Laurel builder Michael T. Rose helped write the book on saving trees.

For 30 years, he and his development company have been winning awards for combining construction and conservation. For instance, at Solomons Landing, a Calvert County waterfront community whose final phase is under construction, Rose got permission from local regulators to put condo buildings on pilings instead of on slab foundations to reduce grading and clearing. And he clustered the buildings to free up more land for trees. The site had been logged two years before he bought it, so he even brought in hundreds of new trees.

"Conserving trees is not an easy task, but in our experience it's worth doing," Rose wrote a few years ago in the preface to a book aimed at builders.

Rose is not unique among home builders; others also attempt to preserve trees. But throughout the Washington area, where construction of not only new communities but also in-fill projects in existing neighborhoods continues at a swift pace, residents regularly mourn the loss of familiar deep woods or just the clump of pines that had buffered them from neighbors.

Trees are pretty. They produce shade. They shelter wildlife. So why do so many builders cut them down?

It is easy to jump to the conclusion that they do so only because it is faster and cheaper to build that way. Those are considerations. For a tree-conscious builder, "it's very hard to compete against a guy who isn't going to treat the land the same way," said Gary Moll, vice president of American Forests, a Washington-based nonprofit that is one of the nation's key tree preservation groups. Being innovative in planning and designing to save trees takes time and money, he said.

But builders say those are not the only reasons. Laws and regulations meant to achieve other goals can get in the way of saving trees. The structure of the construction industry, where the company that prepares the land and the company that builds the house are often different, can also be an obstacle, they say.

For almost as long as humans have built houses, they have cut down trees to do so -- you cannot build a log cabin without logs. But rapid development has brought rapid loss of trees.

Based on comparison of satellite photos over the years, American Forests estimates that the average tree cover in the Washington-Baltimore corridor declined to 37 percent of the land in 1997 from 51 percent in 1973. During those years, the region lost 114,222 acres of heavily forested land -- acreage with more than 50 percent tree cover -- a decrease of 20 percent.

Conservationists say the rise of production home building in the 1950s quickened the decline in the nation's trees. Builders were focused on mass-producing housing at prices many people could afford. That encouraged simple layouts and large tract developments.

While production building did get houses up quickly and cheaply, building in large tracts promoted the wholesale clearing and leveling of sites. That led to storm water drainage problems, erosion and flooding, according to conservationists.

In the past decade or so, builders and localities have been pushed to change their approach, Moll said. Tree ordinances have been adopted around the country. Some only protect public or "street" trees, but others are meant to preserve trees during construction, or to mandate replacements if trees are removed. Maryland, though, remains alone in having a statewide law requiring towns and counties to establish systems to protect trees during construction.

"One of the great misconceptions is that builders uniformly want" to eliminate trees, Rose said. Often, he said, builders are pushed into such decisions by long-standing zoning rules, planning ordinances and utility demands.

"Builders do not subscribe to the scorched-earth approach," he said. Instead, "they like to follow the rules and get things accomplished as fast as possible" and as cheaply as possible, he said.

But following the rules often leads to tree removal because zoning or subdivision regulations do not take tree preservation into account, he said. Road widths, for example, have been set to allow a certain number of cars and a fire truck to pass, so it is not always easy to get permission to make roads narrower to save trees along the edges. Also, utilities hamper efforts because their goal is to keep their rights of way clear and they resist sharing underground trenches, Rose said.

Moll agrees that government and utilities play a role in urban America's move "from green to gray" over the past 50 years. But builders are not blameless, he said. "They can do more, there's no question."

In Maryland, for example, he laments that builders can choose to pay for trees to be planted off site rather than having to keep or plant more on site. "Unfortunately, what has happened to a great extent in Maryland is that builders can pay fines [for not complying with local regulations mandating a certain amount of tree cover] or can in some cases comply by putting trees in reserve," Moll said. The state's law, he said, is a good start, but not enough.

Steve Seawright, head of Seawright Homes of Bethesda, another builder whose tree-conscious projects have won awards, said that the structure of the residential construction industry is also to blame. Usually, a developer and a builder are two different companies. The developer assembles land, deals with government requirements, prepares roads and utility infrastructure, and divides lots. The builder constructs houses. Seawright does it all in his communities, which he said increases his control.

"The typical pattern that's prevailed over the last 20 years is that there are people who develop and people who build," he said. "And the guy who's developing the land does what he thinks will make the land most inviting to builders without any foreknowledge of what's going to be built on it. So what we've ended up with are generic building sites, where the land has been mass-graded regardless of what the land looked like. [These developers think] you just make it look like a pancake . . . because you don't know who it is that is going to build and what it is that they're going to build."

