The comfort of our home or I would rather say comfort of ourbeing, depends on thermal stability. To maintain the temperature at a stablelevel we would require a material that can store heat. The most common one thatis currently being used is concrete slab and masonry walls. To contribute tothe thermal stability, it would have to be included inside the insulationenvelope and not exposed to the outside environment.
With timber framed homes or modular walls this is limited toconcrete floors on ground for most of the time, but there are other options aswell that can be incorporated into lightweight construction or even existingbuilding.
Just recently I have been looking into phase changingmaterials that can absorb and store large volumes of excess heat during thedaytime hours and to release that same heat at night to warm the structure astemperature drop. This would be very beneficial to prolong the passive heating/coolingperiod inside your home.
It is much more efficient then heavyweight thermal mass withthe ability to change the phase at only 23 deg and would significantly impacton the energy usage of the house. It releases heat without getting cold asopposed to concrete or masonry wall.
With a well-designed home and good placement of thermal massthat can effectively work your home should be able to reduce the need of activeheating or cooling to minimum.
Those videos might be bit lengthy but very informative on the product and great solution also to improve your existing homes with additional thermal mass.