Who Actually
Builds Housing

Shade the country by supply rate - housing units authorized per 1,000 residents, not raw count - and a diagonal appears. A dark band of permitting runs from the Mountain West down through the Carolinas and Florida. The palest states are the coastal Northeast and the industrial Midwest: large, established populations clearing remarkably few new homes. Raw counts would hide this; per capita is the lens that makes a big slow state and a small fast one comparable.

Fig. A-01 · Choropleth, 51 jurisdictions, single-hue mauve density ramp. Hover a state for its rate and unit count; the ranked table below carries every value so the reading never rests on colour alone. Illustrative stand-in figures.

All 51 jurisdictions, ranked (data table)

State	Per 1,000	Units	Multifamily	Rate
Utah	9.8	34,000	42%
Idaho	9.2	18,000	28%
South Carolina	8.6	45,000	30%
Texas	8.4	255,000	40%
Florida	8.1	185,000	38%
North Carolina	7.0	76,000	34%
Arizona	6.8	51,000	35%
Tennessee	6.6	47,000	36%
Delaware	6.4	6,500	25%
Georgia	6.2	68,000	37%
Montana	6.1	6,800	28%
Nevada	6.0	19,000	30%
Colorado	5.9	35,000	45%
South Dakota	5.6	5,100	35%
Washington	5.0	39,000	44%
North Dakota	5.0	3,900	40%
Alabama	4.8	24,000	26%
Virginia	4.7	41,000	34%
Oklahoma	4.6	18,500	28%
Nebraska	4.5	9,000	33%
Minnesota	4.4	25,000	45%
Oregon	4.3	18,000	42%
District of Columbia	4.2	2,900	90%
New Hampshire	4.1	5,800	32%
Arkansas	4.0	12,000	27%
Indiana	3.9	27,000	30%
Kansas	3.8	11,000	30%
Iowa	3.6	11,500	34%
Missouri	3.6	22,000	35%
Wisconsin	3.5	21,000	36%
Maine	3.5	4,900	25%
Kentucky	3.4	15,500	28%
New Mexico	3.3	7,000	25%
Louisiana	3.2	14,500	24%
Maryland	3.1	19,000	38%
Wyoming	3.1	1,800	22%
Vermont	3.0	1,950	30%
Mississippi	2.9	8,500	20%
California	2.8	110,000	55%
Massachusetts	2.7	19,000	55%
Ohio	2.7	32,000	34%
New Jersey	2.6	24,000	52%
Michigan	2.5	25,000	34%
Hawaii	2.4	3,400	45%
Pennsylvania	2.2	28,000	40%
Connecticut	2.1	7,600	48%
Rhode Island	2.0	2,200	40%
Alaska	1.9	1,400	30%
New York	1.9	37,000	62%
Illinois	1.8	22,000	42%
West Virginia	1.5	2,700	20%

Line the 51 jurisdictions up by how many homes each permits per resident and the shape is lopsided: a thick stack of below-average states, then a thinning above-average tail of fast builders. 31 of 51 sit under the U.S. average; the median jurisdiction (Indiana) permits about 3.9 per 1,000. The country's housing supply is decided by a small number of outliers.

• Below U.S. average
• At or above average

Fig. A-02 · Each column counts the states whose supply rate falls in that unit-wide band. Bar caps are direct-labelled with the state count. Illustrative stand-in figures.

The same 25 metros, ranked by units permitted per 1,000 residents, each bar split into single-family and multifamily (5+ units) so rank and building shape read at once. The order is the whole argument: the leaders are mid-size Sun Belt and Mountain West metros, and the biggest, costliest coastal names sink to the bottom. Rank runs opposite to price.

