Feeds:
Posts
Comments

Posts Tagged ‘spatial design’

In my work doing residential landscape architecture, I have encountered a number of instances where someone has bought a house on a sloping piece of land, getting what seems to be a steal. Usually, the buyer/client first tackles work on the house, revising its interior, and sometimes its exterior, to make it just as he/she wants it to be. House modifications can take years. When the house update is done, the homeowner turns his/her attention to the landscape. Most people want as much usable outdoor space as possible: a patio is a pleasant place to sit, a big, level lawn lets kids play comfortably and within sight, and walking, driving, swimming, or playing sports are all easier on flat surfaces. And it’s when the owner of a sloping site wants to enlarge their usable domain that it becomes clear why the dream house was such a bargain.

Why? Because slopes are expensive to unslope.

For people to use the land immediately around their house with any degree of comfort, it’s necessary to make level areas. A patio typically has a cross-pitch or slope of not more than 2% (just enough to drain water), and a lawn that slopes no more than 5 or 6 percent is best for active kids to organize and play games on. When a house is built on really noticeably sloping ground, the grade can measure anywhere from 8 to 15 percent, or more.

Sometimes earthen banks can hold up a level area; sometimes strategically placed boulders can do the job; often large retaining walls are necessary. Where surface area is scant, retaining walls may be the most efficient way to hold land level. Walls tend to be costly.

To start from a different point: A couple of years ago, I had the good fortune to visit a friend in Konstanz, Germany. While there, we took a number of side trips into Switzerland. We punctuated our train trip to Appenzell, Switzerland (home of many cows and of Appenzeller cheese, a famously stinky but delicious local specialty) with a visit to St. Gallen, home of a UNESCO World Heritage site, the Library of the Abbey of St. Gall.

St. Gallen, Switzerland, from the air. The medieval walled city core is clearly visible among the more regular fabric of later-built streets and buildings. The Abbey and its World Heritage Site Bibliothek can be seen at about four o'clock in the walled part of the city.

The Bibliotek (Library) was closed when we arrived. We were ready to take a rest anyway, so found a spot on the spacious and sunny courtyard lawn and got out a picnic lunch. The day was bright and only slightly cool; though cars puttered by outside the court and a bell nearby clanged the hour and several other people sat on the grass and on nearby benches, the courtyard felt extraordinarily tranquil and pleasant. We munched and chatted, and I tried to put my finger on what made the courtyard feel so different from the surrounding area.

Look closer at the Abbey and its grounds. It takes up a large area within the walled city, and though the surrounding land slopes to the northwest, (that is, toward the photo's top left corner), the huge Abbey courtyard is almost perfectly level.

I had been thinking about the slope/cost issue for a quite some time, and it sprang to mind again in that peaceful abbey close. From the railroad station in the valley bottom, we had climbed winding medieval city streets to get to the Abbey; the walled city around the Abbey sat considerably higher than the station itself. Outside the three-sided Abbey complex, streets bent and sloped against the thick walls of the Roman Catholic enclave. Inside, green grass carpeted an utterly level quadrangle, muffling sound and lying like a tablecloth on a tabletop

Outside the Abbey walls is an orderly but dense fabric of masonry buildings and narrow streets that wind up and down the hilly terrain. Inside the Abbey walls, the utterly level and open ground of this tranquil courtyard puts on display the power and wealth of the Church that built it. Photo by kind courtesy of Galen Frysinger, at http://www.galenfrysinger.com/

In this Swiss city, slope is a fact of life. Buildings themselves do double duty as retaining walls; the back door of a house here can easily be situated a full floor above the front door. The city fabric is tightly woven, to conserve energy and again, because amending long sloping frontages can be expensive. Most homes are built cheek by jowl, with little or no space between houses.

The Church was and is a wealthy and powerful homeowner/landowner, as evidenced by its leveling of a sizable piece of the town’s steep foothill to make a vast piece usable ground. The fact that the courtyard lies in the middle of this densely woven city, and that it is given over to luxurious lawn sends a quiet but clear message of power and wealth. While the elegant and extremely solid buildings convey that message, the carving out of level outdoor space speaks just as definitively about the ability of this particular institution to make unlevelled places plain.

Advertisements

Read Full Post »

The other day I was on Beacon Hill and spotted this mostly dead hemlock tree, completely swathed in Boston ivy:

Though this hemlock tree on Beacon Hill is dead, its stripped-down structure maintains usefulness, as Boston ivy covers it entirely with foliage.

Perhaps the owners were simply neglecting their courtyard garden, but I like to think that they saw the mature tree’s size as an asset to the place, and decided to use the deadwood as an armature for another plant, and to use the resulting ‘hybrid’ as a garden element.

I have seen this strategy used with other trees; an ancient, mostly dead apple through which a vigorous rose climbs and blooms, tiny dead crabapple that hosts a clematis vine, and a couple of thriving Norway maples through whose canopies wind equally thriving wisteria vines.

