Insulating without losing height

The figure that stops most projects

To reach a high thermal resistance, traditional insulation needs several tens of centimetres. Under a ceiling two metres fifty high, that thickness brings the room down to a height nobody accepts, and the project stops there.

What the rule says

Ceiling height governs whether a room counts as habitable, and practice commonly takes two metres twenty as the lower threshold. Going below turns a bedroom into an ancillary space, which affects the value of the property as much as comfort.

The reasoning to change

Thick insulation slows conduction, reflective insulation acts on radiation. They are two different transfer mechanisms, and the second needs no thickness to work, only a properly closed air gap.

What that gives in centimetres

Thirteen millimetres of product, plus the air gap the system provides for. The whole fits in the plenum of a stretch ceiling or a light suspended ceiling, without lowering the finished level any more than decoration alone would have.

The honest trade-off

A reflector does not replace thick insulation in every situation. It excels where the exchange is radiant and where thickness is impossible, which describes a ceiling in renovation exactly.

The case of lofts

Where there is room above, the question does not arise in the same way and added thickness remains relevant. It is in renovation from inside, with no access to the loft, that the height constraint becomes decisive.

The comparison is developed on the thick and thin insulation page, and the product on its data sheet.