Ms. Erin Minnigan is the Director of Preservation and Planning at Preservation Society of Charleston. She previously served as BAR-S Administrator at Charleston’s Board of Architectural Review (BAR), and as Historic Preservation and Community Development Planner for the City of St. Augustine. She was closely involved in the development of Charleston BAR’s Design Guidelines for Elevating Historic Buildings (2019), an innovative guiding document and review standard for the flood retrofitting design of historic houses that gained nationwide attention.
Established in 1931 as the first historic district protected by local legislation in the United States, Charleston’s “Old and Historic District” encompasses a vibrant collection of 18th and 19th-century architecture — including many distinctive local single dwellings. However, since a considerable portion of the peninsula was developed upon landfills, flooding has historically and increasingly been a critical challenge to the city. In 2016, the city experienced a record-breaking 50 days of tidal flooding; between 2015 and 2017, the city was hit back-to-back by three major storms: Hurricane Joaquin, Hurricane Matthew, and Hurricane Irma.
This interview was carried out on Nov. 29, 2022 over Zoom.
“To that point, we realized that if we continued to deny the elevation of historic homes and disallow them to be brought up to code, it would adversely affect their long-term preservation."
Current Flood Map of Charleston’s Peninsular Historic City Center. Source: Ziming Wang based on FEMA Map Service.
Ziming Wang: Charleston’s history of major storm events and flooding can be traced as far back as to Hurricane Hugo of 1989. What pushed the recent spike of historic building elevation in the city, and made Charleston a leading policy-maker on this matter? How many historic buildings are elevated each year?
Erin Minnigan: Flooding really became a quality-of-life issue during the back-to-back storms we encountered between 2015 and 2017. As water repeatedly intruded living spaces, many homeowners would have to fully replace utility and HVAC equipment in their homes every year, just for them to be flooded again. That was when public opinions shifted towards supporting building elevation.
During these flood events, some homeowners were left with no money to further repair their homes, and had to sell their properties; but those who held out and had resources to elevate started to put pressure on BAR for policy reform and guidance.
This is because BAR had largely rejected elevation applications due to form, material and contextual concerns. Homeowners would typically seek FEMA variances when they substantially renovate their homes, so their homes would have the right to not elevate at all, or not elevate up to FEMA requirements. But to that point we realized that if we continued to deny the elevation of historic homes and disallow them to be brought up to code, it would adversely affect their long-term preservation. This crisis justifies the necessity for elevation. [1]
The number of elevation cases usually varies year by year, but over the last five years, the BAR has seen around 50 elevation applications filed in the city’s historic district.
Ziming Wang: In my interviews, many people have stressed the importance of governmental financial support in promoting the retrofitting or elevation of historic buildings. How many of the elevation projects you just mentioned are supported by financial grants or governmental subsidies?
Erin Minnigan: Yes, there theoretically is some funding from FEMA’s Hazard Mitigation Grant Program that funnels through the city’s Department of Stormwater Management, but not many elevation projects have been able to use it. Homeowners seeking FEMA grants are often denied because it takes so long from the opening of a grant application to the closing of it — and so, at some point, they’re not accepting new applications. I also read somewhere that there have only been slightly more than a handful of grant applications (from homeowners) approved in Charleston so far — it is not the official count, but does reflect the complicated process of securing a Federal grant. However, without these grants, some homeowners would have to turn to mortgage loans with high interest rates. Furthermore, it’s also not easy to get information on the availability and allocation of these funds from the local government.
Ziming Wang: The Charleston guideline consists of many creative measures — such as “piazza screening” and articulated foundation expression — to help retain the proportion and characters of historic buildings under structural elevation. How did BAR gather the necessary professional resources to make this guideline? Did the policy-making process involve collaboration with other governmental or non-governmental agencies?
Erin Minnigan: In the early stage, it was really just BAR trying to respond to homeowners’ cries for assistance by developing recommended practices. But in the process we also tried to be more collaborative — in November 2017 and March 2018, we held two workshops together with 10-15 professionals including architects, developers, contractors, and preservationists, as well as members of the public.
In the first workshop, we showed a lot of pictures of existing elevated buildings in Charleston and reviewed the existing elevation guidelines for historic buildings made in other places such as Louisiana and Mississippi, and asked attendees about their preferred design treatments used in these projects and guidelines. There was a great interest from both professionals and the public who donated their lay time to attend this workshop — and we ended up with a consensus to provide policy procedures and design guidelines for the elevation of historic buildings.
In the second workshop, we broke the professionals into four focus groups — Streetscape/Context Considerations, Site Considerations, Foundation Design Considerations, and Preservation and Architecture Considerations — to formulate more refined design rules. Few local residents showed up this time, since they already knew their elevation applications would be permitted. Nevertheless, we still had some in-depth debate on the details of the guidelines: one debate that I remember was on whether the material of a new/extended foundation should match that of the original foundation, or be differentiated from it — which connects to the twofold requirement of “Compatible but Differentiated Design” stated in the Secretary of Interior’s Standards. We finally recommended matching material and salvaged material to be used. At this point, we also produced a procedure for the elevation of “sister houses,” where the first house to be raised would set an example for adjacent houses with the same design, and would thus be reviewed under great scrutiny.