Steve Clark, an urban forester who works as a consultant to builders, said he believes builders, cities and citizens are working together and "that people now are looking for a common-sense approach on how to develop America."

Each party has to compromise, he said.

"A lot of builders are still working under the [belief] . . . that the trees don't live" if they try to keep them on site, "so they say, 'We don't need them.' They think they can't build and save the trees because that's the way they've always thought and because that's what their grandfather told them."

But, Clark says, building neighborhoods with trees "is economically feasible or I wouldn't be sitting here."

American Forests has been working with the National Association of Home Builders for about 17 years to build a dialogue over trees and to show how it is in the interest of builders, cities and citizens to protect them. Not only do trees reduce pollution, keep buildings cooler and eliminate some of the need for expensive storm water management systems, conservation groups said, but they add warmth and value to a property lot. The National Arbor Day Foundation is another partner in the effort, which includes awards and designations that builders and cities can use in marketing or publicizing their efforts.

According to "Building Greener Neighborhoods," a book co-written five years ago by tree preservationists and builders, including the preface by Rose, trees can add $2,000 to $5,000 to the market value of a property. Others said mature trees can boost the market value of a home by an average of 6 or 7 percent.

Seawright agrees. "Most people prefer to have trees on their property rather than to have little sprigs planted and to have to watch them grow for 20 years," he said.

Seawright said he has always factored trees -- and the topography, or lay of the land -- into his designs because he believes buyers want to preserve the natural settings. "We believe it is the right thing to do," he said, "and we think that the conventional wisdom -- that it's less expensive to wipe them out than to live with them -- is wrong. . . . The financial results are the same, if not better."

Howard County Sierra Club activist Dennis Luck, for one, remains wary. He said he is so busy tracking development in and around Columbia that he cannot calculate whether residents are more upset about one particular project than another. But it looks to him as though trees are coming down all over.

"We always get upset when the trees are taken down, and we've tried to plant trees all over the county, but the drought years just decimated our work," Luck said.

When asked about community concerns over several developments recently going up simultaneously in and around downtown Columbia, Luck said, "People are concerned about tree preservation all over the county." He thinks that what concerns residents most are cases of in-fill building, or development in wooded areas and empty lots between existing developments.

"If the rules permit it, the builders are going to do it. . . . If the law is on the books that allows clearing, then people have to change the law," Luck said.

In some cases, said builders such as Rose and Robert Kaufman, a former associate of Rose's who now works for Augustine Land and Development, residents think the worst of builders because they cannot see that trees are being saved. Or they do not realize the value of removing trees from high-density urban sites to save trees in areas elsewhere that are zoned for lower density. All they see are the earthmovers taking down the trees.

"People get emotional about trees," said Marian Honeczy, the coordinator of Maryland's tree conservation program. But they may not realize that trees have been saved, she said.

"It's not something that you can drive down the street and see," she said. For example, she said, trees might be retained far from roadways around critical areas such as streams. In other cases, she said, a county might want to protect larger blocks of forest off site, and prefer to give up trees in one location to get a bigger stand of trees elsewhere.

Maryland's tree protection law applies to any development on parcels of 40,000 square feet or more, or about an acre or more, and requires that any activity on that land be reviewed by the local government's forest conservation program before construction.

The law also requires a certain amount of tree cover, depending on the zoning. For a medium-density residential development, 25 percent of the land must have tree cover. For a high-density residential project, 20 percent tree cover is required.

All of Maryland's counties and 80 of 91 towns have passed ordinances with tree conservation programs since the Maryland law was approved in 1991, Honeczy said.

The penalty depends on the county, but generally builders who do not comply must pay 30 cents a square foot for the area that was disturbed, and/or $1,000 a day, Honeczy said. Counties can also issue stop-work orders, which "are often more effective, because it costs more money [than a fine] if a builder has to send everyone home," she said.

Virginia has no state law on tree conservation, but individual jurisdictions do. Fairfax County celebrated the 30th anniversary of its urban forestry program last month, said Michael Knapp, the program's director.

The District's urban forest preservation act was passed last year and took effect in April, chief forester Ainsley Caldwell said, but regulations are still being written. The District law requires permits to take down any tree on private land that is greater than 18 inches in diameter or 55 inches in circumference. A resident can opt to plant replacement trees or to pay into the District's public tree fund the equivalent of $35 per circumference inch of each tree that is not replanted.

An aerial view of Solomons Landing in Calvert County, where builder Michael Rose used construction techniques that saved trees while he planted new ones.At the Solomons Landing development in Calvert County, seen here from the community dock, the builder reduced clearing to preserve trees.