Widening Interior Doorways to 36 Inches in Pinellas Pre-1990s Homes: Framing, Headers, and When It Gets Expensive

Most of the interior doors in a St. Pete home built before 1990 measure out at a 30-inch or 32-inch rough opening, which gives you a clear passage of maybe 28 or 29 inches after the jamb and door slab eat their space. A wheelchair needs 32 inches minimum to pass through and 36 inches to pass through comfortably. A walker user needs 34 to 36 inches. If the hallway is already in the 60-inch range for a turn, widening the door is the single next move that keeps the house accessible without ripping the floor plan apart.

Core answer: widening a 30-inch interior doorway to 36 inches in a Pinellas pre-1990s home costs $700 to $2,500 per opening when the wall is non-load-bearing and sits mid-span, and $2,500 to $6,000 or more when the opening is in a load-bearing wall, a structural joint, or carries a pocket door, electrical, or plumbing in the headers. The physical work is framing and drywall. The real variable is what the wall is doing structurally and what else lives inside it.

Load-Bearing vs Non-Load-Bearing: The Question That Sets the Price

Load-bearing walls carry the roof or the floor above them down to the foundation. Non-load-bearing walls just divide space. In most Pinellas 1950s-to-1980s single-story slab-on-grade houses, the exterior walls, the central spine wall running the long axis of the house, and any wall under a floor-system beam are load-bearing. Everything else usually is not.

Three field tests the framer runs before quoting:

1. Pull the attic hatch and look at how the ceiling joists run. If they run perpendicular to a wall and bear directly on its top plate, that wall is load-bearing.
2. Check whether the wall sits under a header, a glulam, or a steel beam in the attic. Beams land on load-bearing walls, not partitions.
3. Measure the wall thickness. Interior partitions in pre-1990s Pinellas framing are often 3.5 inches of 2x4 wall. Thickened walls carrying beam loads sometimes measure 4.5 inches or more.

If the framer calls it load-bearing, the new header has to carry the load across the wider opening. That drives the cost. If it is non-load-bearing, the header is a code-minimum spacer and the labor compresses to half a day of framing plus drywall and trim.

Header Sizing for a 36-Inch Doorway

A header is the horizontal structural member above the door opening that transfers the load above the opening out to the king studs on either side. On a non-load-bearing wall, Florida Building Code Residential allows a flat 2x4 or a pair of 2x6s. On a load-bearing wall carrying a single story above, a 36-inch rough opening typically takes a pair of 2x10s or 2x12s with a half-inch plywood spacer, nailed per FBC-R Section R602.7. On a load-bearing wall carrying a floor system above (two-story house or a floor over the garage), the header may size up to an LVL (laminated veneer lumber) at 1.75 inches by 9.25 or 11.25 inches, specified by span tables or by a Florida-licensed structural engineer when the span and load exceed the prescriptive tables.

Jeremy Wharton on how we handle this in the field, from the owner interview series: "Widening doorways located midway down a wall is very easy, just a little bit of framing and drywall, creating a new header. If the door is at a structural joint where multiple walls come together, or if it's a pocket door with electricity or switches in the way, it can become a little more of a nightmare."

The flat framing math is the floor of the project. The ceiling comes from everything in the wall that is not framing.

Pinellas Pre-1990s Wall Types That Complicate the Retrofit

Three wall types we see across St. Pete, Shore Acres, Snell Isle, Old Northeast, and the beach communities, each with its own gotcha:

• Standard 2x4 wood frame with gypsum drywall. The clean case. Most interior partitions in Pinellas tract housing from the 1960s and 1970s look like this. Widening a doorway here is framing, drywall patch, jamb, slab, and casing.
• Plaster over wood lath. Common in Old Northeast and some older Pass-a-Grille properties. Plaster will crack across the whole wall if the framer tries to patch it with drywall. We skim the entire wall or replace it when the budget allows, which adds a day or two to the schedule.
• CMU block interior partition. Less common but it shows up in some mid-century Pinellas builds, especially around utility walls. Cutting a block wall for a doorway is a saw-and-rebar job, not a framing job. The header becomes a precast lintel or a steel angle, and the cost roughly doubles over a wood-frame equivalent.

When the client is planning for aging in place and the home is Old Northeast plaster or has CMU partition, we talk through the finish-level decisions early. Plaster patch, full-wall skim, or wall replacement are three different budgets.

The Nightmare Scenarios

Four situations drive the cost from the $700 to $2,500 range into the $2,500 to $6,000+ range:

1. Pocket door being converted to a swinging door, or vice versa. The existing cavity for the pocket door is wider and taller than a standard header stud bay, so the new rough opening has to be re-framed from scratch.
2. Electrical home runs or switch legs inside the header. Common when the door is next to a light switch. Those circuits have to be rerouted by a licensed electrician before framing can proceed.
3. A structural joint, where a load-bearing wall meets a perpendicular partition or a corner, often with a double or triple stud carrying beam loads. These require a structural engineer's stamp for the new header.
4. Plumbing vent stacks or water lines routed through the wall above the door. Rare but it shows up in Florida ranch houses where a bathroom shares the back of the hallway wall. Plumbing reroute adds a licensed plumber, a permit scope-up, and a slab cut if the drain line is in play.

Permit Path and Timeline

Any doorway widening that modifies structure requires a City of St. Petersburg building permit (homes in unincorporated Pinellas go through the County). Current permit turnaround runs about three to five weeks. Non-structural work (replacing a door slab without changing the opening) does not require a permit. The permit application lists the header size, the span, and whether the wall is load-bearing. For load-bearing openings in multi-story construction, a Florida-licensed structural engineer's stamp is typically required.

A clean three-doorway aging-in-place package (one bathroom, one bedroom, one hallway) on a single-story Pinellas home typically runs seven to ten calendar days of on-site work after permit issue, with framing, drywall, trim, paint, and fixture install all sequenced in that window.

Revolution Contractors runs a St. Pete general contracting shop with 20+ W-2 carpenters in-house and over a decade of remodeling across Pinellas County. The company holds two Florida contractor licenses, CRC1331628 Residential Contractor (Jeremy Wharton) and CGC1522463 Certified General Contractor (Brent Patterson), which cover residential and general construction scope. We work on an open-book Time and Materials model, which means every line item on the budget is visible to the owner each week.

Doorway widening sits inside our broader aging-in-place services and our general home remodel scope. For the full set of accessibility modifications we install most often, including grab bars, roll-in showers, and ramps, see accessible home renovations in St. Pete and the companion aging-in-place modifications deep-dive. For an Old Northeast specific retrofit sequence, see our write-up on 1960s Old NE bathroom aging retrofits.

Frequently Asked Questions

Ready to Walk Your Doorway Scope with a Pinellas Crew?

If you are thinking about widening a doorway or two during a planned remodel, the smart move is to measure the hallway and the hinge-side swing clearances before you commit to a layout. We walk through the house once, mark the doors that need to grow, and give you a line-item breakdown of which ones are framing-day easy and which ones are headed into header-and-engineer territory. Most people are surprised at how little the easy ones cost. The ones that get expensive are expensive for reasons we can see on the walkthrough, not reasons that surface halfway through the job.

Visit our Aging in Place services page to start a scope conversation.