Course Number: NAN08A Course Title: Design of Large Exterior
Openings
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Course Learning Objectives:
The objective of this course is to describe
possible design solutions for large wall areas that can open. The designer will
learn about:
Challenges associated with large openings
Variations/flexibility of large opening glass
walls
Successful Design Solutions for large openings
Challenges of Large Openings:
Large openings present
several architectural challenges. To name a few:
Structure/Openness - The
balance of structure vs. openness
Weather - Preventing
weather infiltration (water, wind, heat)
Operation/Geometry - Smooth
function
Structure/Openness:
Architecturally speaking,
openness can be described as the ratio of space vs. solid. One challenge with
large architectural openings is that large openings in the exterior envelope
require either a heavy horizontal structural member (such as a beam) that
can meet maximum allowed deflection under full loads
or repetitive vertical
structural members (such as columns).
With a large opening, the
compromise is a choice between an unconventional structural system or a series
of disruptive columns.
Although the unconventional
structural system might provide the desired clear space the cost might be
prohibitive. Whereas if the designer uses conventional structural members
(beams & columns) an opening that exceeds the standard column spacing might
be obliterated by columns. Structural constraints are just one challenge
of large architectural openings.
Weather:
Another concern associated
with large exterior openings is weather infiltration. Theoretically, the
potential for weather infiltration into a building is a multiple of the number
of penetrations in the building envelope. To illustrate using a
simplistic example, the potential for infiltration into a secured envelope (no
fenestration)
should be less likely than
infiltration into a penetrated envelope (with fenestration)
Weather presents a
measurable challenge with any opening that can be magnified when using large
exterior openings.
á
Fortunately, the fenestration industry uses standard physical tests that measure air and water infiltration and structural loading.á Although test results vary and do not guarantee adequate performance under all circumstances, the designer is challenged to determine whether test results for a certain product is adequate for his particular site conditions.
In the same way that larger
openings challenge weather resistance, large opening geometry affects the
operation.
Operation/Geometry:
Further complicating the
use of large exterior openings is geometry. As geometry grows more
complex
a
straight line
angled
line
curved
line
the physical operation of
door or window elements conforming (or in many cases not conforming) to
the geometry grows increasingly more complex as well. So, in order to
successfully design a solution for large exterior openings, the designer needs
materials that are tailored for large openings.
A Solution for Large Exterior Openings:
The opening glass wall
One such material designed
for large exterior openings is an opening glass wall. Usually the term
ôwallö in construction terminology is an architectural partition with a height
and length greater than its thickness; used to divide or enclose an area.
In contrast to the image
above, this definition does not restrict the term "wall" to a solid
wall. In fact, walls often include glass partitions of the
"storefront" variety. Now, combine the storefront appearance
with a folding door or operable partition & you have an opening glass
wall. In essence, an opening glass wall is a fully functioning wall
component that is operable.
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A glass wall is a
combination of door leafs, either connected or not connected used as a design
element to achieve a degree of enclosure (security or weather) & expansive
openness; depending on the desired function of the space involved. An opening
glass wall is designed as different systems. For simplicity, & to better
explain the different systems, the opening glass wall is divided into 2
categories. The first is the folding system & the second is the individual
panel sliding system.
The folding systems are panels
that are hinged together at each panel and form a contiguous train. The train
assembly, which is supported by way of running carriages in a roller-track, can
be located either at the top or bottom of the system frame, depending on the
system. Hence the ôTop Hungö systems and ôFloor Mountedö systems.
The running carriages in the roller-track allow each pair of panels to
slide and fold.á For a Top Hung system,
another track at the bottom is needed to guide the sliding panels within the
opening.á A similar track at the top is
needed for the Floor Mounted system.á
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This train assembly does
not need to be continuous in the opening. It can be divided into some
panels folding to the right side jamb and some panels sliding to the left side
jamb. With an odd number of panels to one side jamb, the first panel to
be opened will be a swing panel.áá
Repetitive multiple point locking between each pair of folding panels
provides the structural strength and security even for very wide openings.á It also allows the unit to be fully or
partially opened.á Standard locking
options are available for the swing panels so they can be used like standard
egress doors.
Depending on system and
glazing, panels can be 3 or more feet wide each and 8 feet high.á Taller panels may be possible, but then each
panel will need to be narrower.á Custom
sizes are standard as long as they are within the maximum size chart for each
system.á Large openings up to 30 to 40
feet wide with 12 or panels are possible.
