It’s probably because we’re flatlanders. Prairie dwellers bored with even the level best in Midwest landscapes, we find every dip, slip, slope or hillock beguiling by degree: The steeper the grade, the sharper the attraction.
So it’s no wonder the Chicago area’s most sought-after and expensive home sites overlook lake bluffs or ravines that promise edgy thrills and beautiful views.
“The views toward the lake and in the ravines are wonderful. Especially at this time of year,” said Ernest (Tony) Grunsfeld, of Evanston-based Grunsfeld Shafer Architects LLC, who has built 30-plus high-end homes near bluffs and ravines and lives in one himself.
“It’s like being in fairyland with such prolific wildlife, birds and trees,” he said.
But lofty sites come with unique challenges: “Whatever you do requires constant maintenance,” said Grunsfeld.
Bluffs and ravines are constantly shifting, and are strongly impacted by water which gradually nibbles away tableland, says Tony Kiefer, a geotechnical engineer with STS Consultants Ltd. of Vernon Hills.
A home’s foundation often must be very deep. Additions are difficult. Landscaping is both necessary and tricky.
Slopes need to be watched for signs of erosion. And homes on bluffs and ravines are exposed to greater danger in severe weather conditions.
Terri Weinstein vividly remembers the storm that transformed the ravine behind her 1952-built Usonian-style Highland Park home into a nightmare of wind-whipped trees “bending like pipecleaners.”
While the house itself stayed secure, falling tree limbs knocked the deck off. Weinstein has since replaced it. But other ravine-specific challenges continue.
Landscaping, for example, necessary to slow erosion of the slope, is an evolving process.
“The canopy of leaves above makes it difficult for plantings to take,” she said, describing a system of trial and error.
The 3,000 plants Weinstein put in on one side of the ravine languished, for example, but then reseeded themselves on the other side.
Structurally, building on or near steep slopes requires the extra expertise of soil engineers.
“You should not build on a bluff unless you’re prepared to do it with an engineer,” said Grunsfeld.
The experts bore into bluffs or ravines to take soil samples, which are analyzed to determine the strength of the soil and how stable a slope/bluff/ravine actually is.
“We’re also looking to answer three questions,” said Kiefer. “First, what’s protecting the tow [bottom] of the slope from water erosion?”
With lake bluffs, there should be some type of wave protection — gabions, breakwaters, etc., he says.
“Second, how steep is the slope?” [A ratio of two horizontal to one vertical is usually considered stable.)
“And how well vegetated is the slope?” [A nice mix of native trees, shrubs and forbs is a big plus.]
Without such studies, “People may try to do all sorts of crazy things,” said Grunsfeld.
He recalls one homeowner who put a tennis court halfway down a lake bluff only to have the bluff shift, causing the court to collapse and fall in chunks to the beach below.
“It cost that family more to remove the debris than it did to build the tennis court,” he said.
To avoid such scenarios and protect the health of the slopes, some municipalities limit just how close to the edge of a bluff or ravine homeowners can build.
The seven lakeside Chicago suburbs most known for bluffs and ravines all have different rules. In Glencoe and Winnetka, houses can still be built very near ravines and bluffs.
In Lake Forest, new construction must be about 75 feet from the edge of a bluff; for ravines, it’s 20 feet.
In Highland Park, it’s 40 feet for lake bluffs, 50 for swimming pools and 10 feet for ravines.
But even communities with stringent rules have grandfather clauses that allow owners of older homes to upgrade and expand houses as long as they build on the original footprint.
That means most of the five to 10 sites Kiefer evaluates each year are those where people are trying add more space, building extra levels or decks.
Where it’s allowed, “homeowners almost always want to be closer to the edge,” said Kiefer.
Ensuring that foundations will support homes and additions, engineers such as Kiefer and Daniel Creaney, president of Northbrook-based Daniel Creaney Co., a civil engineering firm, may require very deep pier-type foundations that may go 20 to 30 feet below the surface. They also sometimes recommend using retaining walls and ravine-repair measures such as gabions at slope bottoms.
Chicago architect Paul Berger used deep footings, concrete and steel to shore up Barbara and Rex Sessions’ ravine-side home in Sawyer, Mich., which was recently rehabbed to make it usable year-round. They also reinforced the concrete retaining wall next to the garage before converting that to a coach house.
Barbara Sessions says she loved the charm of the house, which was built in the 1920s and used as a summer home by the original owner. But there was no sense of scale, no main entrance and no insulation.
Delving into the structure, Sessions discovered “it was like a house of cards,” which had settled and sagged toward the ravine.
Berger and contractor Craig Moore completely gutted the interior of the home, saving three massive stone fireplaces and much of the old-growth interior wood paneling for reuse in the rehab.
Opening up the space, Berger removed “all these tiny, chopped-up rooms,” placing an open kitchen at the center. They also raised the roof above the kitchen, and installed a new main entrance surrounded by clerestory windows.
Paying attention to the sides of a slope is critical, says Creaney:
“It’s really important not to let water run over the edge and down the slope, which causes slough-off and erosion. Instead, you should install drainage systems that take the water either to the front of the property, or to the very bottom of the ravine.”
In addition, careful landscaping can restore and maintain the slope and reduce erosion.
Too many trees — especially invasive species — leads to erosion-prone bare soil on the sides of the slope.
To let light get to the slope, allowing growth of shrubs and grasses, Larry King, city forester for Highland Park recommends cutting invasive species such as Norway maples and buckthorns down to low stumps, then poisoning them.
“You leave the roots intact, and then plant a new combination of grasses, shrubs, forbs [broad-leaved herbaceous plants], and wildflowers, blending in some intermediate trees with what is there,” King said.
Clem Hamilton, director of research at Morton Arboretum and a specialist in steep slope landscaping, agreed.
“The reason you want a variety of plants for slope stability is because they all have different root structures and levels.”
