Cost-effective green retro-fitting of an existing building.

Don't overlook existing buildings, including historic buildings, when considering retro-fitting to meet new cost-saving "green" design standards.

For retro-fitting to cost-saving "green" design standards, existing and historic buildings may be architecturally challenging, but shouldn't be overlooked.

Because existing buildings have so many pre-existing constraints, owners often don't consider them for "green" re-design, but there are more of them in our urban setting than new buildings. For every new building that comes on-line in the New York area, there are thousands of existing ones whose current owners could benefit financially from newer, more cost-effective green operating standards.

In a practical business sense, my firm uses the term "green" to mean architectural strategies for buildings that increase net profits with a measurable payback of three years or less by providing new sources of revenue or reducing operating expenses. Energy performance is the core value.

Of course, it's important to weigh and consider the advantages and disadvantages of existing buildings or existing historic buildings whose owners or managers desire to transform them to meet modern, green standards.

The architect who takes on such a project must identify and understand those constraints, and then figure out how to weave in money-saving, energy-saving, green ideas, which can be more difficult than designing the same types of efficiencies into a new building.

The first practical step is to understand what are the green design advantages and disadvantages inherent in existing buildings.

Older buildings generally have thicker walls, so they tend to be more insulative and conserve more energy. Older buildings are bulkier and squatter with a more compact architectural plan and are therefore more energy-efficient by nature.

Older buildings were typically designed with oversized equipment and much larger ceiling plans, because they were based on old-tech engineering with fewer motors and controls, so a modern boiler takes up one-fifth of the square footage of an older boiler giving you more flexibility and available space for installing new technology upgrades.

An older building has factual data and a history of energy performance, so that every new efficiency improvement in an older building is measurable and can be compared to past performance.

Another aspect of sustainable design in a retro-fit is lighting efficiency, with a potential changeover to get equivalent or improved illumination, but with less energy usage. Perhaps most important of all from a dollars and cents perspective, every energy efficiency improvement in an older building is measurable and can be compared to past performance.

If you were hiring an architect to do a green cost-efficiency analysis of an existing building, these are the things you'd want to pay attention to.

Windows are the biggest source of energy leaks and waste, especially with single-pane, oversized, drafty windows, which result in infiltration making heating overly costly, inefficient and difficult to control.

The space-consuming footprints of larger, older tech devices limit the space available for installing more modern technologies.

The A/C and ventilation concepts in an existing building are often decades old and totally antiquated, and bear no resemblance to parts or components manufactured today, so that when one module fails, it's typically necessary to replace the entire system, which can be very expensive.

High level finishes, such as beautiful floors and plaster walls, and highly decorated ceilings with gorgeous light fixtures and air-registers make it very expensive to disturb any of them for tech retro-fitting, whereas in a new building you can cut in nearly anywhere, at will, at limited expense.

Historic buildings sometimes have many fireplaces, which are popular again, but conflict with modern HVAC systems wasting costly energy.

And, cultural changes related to water, whether it's grey water, waste water or clean water, challenge today's architects to identify recycling savings opportunities such as capturing and re-directing grey water for reuse. To address the green retro-fitting process in realistic business terms, my firm says to a facilities manager, give us your capital expense program, give us a list of everything that you've spent money on in the last five years and then give us your plan for what you want to buy or replace over the next ten years. From that information, we can identify opportunities for every dollar that you will invest for new, green energy savings.

For virtually every capital repair, we can find a green component within it that can be re-directed for new energy savings without spending any additional capital dollars.

That would be our claim and that is what we consider for cost-effective green retro-fitting of an existing building.

BY STEVEN B. KRATCHMAN, AIA 

KRATCHMAN ARCHITECTS