If the walls are brick veneer over wood framing and you will be doing major indoor remodeling, you could remove the plaster or sheetrock from the interior surfaces of all your exterior walls and fill in the exposed stud cavities with blanket insulation. Or you could drill through the interior wall surface and blow in loose fill cellulose. (You would need to patch the wall surfaces when done.) If neither of these options would work for you, your only other real choice would involve blowing insulation into the wall cavity through holes drilled into the stud wall's top and sole plates. To do this, you would work in the attic and basement or crawl space rather than outside.

If your walls are solid brick, if access to wall plates is blocked by a shallow roof or a slab foundation, or if the cost of installing the insulation is higher than you want to pay, you can take other steps to reduce energy costs and discomfort. These include moving beds and chairs away from exterior walls, sealing air infiltration points, and using shades or drapes to cut heat loss through windows.