Most homebuyers base what they are going to be spending every month for their new digs on how much they are borrowing and the interest rate they're paying. But if that's all they consider, they are missing a big component of their monthly housing costs -- their utilities.

What's more, the cost of gas, oil and/or electricity to heat and cool the house is only one part of potential utility bills. Unless you will be using a well for your water and a septic tank for your sewer, you'll have to pay for those conveniences every month, too. And then there's trash removal and possibly even homeowner association fees.

The total cost for these necessities could add as much as 25 percent of your mortgage payment to your total monthly housing costs. Depending on the size of the place and how often you run your dishwasher and dryer, the outlay for utilities could run as much as $500 a month. Maybe even more.

Fortunately, if you are purchasing an existing house, it won't be terribly difficult to estimate your utility bills. At least, not if you have a cooperative seller.

Ask the seller for a list of what he or she paid for the various segments of utilities for the last 12 months. It may be a chore to compile, but bills just for the last month or two won't be terribly meaningful.

Of course, your monthly bills might be different from the seller's. You might be setting your thermostat higher or lower, depending on your comfort level, for example.

You might use more or less water, depending on the number of people in your household and how hot they like their showers and baths. And your kids might be running in and out all day long, which will run up your heating and cooling bills. But at least you'll have a decent approximation of what your costs will be.

Another way to estimate your costs is to use one or two or maybe even three of the various online utility estimators. They aren't pinpoint accurate, and as noted above, how you use the place will have a great deal to do with your monthly outlays. But again, they will give you an idea of what you'll have to spend in addition to your mortgage payment.

Myutilityscore.com is one of the newer sites. Simply plug in your new address, and it will divine your monthly, yearly and peak costs for electricity, gas and water. The site also will estimate your total annual bill and give you an overall score of one to 100, with 100 being the lowest costs.

It also will allow you to refine your estimates by adjusting for the number of people who occupy the house, your intended thermostat settings for winter and summer, and whether or not the place will be occupied during the day.

CPSEnergy.com has separate calculators for appliances, ghost-energy (plugged-in appliances use energy, even when they are turned off), heat pumps, televisions and lighting, plus an overall home energy calculator. These appear to be somewhat more cumbersome to use, but they still do the trick. (San Antonio-based CPSEnergy is the country's largest municipally owned energy utility.)

General Electric has a detailed electric cost calculator that also includes lighting and personal appliances, and a Home Energy Saver (energy.gov/energysaver/energy-saver) estimator from Uncle Sam that allows you to estimate your annual costs plus the cost to operate specific products.

In addition, look for the EnergyGuide label, the yellow tag you'll find attached to most appliances. It tells how much energy an appliance uses. Add the figures up and you'll have something approximating what you will be spending every month.

As you can see, trying to determine what your costs will be for a brand-new house is somewhat more problematic, if only because the place has never been occupied. But savvy builders will have asked the local utilities to provide estimates of what it will cost to run the house.

If your builder hasn't already done so, you can call each provider and ask for an estimate. Not all gas and electric companies do this for individuals, but it is worth a try, nonetheless. (With some, it's a mixed bag.)

Assuming all the major electrical equipment is installed, Potomac Electric Power Co. (PEPCO) in the Washington, D.C. area will "come out and give a customer an energy bill estimate," a spokesman said.

For people buying existing homes in suburban Maryland, PEPCO will send them the previous 12 months' worth of utility bills on the property so they can gauge their energy costs. And if you are an existing customer moving to a new total-electric house, you can enter your account number to use PEPCO's online energy cost calculator.

Finally, if you are willing to spend a little cash -- and your builder is willing to do so -- hire an energy-auditing firm to estimate how much your utility bills should run. Savvy builders will have done so for each of their models. But if yours hasn't, pay a certified auditor using a generally accepted index such as HERS, which stands for Home Energy Rating System, to give you an idea of your monthly outlay.

Would-be buyers of "green" homes may not be speaking the same language as the builders who are putting them up.

The verbal disconnect between builders and buyers is evident in a 2015 study of consumer preferences by the National Association of Home Builders, which focused exclusively on green features in homes and communities.

The primary objective of the study was to ascertain consumers' level of awareness of various Earth-friendly home features. But what was more striking was that buyers and builders are not always on the same page when it comes to terminology. In other words, perception and reality are not always the same.

For example, a builder might describe his offerings as "green," which has become the go-to euphemism to describe a house that's more environmentally friendly than the everyday, run-of-the-mill new house. According to the study, though, people tend to believe they receive more value from one that's described as "eco-friendly."

Both terms mean roughly the same thing, but 68 percent of the 3,370 consumers who bought a home in the last three years, or are planning to do so within the next three years, said they feel the most value comes from an eco-friendly home, compared to the 32 percent who said a green home offered more value.

This wordplay problem continues throughout a number of terms builders use to describe their sustainable products. Take the words "comfortable" and "livable." If the builder advertised a house as livable, according to the study, he might miss the mark with 83 percent of potential customers, who find more value in a property that's said to be comfortable.

Similarly, "low-flow," a term used to describe fixtures that use less water, means little to consumers, only clicking with 18 percent of them. But the same fixtures described as "water-saving" tend to resonate with 82 percent of consumers. Ditto for the term "environmentally friendly" versus "green-conscious" -- 81 percent to 19 percent, respectively.

The same disconnect can be found throughout the 26 pairs of words or phrases builders might use in promoting their "high-efficiency" homes. Even that term isn't immune: Respondents believe there is more value in an "energy-efficient" house than in a "high-efficiency" one.

