That's often called vernacular architecture and it typically innately includes elements of passive solar design. Such building styles were well-suited to local climate with a minimum of energy-intensive cooling or heating because people simply couldn't afford it.

Additionally, we had cultural practices rooted in staying adequately warm or cool without counting on an HVAC system:

Tapestries on castle walls blocked drafts and provided insulation.

A "three dog night" was a night so cold, the upper classes let three of their large hunting dogs sleep with them to stay warm.

Siestas were naps taken during the hottest part of the day in place of working in the heat.

Buildings routinely had windows positioned to create a cross breeze if you opened them.

Windows routinely were positioned to provide adequate light for essential tasks without having to turn on any lights during the day.

Etc.

Now we build some awful little cardboard box and slap an HVAC system on it as if tech makes up for bad design. It doesn't.