1. 01 Myrtle Beach, SC 14.4
2. 02 Provo-Orem, UT 11.1
3. 03 Boise City, ID 10.5
4. 04 Raleigh-Cary, NC 10.1
5. 05 Austin-Round Rock, TX 9.9
6. 06 Jacksonville, FL 9.1
7. 07 Nashville-Davidson, TN 9.0
8. 08 Charlotte-Concord, NC 8.6
9. 09 Orlando-Kissimmee, FL 8.5
10. 10 Phoenix-Mesa, AZ 8.0
11. 11 Houston-The Woodlands, TX 7.7
12. 12 Dallas-Fort Worth, TX 7.7
13. 13 Tampa-St. Petersburg, FL 7.6
14. 14 Atlanta-Sandy Springs, GA 6.7
15. 15 Denver-Aurora, CO 6.4
16. 16 Seattle-Tacoma, WA 6.0
17. 17 Minneapolis-St. Paul, MN 4.9
18. 18 Miami-Fort Lauderdale, FL 4.6
19. 19 Washington-Arlington, DC 3.3
20. 20 Boston-Cambridge, MA 2.7
21. 21 New York-Newark, NY 2.2
22. 22 Philadelphia-Camden, PA 2.2
23. 23 San Francisco-Oakland, CA 2.0
24. 24 Los Angeles-Long Beach, CA 1.7
25. 25 Chicago-Naperville, IL 1.5

Fig. A-03 · Bar length is the supply rate; the mauve share is multifamily. Full counts in the table below. Illustrative stand-in figures.

Full metro table (units, single, multifamily)

Metro	Per 1,000	Total units	Single-fam	Multifamily	Multi %
Myrtle Beach, SC	14.4	7,500	5,500	1,700	23%
Provo-Orem, UT	11.1	8,000	4,200	3,500	44%
Boise City, ID	10.5	8,500	5,000	3,000	35%
Raleigh-Cary, NC	10.1	15,000	8,500	6,000	40%
Austin-Round Rock, TX	9.9	24,000	12,000	11,000	46%
Jacksonville, FL	9.1	15,500	9,500	5,500	35%
Nashville-Davidson, TN	9.0	19,000	10,000	8,500	45%
Charlotte-Concord, NC	8.6	24,000	14,000	9,500	40%
Orlando-Kissimmee, FL	8.5	24,000	13,500	10,000	42%
Phoenix-Mesa, AZ	8.0	40,000	26,000	13,000	33%
Houston-The Woodlands, TX	7.7	58,000	40,000	16,000	28%
Dallas-Fort Worth, TX	7.7	62,000	38,000	22,000	35%
Tampa-St. Petersburg, FL	7.6	25,000	15,000	9,000	36%
Atlanta-Sandy Springs, GA	6.7	42,000	26,000	15,000	36%
Denver-Aurora, CO	6.4	19,000	9,000	9,500	50%
Seattle-Tacoma, WA	6.0	24,000	8,000	15,000	63%
Minneapolis-St. Paul, MN	4.9	18,000	7,000	10,000	56%
Miami-Fort Lauderdale, FL	4.6	28,000	7,000	20,000	71%
Washington-Arlington, DC	3.3	21,000	8,500	11,500	55%
Boston-Cambridge, MA	2.7	13,000	4,000	8,500	65%
New York-Newark, NY	2.2	42,000	9,000	31,000	74%
Philadelphia-Camden, PA	2.2	13,500	6,500	6,000	44%
San Francisco-Oakland, CA	2.0	9,000	2,200	6,500	72%
Los Angeles-Long Beach, CA	1.7	22,000	5,000	16,000	73%
Chicago-Naperville, IL	1.5	14,000	6,000	7,000	50%

Plot every metro by population and by supply rate and the dots drift down as they drift right: the largest metros - the New Yorks and Los Angeleses where housing is scarcest and dearest - sit along the floor, while the fastest permitting happens in the smaller Sun Belt boomtowns up the left side. Size is not the constraint. The places with the most people and the most demand authorize the fewest homes per resident.

• Sun Belt boomtown
• Steady
• Supply-frozen

Fig. A-04 · One mark per metro; shape and colour both encode archetype, so the groups read under colour-blindness and in greyscale. Extremes direct-labelled; hover any dot for its figures. Illustrative stand-in figures.

