Commercial Calculations

Though they seem rough and dangerous, commercial construction sites are actually quite delicate, requiring precise coordination between steelworkers, masons, electricians and dozens of other contractors in order to erect safe and solid buildings.

On a construction site’s surrounding grounds, irrigation contractors have equally important jobs in establishing the lines that will sustain the new building’s landscape. Indeed, before even beginning to work on a site, irrigation contractors must go through their own detailed and elaborate processes to develop accurate designs and proposals for what the new installation will include.

"Creating a proposal for a large commercial site without an existing irrigation plan is time consuming," says Roy Tveite, designer/estimator, Treasure Coast Irrigation, Hobe Sound, Fla. "There are a lot of factors to consider that will change our final design or bid." Tveite goes through several steps when developing a commercial irrigation installation proposal, but meeting with a project’s general contractor and having a thorough knowledge of Treasure Coast’s operating numbers helps him create solid, profitable installation projects.

PROJECT SPECS. Because 97 percent of Treasure Coast’s commercial projects are new installations, Tveite has learned from experience that meeting with general contractors on a construction site will help him identify the right specifications to use in his proposal.

"If the project we’re bidding on doesn’t already have an irrigation design, normally I would approach the general contractor or the property owner and find out what kind of system they would like," Tveite says. "For example, if it is multiple-family project that has a lot of common area, does he wants each house to have an individual irrigation controller or does he want part of the property on central control? There are broad questions like that and also more specific questions about what kind of spray heads they want to use – do they prefer 12-inch pop-ups in a shrub bed or a smaller size?"

Additionally, Tveite visits the construction site to get an idea of the size and grade of the project, as well as knowledge of the type of water source and any reclaimed-water issues that may require permits or special materials. Ultimately, however, many product decisions are dictated by the project’s budget. "Quite often, property managers will want to keep their costs down, so there may be more sophisticated materials that we would like to use, but there may not be an allowance for it in the budget," Tveite says.

For example, because landscape irrigation in south Florida frequently comes from reclaimed water, Tveite often shares with general contractors the idea of using valves with scrubbers in them that will eliminate some of the extra debris in the water. "There are no requirements to use these particular valves, and we know it will run up the price of our bid, so there’s a question of whether we should put these in and deal with it later or not put them in at all," he says. "In those situations, we will usually include the more sophisticated products and allow the customer to change that if they want to. Sometimes the money isn’t in the budget or, on a renovation, they may want us to stay consistent with the products that are already on the site. Our goal is to be up front with the general contractor and the property owner and explain to them what we think will be best for them and for the system in the long run."

DESIGN & LABOR. With an understanding of the basic specifications, Tveite creates a mock-up of the irrigation system using computer-aided design (CAD). This helps him develop an approximate bid that he can perfect later. "I design something for myself with CAD that will give me a guideline of the project cost," Tveite says. "It’s a very quick format that helps me determine how many spray heads we’ll need, how much pipe and so on. He adds that if Treasure Coast is also designing the irrigation system as opposed to bidding on another company’s design, the design cost is usually 10 to 15 percent fo the total cost of the system.

Tveite uses historic information to estimate the cost of each design element and once he has a good idea of how extensive the installation will be, he applies labor rates to the price of the bid. "On average, a commercial site with a wide-open area will be about 10 to 12 cents per square foot for labor," he comments. "Tighter areas like parking islands often come in a little higher – about 15 to 17 cents – because it may require more hand digging or other detailed work. Every plan is unique and has their own labor rates, but we find that these guidelines work well if we are just asked for a rough estimate or if we have a proposal that needs to be turned around very quickly."

Of course, irrigation contractors have to include more than just labor and materials in order to make money on these jobs. Tveite says Treasure Coast tries to include 10 percent profit in their bids, as well, but that can often be a high expectation. "A 10-percent margin would always be nice to have on commercial irrigation, but what you actually get is often market-driven," he explains. "On a job that’s several acres, 10 percent could be a lot of money and if there are a lot of people bidding, you may have to reduce your margins to stay competitive. A lot of times, commercial projects will only give you 6 or 8 percent profit, so you have to increase your efficiencies on the job to make up for that."

Treasure Coast has several efficiency-boosting practices in place depending on the type of project its crews are working on. For instance, they find that properly staging materials on large jobs helps work move smoothly. "For a job that’s on an acre or more of open space and with good working conditions, before we get started we lay out which direction we’ll be working in," Tveite says. "If we can start working in an area where we can run several hundred feet of mainline without being interrupted, we make sure we have all the materials we’ll need to complete that section on site."

During the bidding process and throughout the course of a project, Tveite also takes note of how many day laborers or foremen will need to be on site at a given time. This is especially important in tighter areas that might require a lot of hand-digging. "On commercial sites, day laborers are usually necessary and we’ll determine what machinery will be most proficient for them to use and we’ll keep those machines on the site," he explains. "But we have to watch how many laborers we have doing hand digging rather than using a trencher or another machine because the labor costs for hand-digging are much higher."

Tveite says that while the company bids the cost of using a walk-behind trencher at the rental rate of about $65 to $75 per day, hand-digging can cost as much as $12 to $18 per hour, per worker. Keeping costs like these in line helps the company retain their profit margins on commercial work.

The author is associate editor of Lawn & Landscape magazine and can be reached at lspiers@lawnandlandscape.com.