建筑设计与景观界面e Word 文档

Design architecture and landscape interface

Abstract:

As borders between buildings and their natural surroundings become more

permeable, experts see green surfaces and related features as functional components of

building systems, with evolving standards, clearer metrics, and definable

has been prototyping designs far longer than humans have. And as architects strive to

keep up with the rapidly evolving world of green-building standards, some of them are

looking to exploit that experience by bridging the gap between nature and the built

environment. The end goal: creating a functional interface between the two that improves

building performance.

Key word:

Design architecture, natural surroundings, Systematizing Interface Standards

In the second half of the 20th century, buildings and landscape became disconnected.

Many architects saw nature as an unruly force to be excluded at all costs. Nonetheless, a

small but vocal group maintained interest in the interplay of the built and natural

environments. And today, architects increasingly see biomimetic and biophilic approaches

as practical strategies.

Contemporary systems that exemplify this interplay include green and blue roofs,

green fa?

ades, living green walls, porous pavements, and associated systems for

managing water and soil. But putting these green machines to work isn‘t plug

-and-play; it

calls for patient cost-benefit assessment. Well-deployed natural features can improve

water management and thermal control and reduce operating costs, but they are not a

panacea.

―We have to break it down three ways,‖ says Signe Nielsen, a principal at the New

York landscape architecture firm Mathews Nielsen. ―We‘ve got the up

-front capital costs,

the long-term maintenance cost, and then the long-

term benefit to society.‖ In

communications with clients, she recommends, ―you ought to be prepared for developing

an opinion on all three and backing it up with facts and dollars.‖ Specific metrics exist for

irrigation, stormwater control, energy modeling, and benefits produced by trees, among

others.

Architects, Nielsen notes, can employ resources such as the National Tree Benefit

Calculator, which takes location, species, tree size, and nearby land-use categories as

inputs, and returns estimates of cost savings for stormwater control, electricity and

natural-gas savings, air quality, property value, and carbon reduction as outputs. Related

instruments exist for irrigation calculations in certain regions, but shading, thermal, and

cost data require site-specific calculations.

These measurements can also be a reality check. Nielsen recalls writing a manual for

green roofs in New York and noting that a 4,000-square- foot green roof with 6-inch-tall

foliage does wonders for stormwater retention, but, because oxygen production is a

function of leaf mass, the roof‘s potential by that metric was equivalent to that of a single

tree. ―I remember trying to make my case to the city, and they said, ?You know, if we just

planted four trees, it would cost us a

tenth the cost of a green roof,‘‖ she says. And while

the argument over including such features rarely rests on a single variable, it is important

to know which will resonate with decision-makers.

Systematizing Interface Standards

The LEED system, says Frederick Steiner, Assoc. AIA, dean of the School of

Architecture at the University of Texas at Austin, ―did a pretty good job with buildings, but

once you got outside the building envelope, there wasn‘t much there. Basically it was ?use

native plantings; c

onserve water,‘ both of which are worthwhile goals, but it doesn‘t go into

very much depth.‖ New site

-scale standards are evolving. The American Society of

Landscape Architects (ASLA), the University of Texas‘s Lady Bird Johnson Wildflower

Center, and the United States Botanic Garden have formed an interdisciplinary

partnership, called the Sustainable Sites Initiative (known as SITES), with a

complementary voluntary rating system for sustainable landscapes, with or without

buildings.

―The USGBC, a stakeh

older in the initiative, anticipates incorporating the SITES

guidelines and performance benchmarks into future iterations of the LEED Green Building

Rating System,‖ reports Mark Simmons, director of the Wildflower Center‘s Ecosystem

Design Group and a memb

er of the SITES Technical Core Committee. SITES, Simmon‘s

colleague Steiner says, is organized around the idea of ecosystem services, the

accounting of processes that nature provides gratis: clean water and air, oxygen, climatic

mitigation, plant pollination. And there are other groups exploring these ideas as well.

Jeffrey L. Bruce, the chair of Toronto-based Green Roofs for Healthy Cities

—

a group that

increases awareness of the economic, social and environmental benefits of green roofs

and green walls

—

als

o recommends the Cascadia Green Building Council‘s Living

Building Challenge, which is ―projecting a standard that may take us decades to reach.

