The result is the following guide to the best insulation for exterior walls. R-value 13.1 Sika’s Rmax Pro Select board is essentially dense foam insulation for walls in sheet form.

Fitting exterior walls with insulation will reduce heat loss, which in turn should help cut utility bills. Not only can that help keep a home cozy for less, but the reduction in energy consumption is ...

then add new insulation from the outside, new sheathing and metal siding. A Your plan will work, but depending on the current state of exterior walls, it could also involve a lot of unnecessary work.

HVAC systems are widely used to carefully heat and cool homes, but even the most energy efficient systems can largely go to waste without appropriate exterior wall insulation and ceiling insulation.