Our insulation liner consists of 2 separate layers – a double reflective bubble wrap layer that is pulled over top of the frame, and underneath the outer cover – and an inner fabric liner that creates an additional air pocket to help with insulation. The way the reflective layer works is that it will reflect heat back into the space, aided by the spherical, very energy efficient shape of the dome. This will result in about an R5 overall. However, it will not hold heat for very long after the heat source is out – for this you would need several inches of insulation material.
Many of our customers operate year round with our insulation package and good stoves.
For a permanent structure, you can get the inside of your dome sprayfoamed by a local company to achieve a much higher R-Value more similar to a cabin or house while also eliminating any thermal bridging or condensation on the frame – but it means that the dome cannot be taken down easily anymore. The sprayfoam can then still be covered with the inner fabric liner.