this was a TCM solution. Eventually, science triumphed over tradition as it became clear groups of people in tight quarters with little ventilation actually enhanced the likelihood of SARS spreading. Beside, disinfectant was sprayed on all the floors three times a day and the stench was barely bearable.

Most Westerners opened windows and shed winter clothes as temps hit 20 plus in late February. The Chinese followed orders and kept windows closed and bundled up until March 15th.

Eventually, science triumphed over tradition and windows were opened. Oddly, the spraying continued but vinegar replaced expensive and hard to find disinfectant.

So, let's get this straight, in south China they open the windows, due to TCM beliefs about fresh air, but when a real threat (SARS) arrives, TCM said close the windows? I don't get it!

My students sit with their down coats on, zipped right up to their chin, and then beg me to switch the fan on. I say, "If you are hot, unzip your coat a little bit, you fucking moron". Obviously the last 3 words are just in my head

Our Chinese nanny has just insisted our child stay inside as it's too cold outside, and then opened all the windows in the house to let in fresh air. Gotta smile at some of this fine country's traditions!

it's warmer outside in the sun.

yeah, when I went out at about 9pm yesterday evening, it was definitely warmer outside than in my building