AC condensers and mini-splits in the Marigny and Bywater historic districts
The Marigny and Bywater are full-control HDLC districts, so any condenser, mini-split, or line set that can be seen from the street needs a Certificate of Appropriateness. The houses make the rules hard to follow. HDLC’s district sheets describe Marigny Creole cottages “built without front yards” and say most Bywater buildings “are set directly on the street” (Historic Districts, January 2019). With no front yard, a side alley is visible from the sidewalk for most of its length.
Rules checked October 20, 2026, against the HDLC Design Guidelines. The Marigny was designated in 1978 and Bywater in 1993. Both use the same full-control rules.
Where the condenser goes on a cottage or shotgun
The HDLC requires ground units in a rear yard, “or when this is not possible, at a side yard,” and requires screening for any ground unit visible from the street (Site Elements, page 10-9). On these lots that usually means:
- Rear yard first. It’s the default, even when it means a longer line set to an air handler at the front of a shotgun. Check the condenser’s maximum line length before settling on the spot.
- Side alley, set back and screened. If the rear won’t work, put the unit as far back down the alley as it’ll go and screen it with a gate, fence, or lattice. The City’s zoning rule also applies here: the unit has to be two feet off the side lot line, with that two feet open to the sky (CZO 21.6.T). Some Marigny alleys aren’t wide enough for both a condenser and that clearance. The condenser placement guide covers the zoning side.
- Never in front. Zoning bans ground units in a front yard anyway. Here the front is often the sidewalk itself.
Many Bywater houses are double shotguns, so a replacement often means two condensers, one for each side. Grouping them together at the rear, with the lines organized, makes for an easier review than one unit at each side alley.
Mini-splits on cottage walls
Mini-splits are common here. The guidelines name them: ductless mini-split condensers “should be installed in a visually unobtrusive, and rationally organized manner,” including on porches and galleries (page 10-9). The review table gives staff approval to an unobtrusive wall-mounted unit at least 10 feet back from the street-facing wall.
On a house built at the sidewalk, that 10 feet is measured from the front of the house, which is the property line. The first 10 feet of side wall are off limits for a staff-level approval, however tidy the install.
The line set matters as much as the condenser. “Exposed wall-mounted electrical conduit, piping … and devices should be minimized” (page 10-9). On a raised cottage, one way to keep the lines out of sight is to bring them through the floor and run them under the house to the rear. A line-set cover down the side wall is the alternative. Abandoned window units and old line sets should come out, and the wall should be patched to match.
How long it takes
HVAC is on the HDLC’s Express Lane. A complete application that meets the guidelines can get its approval in 1 to 3 business days. A complete application includes a site plan with the equipment locations, spec sheets, and photos.
| Area | What the commission reviews | Parcels | HVAC permits | Mini-split share | Median days to issue |
|---|---|---|---|---|---|
| Faubourg Marigny | Full control | 1,649 | 188 | 12.2% | 8 days |
| Bywater | Full control | 2,208 | 317 | 9.1% | 9 days |
| Marigny and Bywater | 3,857 | 505 | 10.3% | 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 |
City permits for one- and two-family houses applied for since 2024 took a median of 8 days in the Marigny and 9 days in Bywater, from application to issue. Outside every historic district the median was 3 days. The count is for the whole mechanical permit, so the HDLC is only part of the wait.
Mini-splits were 12.2% of house HVAC permits in the Marigny and 9.1% in Bywater since 2018. That’s several times the 2.3% outside the districts. Among districts with enough permits to compare, only the French Quarter has a higher share than the Marigny.
One mapping note: the Bywater historic district is larger than the neighborhood the City’s maps call Bywater. Most of its permits are on parcels the City’s neighborhood map puts in St. Claude. The HDLC boundary, not the neighborhood name, decides whether a house is reviewed. Check the address on the City’s historic district map.
The French Quarter, just upriver, is reviewed by a different commission with stricter rules. See the French Quarter page.
Sources
- City of New Orleans HDLC — Historic Districts, Faubourg Marigny and Bywater district sheets (January 2019)
- 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 — Express Lane
- 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