# Building permits at 120 S 31st St, Boulder, CO 10 permits on record here. The newest, Sep 15: Addition of Mini-Split System. 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 | |---|---|---|---|---| | Sep 15, 2026 | Mechanical (HVAC) | Addition of Mini-Split System. Electrical to be done by Lovell Electric Solutions. PLEASE NOTE: APPLICABLE ONLY TO SYSTEMS WITH FUEL BURNING APPLIANCES: All new plastic glued vents for fuel burning appliances must undergo pressure testing. To facilitate the inspection process, please provide photogr | $4,062 | [MEC2026-01674](https://nearbypermits.com/boulder/permit/MEC2026-01674/) | | May 31, 2024 | Mechanical (HVAC) | Void for inactivity-NO INSPECTIONS in 180 DAYS Replace furnace & AC - new 60K BTU 80% furnace & 2.0 Ton 16 SEER AC [like for like] | $14,819 | [MEC2024-00722](https://nearbypermits.com/boulder/permit/MEC2024-00722/) | | Apr 15, 2024 | Mechanical (HVAC) | Permit Voided due to 180 days of inactivity/non-inspection. Replace tank water heater - new 50 gal gas water heater (40MBH/0.63UEF) [like for like] | $3,560 | [MEC2024-00467](https://nearbypermits.com/boulder/permit/MEC2024-00467/) | | May 31, 2023 | Electrical | Install a 9.200 kw grid tied, roof flush mounted solar photovoltaic system. | $24,439 | [ELE2023-00534](https://nearbypermits.com/boulder/permit/ELE2023-00534/) | | Apr 29, 2016 | Electrical | Installation of 10.07 kw rooftop, flush mounted, grid-tied, photo-voltaic solar energy system on single family dwelling. | $21,046 | [PMT2016-01710-ELE](https://nearbypermits.com/boulder/permit/PMT2016-01710-ELE/) | | May 31, 2011 | Roofing | Tear-off & reroof of SFD, 26 squares of asphalt shingles on a pitch represented as 4/12. Shingles to comply with ASTM D225 or D3462 and D3161 Class F. Overlay not allowed - see section R907.3 (specifically item 4) of 2006 IRC. | $4,981 | [PMT2011-02193-RFG](https://nearbypermits.com/boulder/permit/PMT2011-02193-RFG/) | | Mar 25, 2011 | Mechanical (HVAC) | Replacement Forced Air Furnace | $2,660 | [PMT2011-20100-MEC](https://nearbypermits.com/boulder/permit/PMT2011-20100-MEC/) | | May 24, 2005 | Mechanical (HVAC) | New Comfort Cooling | $4,673 | [PMT2005-20122-MEC](https://nearbypermits.com/boulder/permit/PMT2005-20122-MEC/) | | Jul 2, 2004 | Electrical | Underground electrical service, and upgrade service to 200 amps. Owner contractor. | $3,000 | [PMT2004-02577-ELE](https://nearbypermits.com/boulder/permit/PMT2004-02577-ELE/) | | Jun 16, 2004 | New building | 432 square foot 13' high shed in rear yard. No electrical or mechanical work this permit. | $8,247 | [PMT2004-02316](https://nearbypermits.com/boulder/permit/PMT2004-02316/) | ## 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 31st St with permits, nearest house number first: - [105 S 31st St](https://nearbypermits.com/boulder/address/105-s-31st-st/): newest permit Apr 9, 2026 - [90 S 31st St](https://nearbypermits.com/boulder/address/90-s-31st-st/): newest permit Dec 10, 2025 - [170 S 31st St](https://nearbypermits.com/boulder/address/170-s-31st-st/): newest permit Aug 4, 2026 - [70 S 31st St](https://nearbypermits.com/boulder/address/70-s-31st-st/): newest permit Jul 8, 2025 - [180 S 31st St](https://nearbypermits.com/boulder/address/180-s-31st-st/): newest permit Jun 9, 2026 - [50 S 31st St](https://nearbypermits.com/boulder/address/50-s-31st-st/): newest permit Oct 7, 2025 - [18 S 31st St](https://nearbypermits.com/boulder/address/18-s-31st-st/): newest permit Oct 7, 2025 --- Source: Boulder Planning and Development Services permit data (https://www.arcgis.com/home/item.html?id=e3ff6248e4a547bcba31025d2c5c9fee). Checked 2026-10-13 06:42 UTC. Nearby Permits, https://nearbypermits.com. JSON API and MCP server: https://nearbypermits.com/developers/ All 10 permits at this address: https://nearbypermits.com/boulder/address/120-s-31st-st/