Home additions and dormers in South City St. Louis
South City lots are narrow. The two-story brick homes on The Hill, in Tower Grove, in Holly Hills, and across the South Side are typically 25 to 40 feet wide, with neighbors close on both sides. Going out is rarely an option. Going up almost always is. Most South City additions happen above the second floor, in attic and third-floor space that the original builders never finished.
Why South City homeowners trust Aleto with additions and dormers
South City homes were built on city lots, not suburban lots. The narrow widths, established neighbors, and city setback rules limit horizontal expansion in nearly every case. The brick exteriors that are part of the homes’ architectural identity make horizontal additions even more challenging because matching original brick is difficult and obvious mismatches read as scars on the building. The space that exists above the second floor (attic, third floor, and dormer territory) is where most South City homes have room to grow.
A typical South City addition takes one of three forms. A full attic build-out converts the unfinished space into a primary suite or additional bedrooms with a new bath, accessed through a new staircase that fits within the existing home’s volume. A dormer addition expands an existing partially-finished third floor into more usable space, with shed dormers on the sides or rear that don’t alter the front elevation. A rear addition (less common, but possible on some lots) extends the home toward the alley, often picking up the original brick language with care to make the addition read intentionally rather than as a patch.
Aleto Construction Group has been completing additions in South City for decades, including attic build-outs in Tower Grove four-squares, third-floor primary suites on The Hill, dormer additions in Holly Hills, and sympathetic rear additions across the South Side. Working in St. Louis since 1955 means we’ve learned where city brick homes hide their structural surprises, how a code-compliant staircase fits into a hundred-year-old plan, and how to design additions that respect the City of St. Louis’ historic district guidelines where they apply.
What an addition or dormer in South City St. Louis can include
Every project is scoped to the home and the homeowner. Here are the addition types we complete most often in South City:
Full attic and third-floor build-outs
Converting unfinished attic space into a primary suite, including bedroom, walk-in closet, primary bathroom, and a new code-compliant staircase fitting within the existing home volume
Shed dormers
Wide flat-roofed dormers on the sides or rear of the home that maximize usable floor area and headroom without changing the front elevation
Gable dormers
Peaked-roof dormers used selectively where roof geometry allows, often paired with shed dormers elsewhere on the home to balance light, headroom, and street-facing detail
Rear additions where lots allow
Single or two-story additions toward the alley on lots with the depth to support them, with brick matching and detailing to read sympathetically
Garage apartment and carriage house additions
Adding finished living space above existing alley garages or building new carriage houses on lots that allow detached structures
Historic district sensitive work
Coordinating with the City of St. Louis Cultural Resources Office for additions on homes in designated historic districts, including Holly Hills, Lafayette Square, Soulard, Compton Heights, Shaw, and others
Brick matching and tuckpointing
Sourcing reclaimed or color-matched brick for additions, integrating with original brick coursing, and tuckpointing existing masonry where the addition meets the original
Period-appropriate windows and trim
Window proportions, trim profiles, and exterior details that read as part of the original home rather than as transplants from a contemporary subdivision
What additions and dormers look like in South City St. Louis
South City additions are shaped by century-old urban brick architecture on tight lots. Here are the scenarios we see most often.
Going up because you can’t go out
The fundamental South City addition reality is geometric. The lot is 30 feet wide. Two of those feet are set back on each side. The neighbors are 6 feet from the property line. There is no room to add square footage horizontally. The vertical space above the second floor is where the addition has to happen. A full attic build-out can create a primary suite with a bedroom, a walk-in closet, and a spa bathroom in space that’s currently storing Christmas decorations. Dormer additions add headroom and natural light without requiring new foundation work. We’ve completed attic conversions throughout South City and know how to fit a code-compliant staircase, full bathroom plumbing, and HVAC into the existing volume of these homes.
Working with the City of St. Louis historic district guidelines
Several South City neighborhoods are local or National Register historic districts, including Holly Hills, Compton Heights, Lafayette Square, Soulard, Shaw, and portions of The Hill. Renovations and additions that affect the exterior of homes in these districts require review through the City of St. Louis Cultural Resources Office. The review process examines proposed additions against guidelines covering visibility from the street, massing, materials, roof form, window selection, and brick treatment. The guidelines are not arbitrary; they’re part of why these neighborhoods have held their character for a century. We design with the guidelines in mind from the start, handle the full review process, and keep the project moving through approvals.
