The NCARB Exam Guides for each division are required reading. In each Exam Guide, NCARB provides a sample passing and failing solution to the graphic vignette(s) in that particular division. Unfortunately, candidates often think that these passing solutions are ideal, when in fact they are merely "passing." Some "passing" solutions contain significant errors. What's more, not all of the errors in the failing solutions are noted.
Be sure you have the most recent version of the Exam Guides, effective August, 2015
We have addressed these inaccuracies, omissions, and poor design decisions in the list below. If you have found an error you feel should be added to the list below, please let us know:
Site Zoning Vignette:
There is only one "correct" solution to this problem. Errors in the passing solution are addressed in the text below the solution.
Site Grading Vignette:
The sample passing solution violates the requirement that the slope of the regraded portions of the site must be at least 2%. The minimum slope is likely to be along the centerline of a new swale, from point to point. Use sketch lines to trace the centerline of a swale. If the centerline between points is comprised of multiple line segments, add the lengths of the line segments between the points (contour 105' to contour 106', for example). To maintain a 2% minimum slope, the sum of the lengths of the line segments must be <50’.
To correct this solution, simply move the points of contour line 105’ closer to the points of contour 106’. Then move the points of contour line 104’ closer to the points of contour 105’. This may require the addition of swale points to contour line 103’ to maintain a 50’ maximum between the points of contour lines 103’ and 104’.
Site Design Vignette:
In the passing solution, the sidewalk from the Pedestrian Plaza to the main entrance of the Restaurant crosses the access drive from Bentley Avenue. In my opinion this clearly violates the program requirement for a "continuous walkway system." Although it defies "sound design logic" NCARB says that it is acceptable, "just try not to do it too often."
The two new Conifer(C) trees at the southeast corner of the parking, and the two new 'C' trees at the northeast corner of the Restaurant are unnecessary. More new 'C' tress than necessary are used to block wind to the Pedestrian Plaza. However, the northwest corner of the Pedestrian Plaza is unprotected from wind.
The Pedestrian Plaza is required to have, "noonday solar access." Because of the shadow created by the Office Tower, the southwest portion of the Pedestrian Plaza does not receive "noonday summer sun."
The Pedestrian Plaza is approximately 1,000 s.f. undersized
The Restaurant is required to have a view of the Pond, which is questionable.
The 'buffer' paving in the center of the parking 'loop' is acceptable but not required by the program.
Please note: In July, 2013, NCARB made some changes to the Site Design program. One of these changes was program item #2, "The Restaurant and Office Tower shall be at least 210 ft apart."
In revising the program, it appears that NCARB neglected to remove the third bullet point under program item #13, "Buildings must be separated by a minimum of 20 ft."
Obviously, if your solution satisfies program item #2, then the third bullet point under program item #13 is satisfied.
In the Failing solution, the Office Tower and the Restaurant are not "at least 210' apart." The Pedestrian Plaza is approximately 1,000 s.f. undersized. The south west portion and the north east corner of the Pedestrian Plaza do not receive noonday summer sun.
In the passing solution, the west handrail at the bottom of the stair comes dangerously close to reducing in the width of egress. In order to maintain the egress width, the distance between the end of the handrail and the north wall must be at least equal to the clear width between the handrails on the stair, in this case 52". As a potential code violation, this could be a significant error. The 12” extension could be turned 90 degrees to the west to avoid the issue.
At the 3" landing, the east and south guardrails have the required 12" extension. However, NCARB has said that a continuous guardrail is necessary because it's dangerous for a wheelchair descending the ramp, and it's tripping hazard. How one could trip from a +3" landing up and over the guardrail at the upper ramp is unimaginable. Regardless, put a guardrail there. As contradictory as it sounds, NCARB has also said that there is "no penalty for excessive railings on this vignette." But, if you do add an "excessive" railing, it must satisfy all code issues. So be careful.
In the passing and failing solutions, per NCARBs code, the wall-side handrail on the upper ramp from 30" to 25", is unnecessary Because the rise between landings is 6" or less.
In the failing solution, the handrail extension on the north side of the lower ramp reduces the egress width.
Stair Design Vignette:
In the passing solution, the problem is solved without using the cut stair tool. The entire solution is shown on the upper level, which is fine. However, knowing how to use the Cut Stair tool correctly is critical. On test day your solution may require it.
Roof Plan Vignette:
In the passing solution, on the east edge of the upper and lower roof the downspouts are partially visible, but the gutters are cut off.
Candidates often establish the minimum elevation of the low edge of the high roof based on the following: Elevation of the high edge of the low roof (14'-0") plus the clerestory (24") plus the thickness of the upper roof assembly (18") = 17'-6". The 19'-0" roof elevation at the south west corner of the Exhibition Room is higher than the required minimum. Don't let the 19'-0" dimension confuse you. In this instance, using the minimum of 17'-6", while maintaining minimum roof slopes of 6:12, would require moving the ridge to the east in order to maintain a minimum height of 9'-6" at the east edge of the roof (at face of chimney).