Generally, the folding
system is available in either wood frame, aluminum frame, aluminum clad wood
frame & all glass.
Visual Examples:
The animations in this
course are resource intensive. Clicking the link below titled "Animation
1" will load another page. You need the Macromedia Shockwave Player to
view these animations. Animations run best on a high speed connection. To see
the animation for the folding system, double click the image title ôAnimation 1ö.
Design Features:
Folding System design
features of a folding opening glass wall are:
o Walls can be quickly opened
& closed
o Units can be fully or
partially opened
o With an odd number of
panels on one side, a single swing door is possible. With an odd number
of panels on both sides, a pair of swing doors is possible.
o A multitude of stacking
configurations, as well as inward or outward opening options, is available.
o All structural loads are
within the plane of the opening
o All panels are stacked
within the opening, so no auxiliary track is needed outside the opening.
o Top hung and floor mounted
systems are available to accommodate different building conditions.
o Variations are paired panels
(pairs of panels not hinged to the side jamb and/or to each otherá & center pivot (units not completely
folding inward or outward) options
The individual panel sliding system
is composed of separate panels. In the closed position, both of these systems
look virtually the same. The greatest difference is how each system opens &
how the door/window is stored in the open position.
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In individual Panels
Sliding Systems, instead of the panels being linked together via a train
assembly, each panel is a separate entity unto itself. It is usually a top hung
system with 2 running carriages on each panel.á
No guide track is needed.á Unlike other
types of sliding systems, all panels in the opening are on a single track.á A unit is opened by sliding panels through a
ôswitchö in the upper track leading to the stacking of the panels in a stacking
bay.á This system offers the most
flexibility when it comes to stacking as the variations are virtually
limitless.á
Repetitive multiple point
locking between panels provides the structural strength and security even for
very wide openings.á
Visual Examples:
To see the animation for
the individual panel sliding system, click the link titled ôAnimation 2ö.
Now that you understand the
2 types of systems & have seen examples of their operation, the next
section further describes the system flexibility.
Swing Panels:
For ease of quick egress in
an individual panel sliding system that is in the closed position, swing
panel(s) can be included by hinging panels to either or both side jambs.á However, for some systems, a sliding panel
that is in the closed position can convert and function as a regular swing
panel.á This is called an incorporated
swing panel.áá For an illustration of the
incorporated swing panel operation, watch Animation 3 below: The incorporated
swing panel is the middle (3rd panel). Various configurations will allow
one or more incorporated swing panels.á
The actual location of the swing panels might vary depending on the
number of total panels in the system and location of the switches.
Multitude of Configurations:
Unlike the folding system,
there are no restrictions on the number of panels in a individual panel sliding
system.á Hence openings as large as over
100 feet are possible.á The only
restriction would be the required structural support for the system.á
While stacking for the
folding system is restricted to be at either end of the opening at 90 degrees,
panels in the individual panel sliding system can be stacked virtually
anywhere.á In the opening, outside the
opening, in a pocket, in a closet 50 feet away û no restrictions provided that
there is adequate support for the upper track and panels that would extend to
the stacking space.
In the individual panel
sliding system, there are two types of systems û one with running carriages
with horizontal wheels (HSW) and the other with vertical wheels (VSW).á Both types have generally most of the same
features, except that the vertical wheels in the VSW system can only move
through a 60 degree switch which makes the stacking options more restricted.
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Panel System - Interior |
Folding System - Exterior |
Folding System - Interior |
Some Possible Individual Panel SLIDING SYSTEM Stacking Options
Click
the link titled "Animation 3" to see one possible stacking
option.
Panel Variations:
Opening glass walls are
called a "system" because if specified correctly, the system is a
coordinated glass wall. This means that with compatible manufacturers the
opening glass wall possibility is expanded to encompass various folding doors
and folding window combinations, matching swing entry doors, transoms, side
lites, and corner posts.
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Folding System or Individual Panel System:
As is
the case with any design, the decision to use the folding system or the
individual panel sliding system is usually determined by the advantages.
Most solutions are solved with the folding system but each system has its
limitations & advantages.
Design Solution 1:
Recording studio:
Design
requirements: Individual recording, asynchronous group recording or synchronous
group recording all in the same studio. Requires sound separation.
Solution:
Surprisingly, the solution for this scenario was an opening glass wall.
Most designers believe that glass walls are not a good solution when acoustic
privacy is desired. But, certain opening glass wall systems (with
insulated laminated glass) offerá good
sound attenuation. Using the opening glass wall permitted different
recording artists to record their individual songs without interference from
surrounding artists. But, the opening glass wall also offered the added
benefit of group recording either together or separate. As a bonus, the
opening glass wall permitted visual coordination with acoustic privacy.