We see bittersweet and poison ivy taking advantage of the height and sun exposure offered by trees; why not use that principle and foster the growth of ornamental vines over dead trees, or, as in the case of the Norway maples and wisteria, let one aggressive species provide a platform for another aggressive species?

Read Full Post »

Don’t you love this photo? Toby Wolf took it at the Crane Reservation in Ipswich, a property of The Trustees of Reservations. He said that for him it has the quality of an oil painting; I agree completely. It has that same dark/light/dark sequence, that same frame/focal point/background flavor as a painting by an Italian Renaissance painter.

At the Crane Reservation, Toby writes, “It looks like The Trustees have deliberately maintained the opening to the view, and that the late-afternoon light, raking across the marshes and the bark of the trees, is what makes it work. I like the light on the ground-layer plants.”

The whole ravishing photo.

Here’s an example of landscape management supporting a design intention. Sometimes we design places with stone, wood, earth, metal, and plants; sometimes we design views, and tweak a visitor’s perception of a place by what we leave in, what we remove, and how we frame and focus what they see. Obviously, a photograph can be manipulated to do these things, but sometimes a photograph simply records a perception that has been shaped by others, as The Trustees have apparently shaped the Crane Reservation view.

A view framed by dark elements, a view into a light space, a view toward water, a view toward curves — what a pleasing combination. I want to take a bite out of this photo.

Read Full Post »

The massive four-stem Norway maple that blew down in high winds last week.

Following up on the list post item from June 9, about what to use to replace a lost Norway maple: it will be a honey locust (Gleditsia triacanthos inermis ‘Shademaster’), placed slightly upslope from the Norway stump.

Last week I visited the North Shore seaside site (where last year we revamped the drive court planting and added bamboo and holly for property line screening; to read about those projects, see Refinement and Air Spade In Action) and saw the spatial effect of losing this tree.

Surprisingly, the loss wasn’t as bad as I had thought it would be. The tree’s canopy had taken up a huge amount of space and cast deep shade over quite an area. It had screened my clients from an unappealing view of the corner of their neighbor’s house — but also from a wider view of the Boston skyline in the distance. Now the horizon is wider; they’re going to have a spectacular view of the city’s July 4 fireworks. While the neighbor’s house is unfortunately visible for the moment, the honey locust will mitigate that view. A younger specimen maple just over the property line, which had been hidden by the larger tree, looks healthy, and helps provide a perspective-focusing foreground to the far horizon.

Fortunately too, while the tree provided shade over a wide area of the site, much of its underplanting consisted of junipers and taxus, which should benefit from having more sunlight. The redtwig dogwood, azaleas, and hydrangea will think a bit about how much they like being exposed, but I think they’ll adapt. Even the little spring shade garden should fare all right, protected as much of it by a dense shrub planting from full sun exposure. Many of the herbaceous plants in it are ephemeral anyway, showing up in early spring before any trees leaf out, and fading back as foliage emerges above them.

Shade cast by the now-gone Norway maple protected the little spring garden and its ligularia circle at the path's end.

Our biggest concern for this newly sunny area is the ligularia bed. This bed, banded with a circle of bluestone, makes the southern terminus of a sightline through the tiny spring garden. The ‘Britt Marie Crawford’ ligularia, with its chocolate-brown foliage and golden spikes of flowers, makes a ravishing dot at the bottom of the exclamation point. And it’s a shade lover.

Ligularia 'Britt Marie Crawford' in its circle bed.

It may not be at all happy to be getting sun all day every day. My hope is that it can handle it well enough for long enough to feel relief from the kinder, more dappled shade that the new honey locust will eventually cast.

This site has seen several mature trees come down since last year; neighbors next to the drive court removed a large maple and a lovely S-shaped pine, an ailing ash tree got taken out, and a graceful Russian olive specimen, some 20 feet tall, blew down in the same storm that took the big Norway maple.

Each subtraction has shifted the sun/shade proportions, and each will affect the growth and health of the surrounding area. This kind of change requires adaptation both by the plants and by the owners, and provides opportunities for new ways of seeing a familiar place.

Read Full Post »

What do we see if we look at one place through a particular lens? Last week I was out at Naumkeag in Stockbridge, MA, and found myself appreciating the wide vocabulary of ways that Fletcher Steele used to get garden guests up and down the slopes. Here’s a partial list:

Brick and brownstone steps from the upper lawn terrace down onto the walkway above the peony terraces.  It's unlikely you'd see anything this idiosyncratic (narrow, curves with almost no tangents on the treads, funky riser/tread ratios) built today.

Brick and brownstone steps from the upper lawn terrace down onto the walkway above the peony terraces. It's unlikely you'd see anything this idiosyncratic (narrow, curves with almost no tangents on the treads, funky riser/tread ratios) built today.


Two steps down a grass ramp to a grass landing.  How do you navigate your wheelbarrow up and down the steps?  Use the wheelbarrow ramp, of course.

Two steps down a grass ramp to a grass landing. How do you navigate your wheelbarrow up and down the steps? Use the wheelbarrow ramp, of course.