They‘re looking at net

-zero energy, net-zero carbon, net-

zero water,‖ he reports. ―Totally

off the grid.‖

The t

rick is to determine which interfaces are appropriate. ―Why do you want a green

roof?‖ Simmons says. ―What do you want your roof to do?‖ Beyond aesthetic appeal,

choices involve thermal control, stormwater management, externality mitigation, and

biodiversity. Extensive green roofs, with a light vegetative layer, differ from intensive roofs,

with thicker soil, sturdier structures, and more ecological complexity. David R. Tilley,

associate professor at the University of Maryland‘s Department of Environmental

Science

and Technology, estimates that green roofs are ―about five to eight years ahead of the

greenwall industry in terms of market penetration, popularity, standards, and size.‖

―Designers should ask clients, ?Which of these do you want: just aesthetics,

stormwater, biodiversity?‘ ‖ Simmons says, then tailor designs to performance. ―Then the

onus is on the industry to say, ?OK, you live in Atlanta, you‘re limited to 100 pounds per

square foot, you want to absorb a half-inch of rainwater, and you want to attract butterflies.

OK, those are the specifications; thank you, we‘ll go back and design it and give you a roof

that can do that.‘ Now, that implies a lot of accountability.‖

Light, Shade, and Energy

Shade is vegetated surfaces‘ primary service to the

ecosystem. ―Once you have a full

canopy developed that‘s three to four years old, and it‘s matured,‖ Tilley says, ―you‘re

looking at probably a 95 percent reduction in the solar load.‖ Canopy is measured

according to leaf-area-index (LAI) relative to wall area; for each unit of LAI, sunlight

decreases by about half. Effects on interior temperatures depend heavily on insulation: If

walls already have a high R-value, even dramatic reductions in LAI will cut temperature

only slightly, but at low R-values, a dense canopy reduces cooling costs appreciably.

Replacing black asphalt with vegetation raises rooftop albedo, and evapotranspiration can

add humidity to an urban atmosphere; both help mitigate heat-island effect.

The converse benefit

—

reducing heating loads with passive solar energy through the

use of green fa?

ade systems

—

calls for deciduous species, which lose their leaves and

thus allow light to penetrate into the building during winter. Native plants known to thrive

under local conditions (climate zones, pest resistance, and soil compatibility, for instance)

are preferable; consulting with local botanists is advisable.

Every region has its success stories and its problem children with regard to the plant

varieties installed in a project. Maryland-based Tilley warns against using English ivy

(Hedera helix), which adheres tenaciously and is aggressive enough to move beyond its

support structure and enter a building through windows. Nielsen, based in New York,

identifies wisteria as another potential monster: attractive and fragrant, but capable of

growing 70 feet tall and forming a woody trunk powerful enough to crush metal and tear

roof leaders off a building.

In French botanist Patrick Blanc‘s vertical gardens, mesh

-supported systems of felt,

pipes, and valves deliver hydroponic nutrients to roots by capillary action. Maintenance is

considerable: soil dries out faster in containers than at grade. ―Those are art pieces,

effectively,‖ says Denise Hoffman Brandt, landscape architecture program direc

tor at the

Bernard and Anne Spitzer School of Architecture, City College of New York (CCNY).

―They‘re extraordinarily expensive to install and maintain. A modular, low

-maintenance

greenwall system hasn‘t hit the market yet.‖

The alternative

—

green fa?

ad

e systems or lightweight trellises on or near a building‘s

exterior, with plants rooted in ground- level soil

—

offers thermal and other benefits with

lower operating costs and fewer structural complications. These systems can also be

deployed to integrate pl

antings when ―you‘re dealing with not as much available plan

space to incorporate gardens or large specimen trees,‖ or when retrofitting an existing

project, says James Sable, vice president of Los Angeles

–

based Greenscreen. On the

whole, green fa?

ades are more reliable on lower stories or on roofs than on a full

skyscraping scale: With a few exceptions in tropical climates (such as towers in Southeast

Asia by Malaysian architect Kenneth Yeang, Hon. FAIA), wind loads can make vertical

green structures above four or five stories problematic.

译文：

建筑设计和景观界面

摘要：

随着建筑和自然环境之间的边界日益渗透，

与 之相连的标准不断发展，

指

标愈加明晰，

效益更易定义，

专家把绿色外观及其相关特征看作了建筑系统的功

能构成部分。

在人类进行原型设计之前，

大自然很早就这样 做了。

当建筑师们努

力跟上以绿色建筑标准构建的日新月异的世 界时，

他们中的一些人正努力缩小大

自然和建筑环境之间差距。

终极目标就是：

创造一个连接自然和建筑的功能交界