Masonry Magazine March 1963 Page. 4
The Economics and Sense of Insulating Masonry Walls
by Clayford T. Grimm, P. E.
This article is based on a paper titled "The Economics of Building Enclosures" presented by Grimm at the 1961 Fall Conference of the Building Research Institute, then a part of the National Academy of Sciences National Research Council. A method for the rapid determination of annual fuel costs attributed to heat transfer through masonry walls is provided, including heating and air conditioning costs. The study is applicable to smaller projects. It is shown that, aside from reducing operating costs, the addition of insulation can in some cases reduce the size of mechanical equipment by an amount sufficient to pay for the entire cost of insulating. The insulation of masonry walls provides masonry contractors with an additional profit opportunity.
The engineering properties of most materials are well known, and architects have devoted a substantial amount of study to aesthetics. But economics, once you leave the familiar ground of initial costs, is often a mysterious and uncharted bog.
This is not to say that building industry professionals lack awareness of this condition. No less authoritative document than the AIA Handbook of Architectural Practice demands that a building be designed for "efficient operation and economical maintenance," and the materials employed be "economical for their particular use." This consideration of economics extends to the cost of owning the building rather than simply putting it up. To put it another way, this implies searching for the ultimate cost of buildings over their useful life in contrast to what is sometimes a comparably minor expense of putting a roof over a client's head.
It is not sufficient that men or buildings be handsome and strong; they must also earn their way in the world, support dependents, stockholders, and families. Profit is the prime reason for enclosing rentable space, and lower total cost consistent with the use of the building is always desirable to free funds for other needs.
Insulation of building enclosures affords an excellent opportunity for a study of comparative economics because the monetary saving it provides is the principal reason for the use of insulation, though increased comfort is also a consideration. In 1961, inadequate insulation cost this nation nearly $2 billion in wasted fuel. A greater emphasis on the economic performance of building materials is a necessity not only for the benefit of the building owner, but of the nation as a whole. Hunch and guesswork must be eliminated from the selection of building materials. This will be accomplished only when more emphasis is placed on building economics.
Generally, masonry walls have not in the past been insulated, perhaps for these reasons: (a) Lack of general recognition of the magnitude of monetary savings achieved by insulation; (b) The high initial cost of insulation of walls (25c or more per sq. ft. for 2 in. in place); (c) The inability to place rigid or batt insulations in unfurred masonry walls; (d) The lack of adequate fill-type insulations; (e) The mistaken belief that since so much heat is transferred through glass, it makes little difference how much goes through opaque areas.
While there is a germ of truth in each of these contentions, they are either no longer valid or they lead to false conclusions. It is hoped that the data presented here will lead to a greater understanding of the magnitude of savings which insulation can achieve.
The other objections may be met as follows: The cost of insulating masonry walls is less than half as much today as it was five years ago. Water repellent vermiculite masonry fill insulation for the cores and cavities of unfurred masonry walls is now available. Its use was described at the Building Research Institute Conference on Insulated Masonry Cavity Walls, the proceedings of which are available as BRI Publication 793.
It is true that heat loss through glass is typically 100 to 400 per cent greater than through walls. However, heat, and therefore money, is lost through opaque areas in considerable quantities. That loss can be greatly reduced by insulation. To argue that large glass areas eliminate or reduce the need for insulating opaque areas in the same building is like saying, "I'm losing so much money now a much greater loss won't make me any worse." On the contrary, large glass areas make the use of wall insulation even more compelling.
Aside from reducing operating costs, the addition of insulation can in some cases reduce the size of mechanical equipment by an amount sufficient to pay for the