Some of the other popular terms thrown around by builders that may not be universally embraced by buyers include "low-impact," "reduced energy use" and "nontoxic materials." Buyers, on the other hand, said terms such as "environmentally conscious," "lower utility bills" and "healthy living environment" have more of a ring to them.

There were only four pairs of green concepts for which opinions are close to evenly divided: "health" vs. "comfort," "resource-efficient" vs. "zero-waste," "disaster-resistant" vs. "resilient" and "net-zero energy" vs. "carbon neutral."

Despite the marked differences in semantics, the study found that energy efficiency is now paramount to consumers, who rank that attribute as the second most important to them. Only safe communities ranked higher.

"More than 50 percent of respondents in every age group, income bracket, household type, race, ethnicity, gender, census division and home price point ... agree that being energy-efficient is the most important attribute when facing a home purchase or remodel decision," the study found.

The builder's reputation, proximity to shopping and amenities, proximity to work, preferred school district -- all advertising hooks often used to lure buyers to various subdivisions -- are all further down the list of features that buyers said would influence their purchase decisions.

The study's results don't surprise Suzanne Shelton of the Shelton Group, a marketing and communications firm focused exclusively on energy and the environment. She says builders and product makers often use technical language that doesn't mean much to consumers, who mostly want to understand the benefits of a given feature -- not the building specs.

"The industry throws around a lot of words consumers don't understand," Shelton says. For example, the term "net-zero" means the house uses no energy -- a good thing, surely. But the term "sounds negative, and registers negative" with homebuyers, she says.

Her company's own study of energy-related buzz words found that the terms "green," "eco-friendly" and "sustainable" registered as "expensive" with about 3 out of 4 consumers. Negative-sounding terms such as "net-zero" were even less popular.

Many a sale has been killed by an independent home inspector's report.

But these days, an inspection is such a common requirement that there's just no way around it. So the best thing sellers can do is prepare for a top-to-bottom property examination -- and help their home obtain as clean a bill of health as possible.

For starters, it's wise to hire your own inspector to give your house a once-over prior to putting the place on the market. That way, you can identify any problems that could become bones of contention with your buyer, and repair them ahead of time.

After that, savvy sellers will prepare their properties for the inevitable inspection by performing all those maintenance tasks they've been putting off -- fixing those items they know full well are not working properly, but have been ignoring. This also generally makes it easier for the examiner to do his job.

Inspectors are not supposed to be lulled into complacence by a clean and well-maintained house. But some professionals in the field confide that just as an organized house makes a better impression on would-be buyers, so, too, does appearance have an impact on inspectors.

"A well-maintained home does not necessarily cause the inspector to 'go lightly'," a president of the American Society of Home Inspectors once told me, "but most will look with more vigor at houses that are not so well maintained."

Not all inspectors agree. Some say that a good professional will give every house the same thorough examination, no matter what shape the house appears to be in. They say a clean, organized house will make it easier for them to do their jobs, but it won't change how they do their jobs.

Either way, it's a good idea to clear the property from all debris and obstacles so the inspector can move around easily. Remember, he or she is going to want to walk all the way around the exterior.

Many examiners will provide sellers with a pre-inspection checklist so they can be sure the house is ready. These lists contain a slew of things you can do, from repairing cracked concrete sidewalks to fixing loose deck railings.

Inside, provide clear access to the attic and the crawl space. Often, these entrances are found in closets, so be sure to move out whatever clothes, shelves or shoes necessary to allow the inspector to do his thing.

If you have a basement, clear a path around the perimeter so the inspector can check out all the walls. Ditto for a path around the furnace, air conditioner and water heater, wherever they may be located in your house. While you're at it, replace the furnace and A/C filters.

In addition, make sure all electrical outlets and switches are in good working order. If you are not getting power from an outlet, have it fixed. If a lightbulb is burned out, change it.

Take care of those little things you've learned to live with -- a drippy faucet, for example, or a small hole in the wall that one of your little darlings put there with an errant toy. Typically, these are easy to fix. But if ignored, both the inspector and the buyer will wonder what else you've disregarded.

Proper maintenance reduces the number of flaws an inspector is likely to find, which in turn reduces the impact of his or her report to the buyer. "Lots of comments" on an inspection report -- even minor comments -- equals "bad house" in many buyers' minds. But a short list will lessen your exposure to nitpicking, nickle-and-diming and low-balling.

At the same time, some examiners don't like to see too much evidence of fresh repairs. A slew of fixes and recently performed maintenance tasks suggests that the house has been poorly maintained over the long haul, one inspector told me. A typical inspection takes about three hours, during which time more than 1,600 items, inside and out, are evaluated. But the examiner can't see behind walls or under roof shingles, so recent repairs may set the inspectors' antennae to wiggling.

For example, he's obligated to report that small hairline cracks in the foundation have recently been caulked and painted over. That could be insignificant. But since the degree of risk is unknown, it could be an indication that more expensive repairs are warranted. And that could turn your buyer off.

It's never a good idea to conceal defects, major or not. Not only is it illegal in most states, it is difficult to fool the expert eye of a trained inspector. Attempting to hide house problems is just about as effective as brushing and flossing for the first time in months just before going to the dentist. Inspectors are just too good at spotting clues.

If you are not adept at significant or complicated repairs, hire a reputable contractor. It's well worth the money, inspectors maintain. It's too easy to spot amateurish, sub-par work. And by using a professional, you can provide paid receipts and warranties to prove the work has been done properly.