The roof elevation at the north east corner of the Exhibition Room is obscured by an arrow. It reads 10'-0".
In the failing solution, the upper roof slope is lower than the minimum allowed by program.
Interior Layout Vignette:
The Turning Space (a 60" diameter circle) required in each room, may NOT overlap a door swing. So don't do it!
Here's the problem. A candidate may never realize this prior to testing. The information is not part of the program requirements for the vignette. In the program, this is the code that NCARB says justifies their position on the door swing/Turning Space overlap.
"1. The space required for a wheelchair to make a 180-degree turn is a clear space of 60 inches in diameter."
A door "swing" is not an obstruction. The space on the pull side of a door is "clear" unless the door is being opened or closed. In the absence of a specific NCARB code requirement prohibiting the overlap, the issue is ambiguous at best. Therefore, a candidate must apply "sound design logic." In addition to the fact that ADA specifically allows the overlap, it's not mentioned as an issue in the NCARB Exam Guide. Regardless, just don't do it.
Warning! Persnickety content ahead.
The sample passing solution in the Exam Guide seems to violate the Turning Space requirement. The area in the northwest corner of LCR appears not to accommodate the Turning Space. However, lay out the LCR similarly in the actual NCARB software, and does fit! In the end, a simple change in the furniture layout makes the whole issue irrelevant.
Additionally, the west chair at the Table For Four (TFF) in JO is likely inaccessible. 3ft is required between the edge of the table and the wall.
In CR, the copy machine would be better located on the north wall. Then, shift furniture on the south wall to the east. This would eliminate the south-east inaccessible (dead) corner.
In the failing solution, the space behind the secretarial desks is inaccessible.
Building Layout Vignette:
In the passing solution, avoid L-shaped rooms if possible, see GR and LM.
The location of TR between EE and E is not 'sound design logic' and causes L-shape for GR.
The double doors at the Lobby entry are acceptable but only one door is required.
Door at the east end of CO (1st Floor) is unnecessary. Exiting through the east stair is sufficient.
CR has two doors. Only a single door to the CO is required. The door to the east may be an attempt to satisfy the requirement that CR be, "Near Multi-purpose Room."
In the failing solution, the text below 'floor 1' says, "table/chair storage (TS) room does not directly connect to the circulation system as required by the code." However, it does connect to the corridor (CO).
Additionally, TS has two doors. Only a single door to the CO is required. The door in the north wall to MP may be an attempt to satisfy the requirement that TS be, "Near Multi-purpose Room."
Structural Layout Vignette:
In the passing solution, while the use of bearing walls and lintels is acceptable, many candidates find this problem easier to solve using only steel columns and beams.
In the sample failing solution, Upper Plan, because the "inefficient" joists span in the long dimension, the beam over the clerestory is unnecessary. A joist is sufficient.
Mechanical & Electrical Plan Vignette:
In the passing solution, the rigid duct exiting the supply riser may run straight toward the south wall of the Supply Closet. There is no need for it to jog to the west and then run south along the west wall.
The spacing between the long sides of the 2' x 4' fluorescent light fixtures in the Architect's Office is incorrect.
In the Reception/Secretary, Architect's Office and the Drafting Studio the ceiling grid is off center.
Return-air grilles in the Conference Room and one grille in the Drafting Studio are not supported on three sides.
In the failing solution, the spacing between the long sides of the 2' x 4' fluorescent light fixtures is incorrect in the Architect's Office.
Accent fixtures are too far from the west wall of the Architect's Office.
Rigid ducts exiting the supply riser don't need to jog to the west. They are already parallel to the joists.
The text below the failing solution says, "The one supply diffuser in the Reception/Secretary area sits directly under the rigid duct but is not connected by flex duct as required." Although one supply diffuser is missing the flex duct, two supply diffusers are shown, neither of which are directly under the rigid duct.
Building Section Vignette:
For clarity, the passing and failing solutions are drawn so they do not overlap the floor plans. This is acceptable but takes more time than drawing the solution directly over the plans.
In the passing solution, if we're following "principles of sound design logic," the interior bearing wall should not bear on the 1st floor slab, but directly on a foundation wall below. The slab should stop on one side of the interior foundation wall and continue again on the other side. However, NCARB has said that because this vignette is diagrammatic, and not a construction document, the way it is shown is fine. Ceiling to slab dimensions are much more critical.
The interstitial spaces are noted, "Correct Depth", but what are they? Here are the numbers;
Laboratory - Slab Thickness = 4" + Joist Depth=32" + Duct Depth=20" + Lighting Depth=8" for a total of 64"
2nd Floor - Slab Thickness = 4" + Joist Depth=24" + Duct Depth=20" + Lighting Depth=8" for a total of 56"
1st Floor - Slab Thickness = 4" + Joist Depth=24" + Duct Depth=24" + Lighting Depth=8" for a total of 60"
In the failing solution, the interior footing should be shown directly up against the bottom of the slab.