Rooftop Additions

Rooftop additions have become a very popular way of adding additional space and increasing the square footage and floor area ratio on existing buildings in downtown New Orleans, particularly in the Central Business District local historic districts. It is important that the historic integrity of these structures and areas be maintained. It is equally important that additions, when allowed, contribute to the character of the area and respect the design and context of the building and the street scene to which they are added.

Definition.
A rooftop addition is defined as any new construction on top of an existing rooftop for occupiable or non-occupiable space (This includes full floor additions).

Policy.
In general, rooftop additions are discouraged on all rated buildings. However, the Commission will review applications on a case by case basis.

The Commission believes that on buildings which are rated purple (of national importance), or blue (of major architectural importance) and buildings which are red rated and could be upgraded to blue, rooftop additions are inappropriate and are strongly discouraged.

Buildings which have been rated purple are buildings that were designed by architects of national reputation; have been recognized as National Historic Landmarks by the National Park Service; are unique examples of American architectural development; or are associated with a person(s) or events of national importance. These buildings are to be preserved, properly maintained and when needed, carefully restored.

Buildings which have been rated blue are of major architectural importance and are outstanding examples of works by notable architects or builders; are unique or especially fine examples of a particular style or period when original details remain; are part of an intact row or grouping; or are noteworthy examples of a particular type of construction technique, when the original fabric of the building is basically intact. These buildings should be preserved; be protected from unsympathetic modifications, and have original facade treatments properly restored when possible.

Buildings which have been rated red are important buildings that have been altered leaving much of the exterior facade either extremely modified or covered over. However, because of their scale or basic construction, these buildings still make a notable contribution to the overall character of the area. Although placed in a lower category, the significance of these buildings should not be overlooked or minimized. If properly restored, the rating of a building in this category would be raised.

On buildings rated green (of architectural or historical importance) or those red-rated buildings that could be upgraded to green if properly renovated, the construction of rooftop additions may be allowed on a case-by-case basis at the discretion of the full Commission.

It is important to note that buildings which are rated green are buildings which are typical examples of the architectural types and styles found in the city. When buildings in this category retain their original architectural details, they make a notable contribution to the overall character of a particular area. These buildings should be preserved and when feasible, restored as closely as possible to their original appearance.

On buildings rated gold (contributing) and/or unrated buildings, the construction of rooftop additions may be allowed on a case-by-case basis at the discretion of the full Commission.

The approval of a rooftop addition on any one building or a previously approved application for a rooftop addition shall not be considered as precedents or construed to mean that new proposals will automatically be approved.

• The height of the existing building will be a major factor in determining the appropriateness of allowing the construction of a roof top addition.
• Rooftop additions shall not be allowed on structures of two stories or less, regardless of the rating.
• Rooftop additions shall not be allowed on structures of two bays or less, regardless of the rating.
  
• A rooftop addition shall not call attention to itself, nor detract from the architecture of the existing building or the surrounding historic district, streetscape, or adjacent structures.
• When rooftop additions are proposed for buildings which are adjacent to empty but potentially buildable lots, the proposal shall be evaluated as if no building will ever be built on the buildable lot.
  
• Rooftop additions shall comply with existing zoning, and shall not require the granting of a variance for height limits or floor area ratios.
  

Design Standards for Rooftop Additions
If permitted, the following design standards for rooftop additions are to be followed:

Rooftop additions shall:

1. Be limited to a maximum of 75 percent of the roof area, excluding the parapet.

2. Be limited to one story in height, with an interior ceiling height not to exceed 8 feet, except for code-required components, such as elevator overrides. Elevator equipment, mechanical equipment, and HVAC equipment shall fall within the single story, 75 percent footprint.

3. Be permitted only on buildings with existing parapets in excess of 18 inches from the highest point of the roof and on existing roofs which have less than a 3 in 12 pitch.

4. Be permitted only when set back a minimum of one full bay or 10 feet, whichever is greater, from all sides.

5. Be permitted to have a flat roof only.

6. Be permitted only when all railings, planters, and rooftop furnishings are set back far enough to only be visible from the public right-of-way at a 1,000 foot distance.

7. Be permitted only when the designs of such additions reflect the basic design, color, texture, and fenestration of the original building. The rooftop addition shall be as inconspicuous as possible when viewed from the street.

Submittal Requirements:

1. Dimensioned elevations and plans showing the proposed rooftop addition on the existing building.

2. Sight-line studies, either photographs or drawings, illustrating the massing of the addition and visibility from 1,000 feet on public rights-of-way in all directions, and showing not only the impact on the subject heading, but also on the adjacent buildings and the historic district as a whole.

3. A to-scale massing model of the addition on the existing building.

State Historic Preservation Office

Policy on Rooftop Additions

1. Rooftop additions - recommendations are made with the intent to minimize visibility and thus to minimize changes to the historic character of the building.

2. All rooftop additions should be no taller than one story.

3. Elevator housing and mechanical equipment should be no taller than one story.

4. Additions should have an interior ceiling height of 8 feet.

5. Roof framing is removed when necessary to lower the visible height of the addition.

6. Additions are set back one full bay from all sides.

7. Any additional set back is determined by the height of the parapet.

8. Railings and planter boxes are set back far enough to be invisible from the street.

9. Additions to have flat roofs to match the roof of the original building.

10. Additions should match as closely as possible the color of the historic building.

11. Additions are to be designed to reflect the basic design of the building, but with decorative elements simplified.

12. Site line studies indicate that the additions are minimally visible from any public right-of-way.