The wall (in the closed position) permitted visual synch without significant
sound intrusion.
The
recording studio is a specialized application but a similar solution is
partitions in restaurant interiors to separate a "party" room from a
serene dining area. This application permits the room to feel open yet
maintain separation between a potentially jovial crowd & a more sedate
clientele. Most importantly, opening the wall allows the spaces to expand
for larger entertainment or dining areas.
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Glass walls can also be
used for entry
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Design
Solution 2:
Restaurant/Cafe
Design
Requirements: Fair weather dining; simultaneous interior & exterior
dining.
Solution:
It is common for a restaurateur to provide "cafe" style dining where
patrons have the option (climate permitting) to dine "al
fresco". The dining room or restaurant application above is not
limited to interior spaces. There are multiple design options for
exterior/interior dining arrangements. The objective is to allow unobstructed
access to outdoor dining, yet provide weather protection for times when
seasonal fluctuations make outdoor dining less palatable. The design solutions
are nearly limitless but a few options for functionality & weather
protection include multiple swing doors (like paired French doors), sliding
glass doors, overhead rolling doors, & opening glass walls. Using the
opening glass wall as an example, the animation below illustrates the mix of
exterior & interior space to form a dining arrangement for all seasons.
Animation 4 shows an example in a restaurant setting.
The
solution is equally applicable for an entrance
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or a
fully open facade
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Design Solution 3:
Which situation is better for the folding system instead of the
individual panel SLIDING system?
There are
situations where an individual panel system is the better option. First,
about 85% of all design solutions can be solved by the more economical (lower
cost, easier use, faster operation, minimal structural support) folding
system. But, in situations where you need an opening without a floor
groove (U-channel), or you want the door stored out of the plane of the
opening, the individual panel sliding system is the better solution.
Often times, the best design solution is the one with which you are most
familiar. For example, if you have experience with operable wall
partitions & desire similar functionality for your large exterior openings,
the individual panel sliding solution is a natural choice.
Design Solution 4:
Open Corner
Design
Requirements: 90 degree opening with an open corner.
Solution:
For many design solutions, openness is achieved by eliminating the solid (wall)
between the structural members. The appearance is a skeletal structure
& an open envelope.
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Sometimes,
using a serpentine or curved wall provides a more pronounced openness as shown
in Animation 5.
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Where
more openness is desired, an open corner is another option.
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Design Solution 5:
Stadium Sky Box
Design
Requirements: indoor space/outdoor space or both simultaneously
Solution:
The sky box in an athletic stadium is a unique design application. One
such solution to satisfy the indoor/outdoor atmosphere is an opening glass
wall. For example, when the weather is clear & the fans want the
outdoor experience, the sky box could open completely. If there were some
fans who wanted the out door experience while others wanted to remain indoors,
the same configuration could allow an indoor area & an outdoor area.
For days when weather prevents outdoor exposure, the featured wall can provide
full containment. In the illustration below, the starting position is the
fully contained sky box. The finished shot is the situation where
different fans want an indoor or outdoor experience. Animation 7 shows the full
open position.
Design Solution 6:
Solarium or Greenhouse
Design
Requirements: Year round functionality
Solution:
For all glass structures such as a solarium or a greenhouse, an opening glass
wall provides maximum functionality for large exterior openings. During
winter months, where heat gain is desired, the room can be closed & weather
tight, but during summer months when an exterior space with cover is desired,
the wall can be partially or fully opened for degrees of separation or
openness. one example is a circular solarium
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Using the same concept as
above, a greenhouse or rectilinear solarium offers similar functionality --
whether outside --
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-- or
inside --
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Design Solution 7:
Hidden Doors:
Design
Requirements: Concealed doors
Solution:
For those occasions where the designer wants doors concealed, the individual panel
sliding systems offer multiple stacking options. Many of the potential
stacking options are ideas from designers. Basically, the individual
panel sliding systems can be stored in many different ways. The
illustration below shows how the panels can be moved completely out of the door
plane.
The photos show other options for concealing the
individual panels.
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The
list of potential solutions is virtually endless. The purpose of this
course is not to provide typical solutions for rigid design problems but
instead to expand the design portfolio in the same fashion that the opening
glass wall expands building space. Glass walls are an additional tool in
a design palette for solving large exterior opening design problems.
End of Course:
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