Grass steps with stone risers welcome visitors coming in from the Lych Gate on the right  This stairway is really a series of little terraces that tame the slopes converging in that corner of the South Lawn.

Grass steps with stone risers welcome visitors coming in from the Lych Gate on the right This stairway is really a series of little terraces that tame the slopes converging in that corner of the South Lawn.


It's a stair, a ramp, a runnel, a runway. It shows you where to go, and incidentally holds level the top edge of the South Lawn and Oak Terrace.

It's a stair, a ramp, a runnel, a runway. It shows you where to go, and incidentally holds level the top edge of the South Lawn and Oak Terrace.


And, of course, can't leave out the Blue Steps, Mabel Choate's path down to her cutting garden.  Riser/tread ratios change with each step; high risers and short treads at the top of each run graduate into low risers and long treads by the bottom, so that each white stair rail above the step noses scribes a parabola in the air, rather than a straight line.

And, of course, can't leave out the Blue Steps, Mabel Choate's path down to her cutting garden. Riser/tread ratios change with each step; high risers and short treads at the top of each run graduate into low risers and long treads by the bottom, so that each white stair rail above the step noses scribes a parabola in the air, rather than a straight line.

Naumkeag, the Choate family estate now owned by The Trustees of Reservations

Read Full Post »

One consideration in how we define slope — the audience to whom we’re communicating. When I’m discussing the pitch of a walk with another landscape architect, I’ll talk about it as a percentage (“From the wall to the driveway the walk slopes at 3 percent, with a consistent 2 percent wash”) When a contractor looks at a slope, he tends to see it as a ratio (“So I’ll set the stones to slope a quarter of an inch per foot, then”). This switching back and forth was confusing to me at first, but then I realized that the language (slope) is the same; it’s simply a matter of mastering the various dialects (ratios, percentages, decimals).

(Several years ago I had a meeting with one of the chief engineers on Boston’s Big Dig, about some grades one of the downtown tunnels. We chatted for a while, and he batted around elevation numbers with amazing facility. For me, physical slope is easier to visualize than numbers, and I still work at making the conversion from physical form to numeric form. I asked the engineer how he understood slope — as form, or as numbers — and he told me that the numbers were an easier way for him to conceive of it. He could read the slope simply from seeing the sequence of station numbers. It was remarkable to me that he could envision the nature of the grade this way, and showed yet another way of conceiving of slope.)

Read Full Post »

To digress just a little from the line discussion: That Parc Citroen photo puts me in mind of the Cornell Arts Quad, around which are ranged some of Cornell’s most historically and academically significant buildings. The Arts Quad is huge (obviously not what it has in common with the Parc Citroen lawns shown), and there is a several-foot (eleven feet?) grade change from east to west, along its short axis.

Cornell Arts Quad looking north to south.  The tipped plane displays the lawn more prominently to those walking along the west side and looking east, as an open box of candy looks more appetizing when held at a slant to display its contents better.

Cornell Arts Quad looking north to south. The tipped plane displays the lawn more prominently to those walking along the west side and looking east, as an open box of candy looks more appetizing when held at a slant to display its contents better.

When I was a student there in the late 80s, and in the throes of learning how to analyze sites, I realized that the Arts Quad’s tilted plane created a perceptual wall for anyone walking along the west side, looking east and uphill. Standing at the bottom of the lawn and facing east, your eye perceives more lawn even than is actually there, because the plane is slanted rather than flat. In Parc Citroen, the tipped planes of lawn feel similarly more available to the eye from the walks along their low edge.

Using this kind of quiet grade manipulation can let you create a sense of greater green space than may really be available. Horizontal planes give you two axes — horizontal and vertical — to read, while tilted planes give you a more complex experience. I think that controlling the ground plane’s edge makes the experience more readable, as in this Halvorson-designed tilted plane at the Boston Federal Reserve Bank,

Tilted plane of lawn at Boston's Federal Reserve, with South Station behind.  This cylinder of stone and grass is actually part of the Fed's security system -- no one can drive a truck through it to hit the bank's glass walls, just to the left.  But you don't read it as a giant bollard; you read it as a big pad of lawn, elevated and held out to your eyes on a stone tray.

Tilted plane of lawn at Boston's Federal Reserve, with South Station behind. This cylinder of stone and grass is actually part of the Fed's security system -- no one can drive a truck through it to hit the bank's glass walls, just to the left. But you don't read it as a giant bollard; you read it as a big pad of lawn, elevated and held out to your eyes on a stone tray.

or at Park Citroen. Where the plane continues to buildings (which accommodate the grade change), as in the Arts Quad, the effect is more subtle.
Now that's a controlled edge.

Now that's a controlled edge.

Manipulating the ground plane with a wash is a fine way to tweak how a space is perceived, and to give it more quiet complexity.

Cornell Arts Quad photo taken by Anjum and supplied courtesy of Flickr.

Read Full Post »

Older Posts »