Matching brick that doesn’t exist anymore
Original South City brick was made in St. Louis, often within a few miles of the home, from clay sources that aren’t commercially available anymore. Matching that brick on a rear or side addition requires either sourcing reclaimed brick from demolished period buildings (the best option, when supply allows), commissioning custom-fired brick from specialty suppliers, or color-matching contemporary brick as closely as possible while accepting that the match won’t be perfect. The right approach depends on the size and visibility of the addition. We work with masonry suppliers who specialize in older brick matches and have completed sympathetic additions across South City.
Designing the new staircase that fits
A specifically South City addition challenge: when an attic or third-floor build-out adds livable space, code requires a permanent staircase rather than a pull-down ladder. Fitting that staircase into a hundred-year-old home with limited circulation space means either reclaiming closet space on the second floor, taking a portion of an existing bedroom, or, in some cases, adding a dormer over an exterior side stair location. The staircase design is one of the more constrained design problems in South City addition work, and getting it right early in design is essential. A staircase that doesn’t fit kills the addition before it starts.
What our clients are saying…
“I used Aleto for an attic addition, and they were great! They were always so kind and helpful. The planning process takes a bit of time, but it is definitely worth it because it allows for a very detailed budget and makes the project go faster when they are actually in the construction phase. They are always very communicative and on schedule for the most part. I recently had a piece of siding come loose from the addition. I texted Mike and he had it taken care of right away. They stand behind their work, and I will only use Aleto for any future projects.”
Aja Martin
Featured home addition project
Lindenwood Park Upgrade
A home in the Lindenwood Park neighborhood just got an elevated upgrade—literally. This second-story addition features a spacious owner’s retreat with a light-filled bedroom, a walk-in closet, and a beautifully tiled full bathroom.
Custom details include 5×5 ceramic wall tile, a 1″ hex mosaic floor with 2′ square rug insets, and warm wood-look LVP throughout. A custom staircase ties it all together with elegance and craftsmanship.
Frequently asked questions
Will our South City home support a third-floor addition structurally?
In most cases, yes, but the engineering question is more involved than in newer suburban homes. South City brick two-story relies on the exterior brick walls plus interior bearing partitions to carry loads, and the second-floor framing is often original full-dimension lumber that needs evaluation rather than assumption. A structural engineer reviews the existing framing, foundation, and load paths during design, identifies where reinforcement is required (typically sistering joists, adding a structural ridge or beam in the attic, and verifying the masonry wall capacity), and produces drawings that the city building department will permit. Nothing is committed before that review is complete.
Does our South City home need historic district approval?
It depends on the neighborhood. Several South City neighborhoods (Holly Hills, Lafayette Square, Soulard, Compton Heights, Shaw, parts of The Hill) are designated local or National Register historic districts where exterior additions require review through the City of St. Louis Cultural Resources Office. Other South City neighborhoods don’t have such requirements. The first design step is verifying the home’s exact district status and any ward-level overlay requirements, which determines the review timeline and shapes the exterior design from the beginning.
Can we add square footage at the rear of our South City home?
Sometimes. The constraint is the lot. Some South City lots have enough depth to support a single or two-story rear addition without violating setback requirements; others don’t. Where rear additions are possible, the design challenges include matching original brick (often the most difficult part), respecting the alley’s existing rhythm, and integrating new windows and roof forms with the original home. We assess lot constraints during design and identify whether rear addition is a viable path.
More home renovation services in South City St. Louis
Looking at a different scope? Explore our other services available in South City St. Louis:
Whole home renovation
Transform your entire living space — updating layouts, finishes, and systems so everything works together.
Learn more →
Bathroom renovation
Convert dated bathrooms into spa-like retreats with custom tile, modern fixtures, and intelligent layouts.
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Bathroom renovation
Convert dated bathrooms into spa-like retreats with custom tile, modern fixtures, and intelligent layouts.
Learn more →
Ready to add space to your South City home?
A home addition starts with a conversation about how your home isn’t working today and what it could become. Tell us what you’re thinking, and we’ll take it from there.