Now hold volume constant and ask only about shape. Each bar is one metro's permitted units normalized to 100% and split into single-family, the 2 to 4 unit "missing middle", and multifamily (5+), sorted from most detached at the top to most apartment at the bottom. Sun Belt sprawl and Texas subdivisions anchor one end; the supply-frozen coasts, where almost every new unit is an apartment, anchor the other. Two different housing economies, drawn to the same width.

Bars normalized to 100%. Small segments omit their label; the middle band is the 2 to 4 unit class.

National housing units authorized each year, stacked by building type. The recovery from the 2008 collapse was carried by multifamily nearly as much as single-family - the apartment share crested around 2022, at roughly 40% of all new units. The 2-to-4-unit "missing middle" stayed a rounding error the entire stretch, the housing type America stopped building.

• Single-family (1 unit)
• 2 to 4 units
• Multifamily (5+ units)

Fig. A-06 · Thousands of units authorized nationwide; segment heights are the three building classes. 2024 totalled 1,506k. Illustrative stand-in figures.

Read as a rate rather than a volume, the same national data tells a structural story: the multifamily share of everything permitted climbed from about 22% in 2010 to a peak near 40% in 2022, before easing to 33%. The country is not just building - it is quietly building denser, one approval at a time.

Fig. A-07 · Multifamily (5+ unit) units as a share of all units authorized nationwide each year. Single series; peak and latest year direct-labelled. Illustrative stand-in figures.

Group the metros by archetype and index each group to its own 2010 level, and the gap becomes a matter of slope. Sun Belt boomtowns roughly doubled their pace and shrugged off the 2022 rate shock; the steady middle climbed at half that grade; the supply-frozen coasts end fifteen years almost exactly where they began. Same country, three completely different responses to the same demand.

Fig. A-08 · Each panel indexes one cohort's total permits to 2010 = 100; the two grey lines repeat the other cohorts for scale. Illustrative stand-in figures.

Here is the whole argument on one axis. Each bar is a metro's distance from the national average of 4.5 units per 1,000 residents - above to the right, below to the left. The fast-permitting Sun Belt and Mountain West metros authorize about 4.5x as many homes per resident as the big coastal metros where demand and prices are highest. Where housing costs the most, the least gets built.

• Above U.S. average
• Below U.S. average

Fig. A-09 · Bars measure each metro's supply rate against the national average; length is the size of the gap, direction is its sign. Illustrative stand-in figures.

Every metro vs the U.S. average (data table)

Metro	Per 1,000	vs U.S. avg	Total units
Myrtle Beach, SC	14.4	+9.9	7,500
Provo-Orem, UT	11.1	+6.6	8,000
Boise City, ID	10.5	+6.0	8,500
Raleigh-Cary, NC	10.1	+5.6	15,000
Austin-Round Rock, TX	9.9	+5.4	24,000
Jacksonville, FL	9.1	+4.6	15,500
Nashville-Davidson, TN	9.0	+4.5	19,000
Charlotte-Concord, NC	8.6	+4.1	24,000
Orlando-Kissimmee, FL	8.5	+4.0	24,000
Phoenix-Mesa, AZ	8.0	+3.5	40,000
Houston-The Woodlands, TX	7.7	+3.2	58,000
Dallas-Fort Worth, TX	7.7	+3.2	62,000
Tampa-St. Petersburg, FL	7.6	+3.1	25,000
Atlanta-Sandy Springs, GA	6.7	+2.2	42,000
Denver-Aurora, CO	6.4	+1.9	19,000
Seattle-Tacoma, WA	6.0	+1.5	24,000
Minneapolis-St. Paul, MN	4.9	+0.4	18,000
Miami-Fort Lauderdale, FL	4.6	+0.1	28,000
Washington-Arlington, DC	3.3	-1.2	21,000
Boston-Cambridge, MA	2.7	-1.8	13,000
New York-Newark, NY	2.2	-2.3	42,000
Philadelphia-Camden, PA	2.2	-2.3	13,500
San Francisco-Oakland, CA	2.0	-2.5	9,000
Los Angeles-Long Beach, CA	1.7	-2.8	22,000
Chicago-Naperville, IL	1.5	-3.0	14,000