I agree that the production of this guideline is somewhat remarkable — and I hope that with more and more similar guidelines emerging across the country, policy-making today would be much more comprehensive and collaborative.
Ziming Wang: Speaking of the design of these elevation projects — is there a group of preservation architects who specialize in flood retrofitting design in Charleston? Or are they just preservation architects at-large undertaking retrofitting design commissions?
Erin Minnigan: There really isn’t an “elevation design specialist” group among local preservation architects — we are all learning this together, and nobody has done this before. Nevertheless, these architects do know local architecture well — many of them have known and worked on these historic houses for decades. So it’s in their blood to be able to come up with creative solutions, and they did a nice job extending the characters and styles of historic buildings in elevation projects.
Ziming Wang: Like 1 Water Street — the waterfront residence elevated with an elegant staircase and new arched entrance featured in the walking tour of Keeping History Above Water 2021 conference.
Erin Minnigan: Yes, it was designed by Julia F. Martin Architects. One thing I like about this design is that it kept a simple and reduced form for the new ground-level arched entrances — so they stay as a context for the original entrances lifted above, not an overboard presentation. Other architects have also designed dry-floodproofing barriers and peripheral walls around historic properties — I believe you’ve seen some of these during the walking tour.
Ziming Wang: I noticed your new role as the Director of Preservation & Planning at Preservation Society of Charleston. How different is working as an NGO director compared to working as a preservation agency administrator?
Erin Minnigan: At BAR, my role was to some extent limited to the daily tasks of reviewing applications and processing requests; however, in my current advocacy role, I’m able to work on a variety of projects. The Preservation Society is a member-based non-profit that advocates for Charleston’s preservation and development, so in this role I’ve been able to better understand what changes people desire, and to advocate on their behalf. Currently, we’re engaged in some active talking with the city’s Chief Resilience Officer to develop a citywide water plan that studies and plans water issues from all angles.
I still go to BAR meetings every month, where I express my organization's opinions about new elevation projects.
Ziming Wang: The flood adaptation of historic built environment is a complicated and highly interdisciplinary field. How can the public and professional practitioners better collaborate in this collective discourse?
Erin Minnigan: Information sharing is vital. Many homeowners may not be interested in formal “public education,” but they surely need information and guidance throughout the process of building elevation. They want to know how to get their projects approved, where they can find funding opportunities, what are the regulatory requirements and design review regulations, how the NFIP system works, and so on. Without a channel to get such information, they may feel that they’re continuously bumping into walls.
With that being said, I also feel an urgent need for professional education in this field. In the making of the BAR Guidelines, I was constantly trying to understand new information from different sources; since it’s a highly interdisciplinary arena, I do feel we as preservationists would be better off if we could get some education from emergency management professionals, flood experts, or policy-makers in other related fields. Social media may be helpful in promoting education and information exchange for both the public and professionals.
Ziming Wang: How do you imagine Charleston’s future historic streetscape?
Erin Minnigan: It’s a transformation we’re still waiting to see. But as I mentioned, the BAR guideline did change some rules for building elevation: We shifted our mindset from “don’t elevate or slightly elevate” to “elevate up to what you need”; as elevations up to FEMA’s requirements are now possible upon design review, Charleston’s historic homes may now have better long-term resiliency.
Ziming Wang: What’s your organization’s current priority? What key changes in policy-making, advocacy, resilience planning or building retrofitting do you expect in the near future?
Erin Minnigan: I feel that flood policy-making is now moving forward from only protection and fortification to investigating ways through which we may more comprehensively manage water. Currently, there’s a discussion in Charleston on the master plan of the Union Pier as it is going up for sale — and there have been multiple visions of “resilient design,” including using green space as water storage.
And of course, we’ll continue to see more buildings elevated. Maybe after some time, everyone will see new foundations as a nice addition.
The Preservation Society is actually involved in many projects — such as the Union Pier as I just mentioned, and the US Army Corps of Engineers’ 12-foot-tall sea wall proposal that would encircle the peninsula. We want to engage the public and make sure that these projects are designed with our unique historic environment in mind.
* This interview text has been transcribed and edited based on the interviewer’s notes. For more information, see Erin Minnigan’s presentation “A Shift in Mindset to Support Elevating Historic Buildings” at 2020 Nantucket Preservation Symposium.
[1] Charleston BAR’s current elevation guideline still encourages Category 1 (“Exceptional”) or Category 2 (“Excellent”) historic buildings to gain FEMA variances; while Category 3 and Category 4 buildings may elevate for more than 3 feet upon design review.
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