Thermal Mass is often presented as the magic ingredient to ensure that the passive solar gain within a building is maximised, but the importance and usefulness of Thermal Mass can vary depending on the purpose and location of a space, along with glazing and insulation. 

Why is it that single drop 'Thermal Drapes' are considered to be the solution to retaining heat within a house during winter, when lined curtains of ordinary fabrics have been used in the past?

Before worrying about slab-edge, start with thermal bridging fabric above the ground floor with timber floor insulation and appropriate joinery detail.

Last November I wrote of thoughts I have had for a very long time regarding the possibility of there being negatives in fitting thermal insulation to the exterior face of an un-heated slab-on-ground concrete floor.

Shading is a double-edged sword. The varying aspects of shading as broadly defined need to be considered right from the beginning of the design process, due to the significant positive and negative effects it can have on solar gain throughout the cycle of the four seasons.

Inadequate site selection decisions can eventuate in a closing-off of later desirable design options for efficient passive thermal design.

When making design decisions on thermal aspects of building materials and constructions, it is important to put them in perspective to maximise their performance – the inter-relational 'sweet-spot' – without compromising the liveability, aesthetics, buildability and economics of the completed project.

On balance, is there a long-term thermal and economic gain to be had from fitting insulation to the exterior face of a ‘slab-on-ground’ concrete floor... and is it as effective as it seems? 

No matter how high the thermal performance of a window, it remains much less than the same area of a standard insulated wall. With this in mind, it would be wise to give the location of a building's windows careful consideration.

Just like thermal mass, insulation will keep you cold if you do not use it intelligently.