Designing for Energy Conservation

Designing for Energy Conservation

A good historical reference point for discussing the energy conservation movement in architecture is the Arab Oil Embargo of 1973, which mobilized an extraordinary campaign to conserve energy when heating and cooling buildings. Around that time, most states incorporated performance or prescriptive thermal energy requirements into their states incorporated performance or prescriptive thermal energy requirements into their building codes.

Because of this boom in efficient construction, residential operating costs for energy efficient houses have been reduced to a point of diminishing returns; a passive solar house built today can be designed to consume less energy over the next several decades than was consumed to build it. Consequently, if comparable gains in energy conservation are to be realized over the next 20 years, the focus on savings must now concentrate on embodied energy. Embodied energy is essentially all the other energy (beyond that reflected in operating costs) consumed in the life cycle of a building: harvesting of resources used in the building, manufacturing of

products, transporting of materials from source to site, building technique, and recycling or removal of existing structures.

In addition, all the thermal energy efficiency we've realized has a side effect—efficient buildings may be hazardous to your health. Air infiltration has been greatly reduced in today's residences compared to the houses of 20 years ago; low air infiltration is a key feature of thermal energy efficiency. Off-gassing from many synthetic materials used in today's construction can be trapped within a house much longer today than in the past because houses are not as "leaky" as they used to be. So using nontoxic building materials for healthier indoor air quality is even more essential today than in the past.

In addition to embedded energy considerations and nontoxic materials use, architects also need to allow for the concept of sustainable design. Sustainable design essentially means solving the needs of the present without detracting from the needs of the future by creating architecture that minimizes the use of natural resources, toxic materials, and emissions of waste and pollutants over the life cycle of a building.

The materials used in a sustainably designed structure are known as "green" building materials.

Using green building materials is a responsible approach to the maintenance of human health, conservation of nonrenewable resources, and preservation of the environment for future generations. Ultimately, homeowners, architects, and builders must aspire to such green design.

How much will substituting a green building product for a conventional product cost? This is a reasonable question, but when a client asks the builder, the typical response is often: "Any deviation from standard construction practice will probably increase the cost of your project."

My key focus is standard, "unheroic" residential construction products and materials, such as framing, siding, and flooring materials, rather than the higher-profile "heroic" products such as solar or photovoltaic panels. "Unheroic" materials consume most of the energy and resources of the residential building industry. They are the materials most architects, builders, and homeowners are most familiar with.

Substituting many conventional materials with green building materials would change the course of residential construction. A complementary situation could be created by providing a market for the waste stream, thereby improving the economy and preserving our natural resources and environment for future generations, contributing to a higher standard of living.

The survival of the green building industry depends upon our ability to build with green products. But then again, isn't their survival today really our survival tomorrow? In the final analysis, how can we afford not to use these products? To build for our future means to build it well, build it beautifully, and build it green.

Construction Cost Savings with Green Building Products Not only can green building products be healthier for people and good for the environment, but many green products also are less expensive than the conventional building products they replace. Since many green products are manufactured by small startup companies that can't afford expensive marketing campaigns, they just aren't well known by the construction industry or consumers.

If you're planning a construction project, you may want to consider some of the less expensive green alternatives to conventional products. Why not save on construction costs while building a residence that contributes to your health, well-being, and a cleaner environment?

I have focused on healthy, energy-conserving, and environmentally conscious building materials for residences. Green products can incorporate all of these benefits for added value to clients at a lower cost than their conventional counterparts. The following suggestions describe construction elements for which immediate initial cost savings can be realized by choosing the green product.

Structural and Exterior Products In the construction of site work elements, such as driveways and parking spaces, porous paving products can reduce the cost of asphalt surfacing as well as the need to provide drains. Both porous and nonporous rubber tiles and monolithic nonskid surfacing can be applied to outdoor patio areas and walkways at competitive prices. Decks can be rendered maintenance free with wood/resin composite decking. For landscape irrigation, gray water systems are becoming very competitive. One manufacturer will even match the bid price for any proposed conventional irrigation system.

