Methodology
How we calculate closure rates and which permits we count for Boston.
What is a closure rate?
When a contractor pulls a building permit in Boston, an inspector needs to verify the work was completed correctly before the permit can be closed. A closure rate measures the percentage of an applicant’s permits that have been properly closed:
The 365-day eligibility rule
A contractor who pulled a permit last month hasn’t had time to complete the work yet. To avoid penalizing recent activity, we only count permits issued more than 365 days ago when calculating closure rates.
Permits issued within the last year still appear in the data but are dimmed in the table and not factored into the rate.
Which permits are included?
Not all Boston permits represent inspectable construction work. We include only permits where closure is a meaningful signal of contractor accountability:
| Permit Type | Work Types Included |
|---|---|
| Electrical Permit | All |
| Plumbing Permit | All |
| Gas Permit | All |
| Erect / New Construction | All |
| Foundation Permit | All |
| Electrical Fire Alarms | All |
| Electrical Low Voltage | All |
| Long Form / Alteration Permit (including amendments) | All except: signs, annual maintenance, awnings, subdivisions, and data-migration artifacts |
| Short Form Bldg Permit | Interior renovations, interior/exterior work, exterior renovations, interior demolition, erect, change of occupancy, fast track, additions, sprinklers, fire alarm, solar panels |
The MAINT (Annual Maintenance) work type is excluded across all permit types — these are recurring inspections, not one-time construction work.
What is excluded?
We exclude permits where low closure rates are systemic rather than specific to any individual:
Entire permit types
Certificate of Occupancy, Use of Premises, and Electrical Temporary Service are administrative or temporary permits — not inspectable construction work.
Short Form work types
The Short Form permit covers a wide range of work. Many types have uniformly low closure rates for structural reasons, not contractor negligence:
| Work Type | Reason |
|---|---|
| Roofing, Siding, Driveways | Industry-wide ~10-16% closure. Contractors complete the work but almost never close the permit. |
| Insulation | Dominated by Mass Save weatherization programs (~13% closure). Systemically unclosed. |
| Demolition / Removal | Building is demolished. Nobody returns to close the permit. |
| Boring / Test Pits | Geotechnical surveys — drill, sample, leave. Not construction. |
| Tents, Events, Canopies | Temporary by nature — special events, holiday vendors, temporary structures. |
| Other / COB | Overwhelmingly tents, stages, and event structures under Short Form. |
| Fencing | Low closure, excluded from Short Form. |
Long Form work types
| Work Type | Reason |
|---|---|
| Signs | Sign companies, not construction contractors (7% closure across 5,500+ permits). |
| Annual Maintenance | Recurring inspections, not construction work. |
| Data Migration Artifacts | Legacy system conversion records. Not real permits. |
| Awnings | Almost never closed (~6% closure). |
| Subdivision / Lot Combining | Land use, not construction. |
Deduplication
The source dataset stores one row per permit × parcel combination. When a single permit covers a building with multiple tax parcels — such as a condo complex with 84 units — that permit appears as 84 rows in the raw data. Without correction, one permit could count 84 times toward an applicant’s closure rate.
We deduplicate on permit number during each nightly refresh, keeping one row per unique permit. This reduces the dataset from ~715,000 raw rows to ~642,000 unique permits.
Status classification
Boston permits have four statuses. We use two for closure rate calculations:
| Status | Classification |
|---|---|
| Open | Counted as open — work not yet signed off |
| Closed | Counted as closed — inspector verified completion |
| Issued | Excluded — permit just issued, closure not yet expected |
| Stop Work | Excluded — work halted, closure not applicable |
Leaderboard criteria
The leaderboard applies two additional filters:
- Minimum 20 rated permits — avoids surfacing statistically insignificant data.
- Active in the last 3 years — prevents the list from being populated by defunct companies.
The leaderboard can be filtered by permit type (e.g., Electrical, Plumbing). When filtered, both thresholds apply only to permits of the selected type.
Median comparison
On applicant detail pages, each closure rate is compared to the median closure rate across all leaderboard-eligible applicants in the same category. This gives context — a 50% closure rate means something different in a category where the median is 40% versus one where it’s 80%.
Medians are calculated from the same pool of applicants who meet the 20-permit minimum threshold.
Data source
All data comes from the Approved Building Permits dataset on Analyze Boston. The dataset is refreshed nightly.
Limitations
This site shows permit closure data. It does not evaluate the quality of anyone’s work. There are legitimate reasons a permit may remain open:
- Client non-cooperation — the property owner may fail to schedule the final inspection or grant access.
- Administrative backlog — work may be inspected and approved but not yet updated in the system.
- Project delays — financing, design changes, supply chain issues, or other factors outside the applicant’s control.
- Multi-phase projects — large commercial projects may legitimately take years to complete.
- Permit holder vs. contractor — the applicant may be a GC, architect, or owner — not necessarily the person scheduling the inspection.
If you believe there are inaccuracies in the underlying permit data, contact the Boston Inspectional Services Department at [email protected].