AC condensers in the Holy Cross historic district, including raising them for floods
Holy Cross is a full-control HDLC district, and here the AC question often comes with a flood question: should the condenser go up on a platform? The HDLC treats raising equipment as storm-resilience work with its own review rules. The placement rules for any visible condenser or mini-split still apply. HDLC’s district sheet describes most houses as single-story and “raised above grade,” set back behind narrow front yards. Some blocks are built right at the sidewalk, close together (Historic Districts, page 02-15).
Rules checked October 20, 2026, against the HDLC Design Guidelines. Holy Cross was designated in 1990.
Raising a condenser
The HDLC’s storm chapter expects equipment to move up. It says relocation “may require mounting on roofs, walls and platforms,” with screening to limit what the street sees (Storm Preparedness, page 13-7). Its review table sets the approval level:
- Unobtrusive elevation: a staff approval for every building rating.
- Obtrusive elevation: goes to the Commission on Significant and Contributing buildings, and stays with staff on Non-Contributing ones (page 13-8).
The application’s site plan has to show where ground-mounted equipment such as air conditioner units sits. The Site Elements chapter adds that raised equipment may need extra care with screening, and that electrical connections and junction boxes should go up with the unit (page 10-9).
Whether the City requires elevation is a separate question. Zoning says ground equipment goes above base flood elevation “when applicable” (CZO 21.6.T). Whether that applies to a straight condenser swap on an existing house is the permit reviewer’s call. The condenser placement guide explains the flood-zone test. Even where it’s optional, a raised unit behind the house is easier to screen than one near the front corner.
Placing it, and the mini-split option
The full-control placement rules apply as anywhere else. A ground unit goes in a rear yard, or a side yard if the rear isn’t possible, screened if visible (page 10-9). A mini-split condenser on a wall should be “visually unobtrusive, and rationally organized,” and staff can approve one at least 10 feet back from the street-facing wall. Exposed conduit and piping “should be minimized,” so on a raised cottage, run the lines under the floor rather than down the side wall.
Mini-splits are much less common here than in the Marigny and Bywater upriver. A wall-mounted mini-split condenser sits on a bracket off the ground, so getting it up out of standing water doesn’t take a platform. That’s worth weighing in Holy Cross. Put it on a rear or side wall well back from the front, where staff can approve it.
What the permit records show
| Area | What the commission reviews | Parcels | HVAC permits | Mini-split share | Median days to issue |
|---|---|---|---|---|---|
| Holy Cross | Full control | 1,198 | 140 | 3.6% | 8 days |
| All HDLC full-control areas | 12,075 | 1,523 | 8.5% | 7 days | |
| Outside every local historic district | 9,961 | 2.3% | 3 days |
Mini-splits were 3.6% of house HVAC permits since 2018, against 10.3% in the Marigny and Bywater combined.
The median house permit applied for since 2024 was issued in 8 days, about the same as other full-control districts. The slow end is slower: a quarter of permits took 32 days or more, against 15 days across all full-control areas. The permit counts don’t record why. A complete application helps: a site plan with the equipment location and height, the spec sheet, and photos. HVAC work that meets the guidelines qualifies for the HDLC’s Express Lane, with approvals in 1 to 3 business days.
For what to do around the outdoor unit before a storm, see hurricane preparation.
Sources
- City of New Orleans HDLC — Historic Districts, Holy Cross district sheet (January 2019), page 02-15
- City of New Orleans HDLC — Guidelines for Site Elements, Equipment and Systems (January 2019), pages 10-8 to 10-9
- City of New Orleans HDLC — Guidelines for Storm Preparedness & Resilience (January 2019), pages 13-7 to 13-8
- City of New Orleans Comprehensive Zoning Ordinance — Article 21, Sec. 21.6.T Mechanical Equipment
- See Dat — City of New Orleans permit records and parcel layer, compiled by parcel