What we changed, what it cost, how long it took.

What changed

• —Enclosed rear porch brought into the heated envelope on a new foundation
• —Sink kept on the exterior wall; peninsula instead of an island
• —Cloth-sheathed wiring replaced throughout the opened walls
• —Original heart pine floor lifted, patched into the new area and refinished as one

The constraint

The porch had been enclosed in the 1970s on piers that were never meant to carry a room. Underpinning it properly was a third of the added footprint's cost and none of it's visible.

Matching new floor into hundred-year-old heart pine is the hardest thing on this list and the thing nobody asks about in advance.

What changed

• —Load-bearing wall removed, flush beam let into the ceiling
• —Kitchen turned ninety degrees to face the new opening
• —Ceiling vaulted where the stick framing allowed it
• —Panel upgraded from 100 to 200 amp

The constraint

The beam had to land on a point load that ran to the crawlspace, which meant a new footing poured under an existing house. Two days of work you can't see and can't skip.

Post-war ranches open up more cheaply than almost anything else in Charlotte. The ceiling height, not the structure, is what limits them.

What changed

• —Joists cut and reframed to drop the shower floor flush with the room
• —Bonded sheet membrane taken up the walls and across the whole floor
• —Heated floor mat on its own circuit
• —Cast-iron waste stack replaced where it was opened

The constraint

An old leak had been quietly wetting one joist end for years. Sistering it added a week and a little over $2,000, and it was found on day three rather than after the tile went down.

Curbless is the single best money you can spend if you intend to stay in the house. It is also the one most likely to be quoted as a tiling job by somebody who hasn't looked underneath.

What changed

• —Everything replaced, every fixture in the same position
• —Tiled shower with a proper membrane in place of an acrylic surround
• —Vanity widened into six inches of dead corner nobody had used
• —Extractor ducted outside rather than into the roof space

The constraint

None worth the name, which is the point of including it. Newer houses with fixtures staying put are the most predictable work we do, and they land near the bottom of the range.

About one in five bathrooms we're asked to quote doesn't need the layout changed at all. Saying so costs us money and is still the right answer.

What changed

• —Electrical, plumbing and HVAC replaced end to end
• —Kitchen and two bathrooms rebuilt
• —Rear of the plan reworked; front rooms and trim left exactly as found
• —Insulation and air sealing throughout the exterior envelope

The constraint

The owners moved out for five months. Phasing it to stay in would have added about eleven weeks and roughly eight per cent, and we told them so before they asked.

On a whole-home the systems are half the budget before anything looks different. Homeowners consistently underestimate this and it's the main reason whole-home budgets break.

What changed

• —310 sq ft added on a new crawlspace foundation
• —Roof tied into the existing ridge with a valley rather than a step
• —Second HVAC zone added; the original system was already at capacity
• —Existing rear bedroom absorbed into a dressing room and en suite

The constraint

The rear setback, not the budget, decided the size. Three feet more would have needed a variance and about seven months of somebody else's calendar.

Every addition is a roof problem wearing a floor plan. Get the roof junction right on paper and the rest is ordinary building.