# Building permits at 420 S 42nd St, Boulder, CO

Four permits on record here. The newest, Mar 4, 2025: Replacement furnace 97% AFUE 70,000 BTU. Boulder publishes permits without map coordinates, so this address has no map and no quarter-mile list.

## At this address

| Date | Type | Work | Cost | Permit |
|---|---|---|---|---|
| Mar 4, 2025 | Mechanical (HVAC) | Replacement furnace 97% AFUE 70,000 BTU. Replacement air conditioner 15 SEER2 2.5 tons. Replacement water heater 50 gallon 0.63 UEF. | $15,482 | [MEC2025-00319](https://nearbypermits.com/boulder/permit/MEC2025-00319/) |
| Aug 15, 2012 | Electrical | Replacement residential electrical service, 200 amps | $3,819 | [PMT2012-03967-ELE](https://nearbypermits.com/boulder/permit/PMT2012-03967-ELE/) |
| Sep 17, 2010 | Roofing | Total tear off and reroof of existing single family dwelling. Material not identified, 19.33 squares, 4/12 pitch as indicated on permit application. | $5,569 | [PMT2010-04043-RFG](https://nearbypermits.com/boulder/permit/PMT2010-04043-RFG/) |
| Jun 22, 2005 | Mechanical (HVAC) | Replacement Forced Air Furnace, New Comfort Cooling | $4,582 | [PMT2005-20146-MEC](https://nearbypermits.com/boulder/permit/PMT2005-20146-MEC/) |

## Zoning requests nearby

We don't list zoning cases for Boulder yet. Look them up on the city's Board of Zoning Adjustment page: https://bouldercolorado.gov/government/board-commission/board-zoning-adjustment

## More on this street

Other addresses on S 42nd St with permits, nearest house number first:

- [425 S 42nd St](https://nearbypermits.com/boulder/address/425-s-42nd-st/): newest permit Oct 24, 2025
- [430 S 42nd St](https://nearbypermits.com/boulder/address/430-s-42nd-st/): newest permit May 22, 2026
- [375 S 42nd St](https://nearbypermits.com/boulder/address/375-s-42nd-st/): newest permit May 15, 2026
- [365 S 42nd St](https://nearbypermits.com/boulder/address/365-s-42nd-st/): newest permit Dec 16, 2025
- [360 S 42nd St](https://nearbypermits.com/boulder/address/360-s-42nd-st/): newest permit Jun 2, 2026
- [345 S 42nd St](https://nearbypermits.com/boulder/address/345-s-42nd-st/): newest permit May 8, 2026
- [520 S 42nd St](https://nearbypermits.com/boulder/address/520-s-42nd-st/): newest permit May 14, 2026
- [530 S 42nd St](https://nearbypermits.com/boulder/address/530-s-42nd-st/): newest permit Mar 17, 2026
- [540 S 42nd St](https://nearbypermits.com/boulder/address/540-s-42nd-st/): newest permit Sep 4, 2026
- [545 S 42nd St](https://nearbypermits.com/boulder/address/545-s-42nd-st/): newest permit Sep 1, 2026

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Source: Boulder Planning and Development Services permit data (https://www.arcgis.com/home/item.html?id=e3ff6248e4a547bcba31025d2c5c9fee). Checked 2026-10-15 07:32 UTC. Nearby Permits, https://nearbypermits.com. JSON API and MCP server: https://nearbypermits.com/developers/

All 4 permits at this address: https://nearbypermits.com/boulder/address/420-s-42nd-st/