Solid wall insulation

Solid wall insulation is very important. The fact that they are solid doesn’t help the walls to keep the heat (or the cold air) into the house, and doesn’t mean comfort or energy efficiency. On the contrary. In terms of insulation, solid walls behave worse than wood frame houses and are responsible for huge energy losses and wastes.

You can insulate solid walls adding a layer or insulation material to their outside or to their internal side. See: Internal vs. External Solid Insulation

New homes

Do not forget a basic principle concerning home insulation: do it rightly the first time. Costs will be much lower.

To insulate masonry or concrete block walls during new construction you may insulate the block cores with a proper material: plastic foam, vermiculite and perlite are common solutions. But you should also install a thin batt of insulation material between the blocks and the stucco (or other finishing material).

See: Exterior vs. Interior Solid Walls Insulation and Materials for Solid Walls Insulation

Solid walls and climate

The insulation of solid walls is more advantageous in cold climates. But in hot climates with high cooling demands – including regions like the southern United States, where solid block wall construction is very common… -, solid wall insulation is also a key element for energy-efficiency and savings. The problem with insulation, in these cases, and particularly in the case of existing homes, is its cost.

Costs

Solid wall insulation of existing homes is an expensive task - besides being rather disturbing, namely the internal insulation. Due to these reasons, homeowners use to install insulation when the walls demand re-siding, painting or other repair work. That may reduce insulation costs by 40 or 50%.

In other words, if your home needs a new painting and stuccoing, the cost of insulation becomes more attractive, but involving amounts of at least $1,500-$2,000 (without considering the stuccoing and other costs).

Contractors

Skilled Do-It-Yourselfers may carry out interior wall insulation, but adding insulation to the outside of a house requires a professional contractor, with specific equipment and knowledge.