Do Outdoor Saunas Need Insulation?

Redwood Outdoors - Jun 22nd 2023

If you're thinking about adding a sauna to your home, one of the most important questions is – are outdoor saunas insulated, and do they need it?

Do Outdoor Saunas Need Insulation?

Mostly, no – installing additional material to insulate a small outdoor sauna is not required. They do, however, typically include and require adequate levels of heat efficiency to allow them to perform well.

Barrel Sauna

Barrel saunas are designed specifically to retain heat and achieve optimal performance without being insulated. Heat retention is maximized thanks to their circular shape, which facilitates natural heat retention and a cycle of rising and falling warm and cool air, respectively.

These also tend to be smaller, with tightly fitted planks and dimensions more favorable for maintaining a high temperature. Plus, rounded rooftops prevent rain and snow from collecting.

Barrel models can also be heat treated, transforming wood surfaces through thermal modification for enhanced efficiency.


The most popular pre-built designs are generally made to retain warm air and prevent unwanted moisture from accumulating without any need to insulate them further.

Since most pre-built and kit-assembly saunas will come already equipped with all that’s needed to maintain a stable temperature, you shouldn’t need to insulate them yourself. So unless you’re building your small outdoor sauna on your own from scratch, you can scratch insulation off your list of concerns.