# Building permits at 442 Blackstone Dr, Marin County, CA Two permits on record here. The newest, Dec 22, 2025: Replace Mechanical Appliance. Within a quarter mile, the county has issued 13 more permits since May 1. ## At this address | Date | Type | Work | Cost | Permit | |---|---|---|---|---| | Dec 22, 2025 | Mechanical (HVAC) | Replace Mechanical Appliance; | $5,000 | [B45261](https://nearbypermits.com/marin-county/permit/B45261/) | | Jun 30, 2023 | Plumbing | Replace Plumbing Fixtures(s); | $1,500 | [B34529](https://nearbypermits.com/marin-county/permit/B34529/) | ## Within ¼ mi since May 1, 2026 13 permits in the circle. From our copy of the county's data (last 24 months). ### Next door (under 250 ft), 1 permits | Date | Address | Distance | Type | Work | Cost | Permit | |---|---|---|---|---|---|---| | Aug 25, 2026 | [15 Unionstone Dr](https://nearbypermits.com/marin-county/address/15-unionstone-dr/) | 180 ft NE | Mechanical (HVAC) | Replace Mechanical Appliance; | $8,617 | [B48059](https://nearbypermits.com/marin-county/permit/B48059/) | ### This block (250 to 1,000 ft), 8 permits | Date | Address | Distance | Type | Work | Cost | Permit | |---|---|---|---|---|---|---| | Oct 2, 2026 | [2797 Las Gallinas Ave](https://nearbypermits.com/marin-county/address/2797-las-gallinas-ave/) | 550 ft NE | Electrical | New Circuits / Outlets, Service Upgrade; | $9,823 | [B48627](https://nearbypermits.com/marin-county/permit/B48627/) | | Sep 28, 2026 | [5 Unionstone Ln](https://nearbypermits.com/marin-county/address/5-unionstone-ln/) | 720 ft N | Roofing | ReRoofing; | $40,000 | [B48513](https://nearbypermits.com/marin-county/permit/B48513/) | | Sep 23, 2026 | [2661 Las Gallinas Ave](https://nearbypermits.com/marin-county/address/2661-las-gallinas-ave/) | 490 ft SE | Plumbing | Replace Plumbing Fixtures(s); | $3,200 | [B48461](https://nearbypermits.com/marin-county/permit/B48461/) | | Sep 2, 2026 | [3 Sandstone Ct](https://nearbypermits.com/marin-county/address/3-sandstone-ct/) | 960 ft E | Other | | $188,536 | [182490](https://nearbypermits.com/marin-county/permit/182490/) | | Jul 27, 2026 | [10 Sandstone Ct](https://nearbypermits.com/marin-county/address/10-sandstone-ct/) | 760 ft E | Electrical | Service Upgrade; | $4,500 | [B47634](https://nearbypermits.com/marin-county/permit/B47634/) | | Jun 18, 2026 | [3 Unionstone Ln](https://nearbypermits.com/marin-county/address/3-unionstone-ln/) | 830 ft N | Mechanical (HVAC) | Replace Mechanical Appliance; | $19,000 | [B47215](https://nearbypermits.com/marin-county/permit/B47215/) | | Jun 17, 2026 | [9 Valleystone Dr](https://nearbypermits.com/marin-county/address/9-valleystone-dr/) | 800 ft W | Plumbing | Replace Plumbing Fixtures(s); | $17,000 | [B47202](https://nearbypermits.com/marin-county/permit/B47202/) | | May 18, 2026 | [45 Rhinestone Ter](https://nearbypermits.com/marin-county/address/45-rhinestone-ter/) | 850 ft N | Plumbing | Replace Plumbing Fixtures(s); | $2,500 | [B46842](https://nearbypermits.com/marin-county/permit/B46842/) | ### Farther (1,000 ft to ¼ mi), 4 permits | Date | Address | Distance | Type | Work | Cost | Permit | |---|---|---|---|---|---|---| | Aug 18, 2026 | [345 Ironstone Ct](https://nearbypermits.com/marin-county/address/345-ironstone-ct/) | 0.23 mi E | Electrical | Service Upgrade, EV Charging Station; | $6,886 | [B47957](https://nearbypermits.com/marin-county/permit/B47957/) | | Jun 10, 2026 | [2826 Las Gallinas Ave](https://nearbypermits.com/marin-county/address/2826-las-gallinas-ave/) | 0.21 mi NE | Other | | $60,000 | [B47098](https://nearbypermits.com/marin-county/permit/B47098/) | | Jun 10, 2026 | [355 Ironstone Ct](https://nearbypermits.com/marin-county/address/355-ironstone-ct/) | 0.21 mi E | Plumbing | Replace Plumbing Fixtures(s); | $20,610 | [B47090](https://nearbypermits.com/marin-county/permit/B47090/) | | May 29, 2026 | [345 Ironstone Ct](https://nearbypermits.com/marin-county/address/345-ironstone-ct/) | 0.23 mi E | Electrical | Service Upgrade, EV Charging Station; | $4,800 | [B46962](https://nearbypermits.com/marin-county/permit/B46962/) | ## Zoning requests nearby We don't list zoning cases for Marin County yet. Look them up on the county's Planning Commission page: https://www.marincounty.gov/departments/cda/planning/boards-commissions-and-public-hearings/about-planning-commission ## More on this street Other addresses on Blackstone Dr with permits, nearest house number first: - [429 Blackstone Dr](https://nearbypermits.com/marin-county/address/429-blackstone-dr/): newest permit Apr 14, 2025 - [428 Blackstone Dr](https://nearbypermits.com/marin-county/address/428-blackstone-dr/): newest permit Apr 7, 2026 - [419 Blackstone Dr](https://nearbypermits.com/marin-county/address/419-blackstone-dr/): newest permit Jun 10, 2025 - [417 Blackstone Dr](https://nearbypermits.com/marin-county/address/417-blackstone-dr/): newest permit Feb 26, 2026 - [414 Blackstone Dr](https://nearbypermits.com/marin-county/address/414-blackstone-dr/): newest permit Jun 17, 2026 - [479 Blackstone Dr](https://nearbypermits.com/marin-county/address/479-blackstone-dr/): newest permit Oct 7, 2024 - [499 Blackstone Dr](https://nearbypermits.com/marin-county/address/499-blackstone-dr/): newest permit Nov 19, 2025 - [358 Blackstone Dr](https://nearbypermits.com/marin-county/address/358-blackstone-dr/): newest permit Dec 8, 2025 - [530 Blackstone Dr](https://nearbypermits.com/marin-county/address/530-blackstone-dr/): newest permit Jan 28, 2026 - [316 Blackstone Dr](https://nearbypermits.com/marin-county/address/316-blackstone-dr/): newest permit Jul 16, 2026 --- Source: Marin County Community Development Agency permit data (https://data.marincounty.gov/d/mkbn-caye), County of Marin, CA, ODbL 1.0 (https://opendatacommons.org/licenses/odbl/1-0/). Checked 2026-10-17 21:43 UTC. Nearby Permits, https://nearbypermits.com. JSON API and MCP server: https://nearbypermits.com/developers/ Contains information from Building Permit (County of Marin, CA), which is made available here under the Open Database License (ODbL). Database: https://data.marincounty.gov/d/mkbn-caye License: https://opendatacommons.org/licenses/odbl/1-0/ Map, both permits at this address and 13 nearby: https://nearbypermits.com/marin-county/address/442-blackstone-dr/