Unless someone strenuously objects, I‘d like to start an argument. When it comes to sustainability and the “green” theme, condominiums and HOAs don’t get no respect.  

 The primary focus of the U.S. Green Building Council and its Leadership in  Energy and Environmental Design (LEED) program is on the design of new  construction. Propose a tower in Dubai with a couple of solar panels and the  project goes viral. Implied is the proposition that LEED certification brings  with it recognition of reduced future operating costs, which translates to  higher market value at resale.  

 Yes, it’s certainly true that it’s easier to introduce new technology at the conceptual design stage than trying  to fit it into existing construction. Still, it seems to me that the LEED  program is noticeably less inspirational when it addresses existing  multi-housing. Few of us will become uncontrollably motivated in trying to save  the planet and operating costs through more efficient cleaning products and low  VOC paints. And yet, a case might be made that perhaps those of us in the  industry share some responsibility for this. Perhaps if we shared more of what  we discovered works (and does not work) in controlling capital and operating  costs we might get some long deserved recognition.  

 Consider Multi-Housing Initiatives

 After all, where else but in existing construction could the feasibility of  now-accepted sustainable techniques and products be tested?  

 Take, for example, harvesting rainwater to conserve potable water and reduce  costs. We recently worked with a client association that was spending what  seemed like an exorbitant amount of money to water lawns and shrubs. In the  arid to semi-arid western U.S., where water is a precious commodity, rainwater  is collected and used for non-potable purposes such as crop and lawn  irrigation.  

 Might those techniques be used by condominium associations in the Northeast?  Here is what our investigation uncovered.  

 Rainwater harvesting, preferably done by collection of roof runoff, takes place  in four steps: collection, storage, treatment and distribution. The roof runoff  needs to be treated to remove the “first flush” of debris that has been sitting on the roof since the last rain event. The  filtered water is collected in a buried cistern, usually of pre-cast concrete,  the size of which is a function of the area of contributing roofs and the  frequency/quantity of rainfall. Rainwater harvesting designers try to size the  cistern (which is the major cost item) for about four weeks’ worth of irrigation, which in New England ranges from about three to four  inches of rainfall. A pump within the cistern pressurizes the irrigation  network/ sprinkler heads with the harvested rainwater. Another source,  typically purchased drinking water, must be available when there is no stored  water available. A backflow preventer defeats crossover of rainwater into the  potable water supply.  

 Return on Investment

 Clearly, there is a fairly significant amount of equipment making up the initial  capital investment. And, of course, that equipment will require future  maintenance; filters and the cistern itself require periodic cleaning. Initial  costs for a rainwater harvesting system range from $0.50 to $1.10 per gallon of  cistern storage (installed) depending on site topography, building spacing, and  the logistics of the existing irrigation system. Key, of course, in the  calculation for the return on investment is the cost of the purchased water the  rainwater is replacing.  

 Our client association’s buildings were fairly well spread out which meant that for a central system,  all the individual roof contributions would need to be piped to a common header  feeding one large cistern. Add in the cost for the connections to the municipal  water system, and the return on investment could not be justified. The client  chose instead to reactivate two wells to feed the irrigation system—a common solution.  

 But what about individual rainwater harvesting for clusters of three or four  buildings? The roof downspouts of another client association all discharged to their  individual drainage fields. Could their outfall be diverted to cluster systems  of three or four buildings? Here the cost of the multiple cisterns was  acceptable but the logistics of supplying each system with backup municipal  water shifted the ROI to marginal for their particular financial position.  Bottom line: rainwater harvesting for landscape irrigation is heavily  site-specific, responding to each set of unique conditions. But in our research  we learned something that everyone can use. Having an audit performed of your  irrigation system could save you significant operating costs if you are buying  water from a municipal or private source. It should be done by a certified  auditor who will review the design, analyze the water demand for your specific  landscape and test each zone to make sure the right amount of water goes where  it should for as long as it should. The fee is well worth the investment.  

 Capital replacements are routine with condominium associations. But they don’t need to be replaced-in-kind; they can be opportunities for introducing  sustainability.  

 Case in point: The replacement of a roof over one client association’s indoor swimming pool. The new roof structure is now well-insulated and its  white plastic membrane cover reflects the solar radiation. The result will be  reduced winter heating and summer cooling costs. And with easier control over  the ambient humidity levels, the masonry walls should not sweat to the extent  they once did. We will be checking future operating conditions and energy  costs. Surely, there are some LEED points just waiting to be awarded here.  

 The takeaway is that management of existing condominium and HOA associations  have long been in a sustainability and “green” mode as they look to get the best return they can for the membership’s buck. Need we be reminded that the need is greater in these lean economic  times? Perhaps expanded sharing of our individual efforts will help in that  regard.  

 Robert J. Burns, PE, RS, is the principal of Burns Associates-Engineers of  Portsmouth, New Hampshire.