Home addition cost in Boulder (2026)

The typical home addition in Boulder was valued at $86,000 on its city permit (middle half: $22,000 to $260,000), across 503 home additions with city permits issued from September 2021 to September 2026.

$86,000median value on the city permit, not the price you will payMiddle half: $22,000 to $260,000503 home additions, 2021 to 2026

How the values spread

Share of home additions in Boulder by the value on the permitMedian $86,000. Under $100,000: 256 jobs (51%); $100,000 to $200,000: 88 jobs (17%); $200,000 to $300,000: 45 jobs (9%); $300,000 to $400,000: 29 jobs (6%); $400,000 to $500,000: 23 jobs (5%); $500,000 to $600,000: 21 jobs (4%); $600,000 and over: 41 jobs (8%).51%17%9%6%5%4%8%Median $86,000$0$200k$400k$600k+
Share of home additions in Boulder by the value on the permit: 503 home additions, from September 2021 to September 2026. The dashed line is the median; half of all jobs fall between $22,000 and $260,000.
The numbers behind the chart
Value on the permitJobsShare
Under $100,00025651%
$100,000 to $200,0008817%
$200,000 to $300,000459%
$300,000 to $400,000296%
$400,000 to $500,000235%
$500,000 to $600,000214%
$600,000 and over418%

Home addition contractors with the most jobs in Boulder

RankContractorJobsContact
1Melton Design Build dba Melton Construction Inc
18
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2Sobo Design & Build
18
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3Decks By Caio
15
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By ZIP code

The 5 ZIP codes with the most home additions valued on the permit (at least 20 each).

ZIP codeJobsMedianMiddle half
80304171$86,000$29,000 to $225,000
80305146$118,000$31,000 to $322,000
8030282$143,000$50,000 to $399,000
8030370$57,000$15,000 to $162,000
8030134$14,000$7,000 to $41,000

By year

YearJobsMedianMiddle half
2021 (September to December)27$45,000$18,000 to $90,000
2022111$110,000$20,000 to $310,000
202386$100,000$31,000 to $300,000
202499$80,000$30,000 to $235,000
202598$126,000$26,000 to $291,000
2026 (January to September)82$66,000$17,000 to $197,000

What the records show

  • Share of jobs in each budget range: under $100,000: 51% (256 of 503); $100,000 to $250,000: 22% (111 of 503); $250,000 to $500,000: 15% (74 of 503); over $500,000: 12% (62 of 503).
  • The median was $110,000 in 2022 (111 jobs) and $126,000 in 2025 (98 jobs), up 15%.
  • Across the ZIP codes above, the median ran from $14,000 in 80301 to $143,000 in 80302.

Every figure here is the job value written on the city permit, not the price paid. Permit values can be higher or lower than the final price, so get more than one quote. Values under $1,000 are placeholders and are left out. Median and middle half: half of the jobs were valued above the median; the middle half runs from the 25th to the 75th percentile. Source: Boulder construction permits, from September 2021 to September 2026. Data updated September 25, 2026. The same figures as data: addition.json.