I will try to stick purely with building function in this post with the building's primary function being to create an artificial environment at room temperature, about 30% relative humidity and with fresh-smelling air. Also note that the lettered items only apply to the individual posts and not the whole thread.
1) need less:
a) A camping trailer has a small heater and almost no insulation but still heats up fine simply by being so small. We have to learn how to build more compact homes and how to enjoy such homes.
b) hallways and storage areas need to be heated or cooled less then rooms that people actually stay in. These areas can be located along outside walls and for cooling-dominate homes, the south and west sides or for heating-dominate homes, the north and east sides (or west side if temperature swings are an issue).
c) timed thermostats and occupancy testing thermostats can be used to only use heating and cooling when there is actually someone in the room to enjoy it.
d) zoned heating and cooling can single out certain rooms to be controlled or change the rate of control for rooms such as a kitchen compared to a bedroom.
e) if a heating or cooling system is needed, make sure it is the smallest size that will do the job or even too small with a back-up option because these units are most efficient when running at maximum.
2) use less:
a) keep the heat or cool in the house with air-tight design (including air-tight between floors to stop "stack effect" and between rooms to stop wind-powered flow through a house)
b) keep the heat or cool in the house with higher levels of insulation
c) use ventilation systems with heat exchangers to keep the heat or cool in the house while still allowing for fresh air. Ventilation systems can also reduce air pressures on walls that force air through the walls. By putting separate heat exchangers in each floor or even each room, pressures like "stack effect" and wind can eliminated making for much higher efficiency. Occupancy testing can also be used to decide when to turn on fans for more fresh air.
***at this point, I go to #3 and #4 if I want to be energy self-sufficient before returning to the following #2 items
d) radiant heating and cooling FEELS more like the desired temperature irregardless of the actual air temperature. The use of radiant heating and cooling usually results in thermostats being set at less use (cooler heating-season settings, warmer cooling-season settings).
e) condensing fuel burning heaters use far less fuel.
f) heat pumps can provide more heating then the energy used. Whether it is used for heating or cooling, heat pumps are far more efficient if they are using a heat sink closer to the desired controlled temperature so "ground source" or "geothermal" heat pumps are the most efficient.
3) Store energy:
a) Some standards like "Passivhaus" make the house so efficient with #1 and #2 items that no heating or cooling systems are needed. If at this point you do need heating or cooling, plot the needs against the available sources of those needs. This may include temperatures found daily or even just temperature swings within a single space. In these cases, heat or cool can be stored for controlling temperature swings or storing night cool for cooling in the day or daily heat for use at night.
b) if the shortfall in heating or cooling spans a year rather then a day, annual heat storage can be the answer. Passive versions of this include partially or completely underground buildings with a buried insulation "umbrella". Active systems can be used too ("active" means the heat/cool transfer fluid such as air or water is pumped) but require storage of either the transferred annually-stored heat or cool on a daily basis (when moved by solar-powered pumping) or store the energy to run the active systems when that energy is made at different times then the use.
c) Active systems like pumps, fans, and controls need high-quality energy so are either operated when high quality energy is available (windy for wind turbines or sunny for solar panels) and the results stored or the high quality energy is stored in forms like batteries, hydrogen fuel cell systems, or pneumatic air pressure storage.
4) Make your own:
a) Passive heating with south-facing windows and passive cooling with ventilation, strategic shading, or growing grass on the roof can usually meet all your energy needs without anything to break down or wear out.
b) Active systems in connection with storage can be powered entirely during the day when solar energy is available or powered by wind when the wind is blowing.
c) renewable fuels can be used such as wood, crop residues or low quality grain, bio-fuels, or dung.
Once you have decided to use an active renewable energy source or a renewable fuel, return to the second part of #2 for better ways of delivering the heat or cool (and continue into #3 for storage options)