For typical foundations, fly ash can be added to concrete to increase the strength, thereby reducing the amount of concrete required for a project. A gravel substitute can be used for both foundation drainage as well as septic system absorption fields at a fraction of the material and labor costs of conventional methods.

For the walls of a residence, there are many cost-saving alternatives that are a dramatic departure from conventionally framed walls. Metal framing can be less expensive than wood so long as you select the proper metal fabrication system and a builder experienced with steel framing systems. Polystyrene concrete form systems combine formwork with insulation for structural concrete walls. For concrete block walls, aerated concrete block is a cost-competitive choice. A very effective insulated block wall system that reduces cost compared to conventional block walls with insulation applied is the composite polystyrene/cement block system.

Manufactured stress-skin sandwich panels are the most dramatic departure from residential stick framing while still being cost competitive. If you're still comfortable only with conventional

wood framing or are adding on to an existing residence with wood framing and don't want to change structural systems, try finger-jointed studs, which are straighter and dimensionally more stable at about the same price as single-piece unseasoned studs. For larger beams, recycled lumber is usually less expensive and of a better quality than new wood. With conventional stick framing, be sure to use gypsum wall clips when hanging your drywall for labor and material cost savings as well as better thermal efficiency.

Healthier and more environmentally conscious low-formaldehyde sheathing is the same price as plywood. And where shear requirements are lower, compressed paper sheathing will do the job for less money than plywood.

Various hardboard, fiber-cement, and vinyl siding alternatives and trim offer inexpensive and low-maintenance alternatives to redwood lap siding and trim.

Cellulose insulation (shredded newsprint with boric acid added) is a healthier alternative to the popular fiberglass insulation that has been added to the list of suspected carcinogens. Cellulose insulation is cheaper to install in ceiling cavities than fiberglass insulation but slightly more expensive in walls and floors. For block walls, perlite is much less costly than polystyrene beads for insulating the cavities.

Roofing shingles to choose from include metal, polymer, and processed wood, all of which also include the benefits of low maintenance.

Typically, good quality vinyl windows are less expensive and more energy efficient than good quality wood windows, in addition to being lower maintenance. The newer composite windows are also very competitively priced compared to wood windows and have excellent thermal efficiency ratings. The flexibility and ease of installing light tubes provides a less expensive alternative to conventional skylights.

Interior Products Several flooring products offer an attractive alternative to conventional products such as various types of cork flooring. If you're considering resilient flooring, why not use natural linoleum flooring? It's about the same price as comparable vinyl sheet or tile flooring.

For floor coverings, you may want to consider sisal, coir, jute, or seagrass broadloom and area rugs with latex backing, which can be about the same price as an average nylon carpet. But, if you're in the market for a nylon carpet, one made from 100% recycled plastic can be purchased for only a fraction of the cost of those made with new materials.

Paints offer a wide selection to choose from. If you're interested in ceramic insulating paint for both reducing heat gain and heat loss, it's less expensive per gallon than popular top-quality latex paints. If your main objective is to really save on the initial cost of paint, paint

manufactured from recycled paint is the least expensive. If your emphasis is on indoor air quality, there is also a selection of inexpensive nontoxic paints and sealers to choose from.

Formaldehyde-free composite strawboard offers a healthier alternative to particleboard for cabinet boxes, at about the same price. For decorative features in cabinets, flooring, and moulding, a soybean composite fiberboard is also competitively priced.

When remodeling a bathroom, it is worth considering using a porcelain resurfacing product to repair finishes on bathtubs, sinks, and tile, at only a fraction of the cost of replacing the fixtures.

These are a few ideas for reducing the initial cost of residential construction through the use of green building materials and products. There also are many more valuable green products that offer cost savings on a life cycle basis rather than merely an initial cost, and many of those products will also become less expensive as manufacturing costs come down with larger-scale production capacity.

Source: https://dticorp.com/designing-for-energy-conservation/