Top 100 Contractors in NAICS 54135: Building Inspection Services, Aug 2025–Jul 2026
Parent companies by net contract obligations Aug 1, 2025 – Jul 31, 2026 Code page on GovTribe
The latest 12 months. See the newest fiscal year's list: Top Contractors in NAICS 54135: Building Inspection Services, FY2025.
The top 10 won 55% of NAICS 54135 contract dollars from August 2025 through July 2026
Ranking facts
- Contract obligations
- $123,018,783 Net of deobligations, by contracts coded NAICS 54135 or a code under it
- Contractors
- 230 Parent companies with an obligation
- Largest contractor
- OST Inc. $22.3 million, 11.5% of obligations
- Data as of
Contract actions from FPDS (SAM.gov). How the rankings work · Download all 100 rows as CSV · Free to reuse with credit to GovTribe (CC BY 4.0)
Full ranking
| Rank | Contractor | Net obligations | Share | Trend |
|---|---|---|---|---|
| 1 |
OST Inc.
Top agencies
|
$22,290,493 | ||
| 2 |
T2S, LLC
Top agencies
|
$21,883,379 | ||
| 3 | $13,198,775 | |||
| 4 |
E.f. Kearney, Limited
Top agencies
|
$13,104,470 | ||
| 5 |
Analex Corporation
Top agencies
|
$8,526,000 | ||
| 6 |
RER Solutions, Inc.
Top agencies
|
$7,293,845 | ||
| 7 | $7,149,554 | |||
| 8 | $5,177,379 | |||
| 9 | $4,678,680 | |||
| 10 | $3,809,419 | |||
| 11 | $3,522,849 | |||
| 12 |
BAE Systems
Top agencies
|
$3,515,374 | ||
| 13 | $3,203,439 | |||
| 14 | $3,068,936 | |||
| 15 |
Buchanan & Edwards Inc.
Top agencies
|
$2,340,011 | ||
| 16 |
Szpm-Alpha Mpjv
Top agencies
|
$2,123,474 | ||
| 17 | $1,500,249 | |||
| 18 |
Knowesis, Inc.
Top agencies
|
$1,358,291 | ||
| 19 | $909,641 | |||
| 20 | $854,112 | |||
| 21 | $759,265 | |||
| 22 |
Parsons Corporation
Top agencies
|
$721,228 | ||
| 23 |
Barbaricum LLC
Top agencies
|
$590,500 | ||
| 24 | $454,872 | |||
| 25 | $449,409 | |||
| 26 |
Hurtvet Subcontracting LLC
Top agencies
|
$436,982 | ||
| 27 | $409,364 | |||
| 28 |
Project Solutions, Inc.
Top agencies
|
$401,436 | ||
| 29 |
Dayton Group Inc
Top agencies
|
$400,750 | ||
| 30 | $388,064 | |||
| 31 |
Southco Services LLC
Top agencies
|
$376,530 | ||
| 32 | $334,441 | |||
| 33 | $288,121 | |||
| 34 |
Lalini Enterprises LLC
Top agencies
|
$284,094 | ||
| 35 |
Optimum Low Voltage LLC
|
$280,830 | ||
| 36 | $268,300 | |||
| 37 |
Territory Horticulture
Top agencies
|
$259,293 | ||
| 38 | $233,245 | |||
| 39 | $232,916 | |||
| 40 | $215,773 | |||
| 41 |
WRG Fire Training Simulation Systems Inc.
Top agencies
|
$214,198 | ||
| 42 | $212,206 | |||
| 43 | $209,000 | |||
| 44 |
RSA Engineering, Inc.
Top agencies
|
$206,930 | ||
| 45 |
Blackrock Institutional Trust Company National Association
|
$198,494 | ||
| 46 | $190,650 | |||
| 47 |
SDV Services, Inc.
Top agencies
|
$190,260 | ||
| 48 | $179,009 | |||
| 49 | $176,718 | |||
| 50 | $166,205 | |||
| 51 | $162,842 | |||
| 52 | $156,404 | |||
| 53 | $155,890 | |||
| 54 | $152,731 | |||
| 55 | $151,082 | |||
| 56 | $149,363 | |||
| 57 |
Tekton CC, LLC
Top agencies
|
$148,067 | ||
| 58 | $144,785 | |||
| 59 | $143,785 | |||
| 60 |
BBL Bahnbau Lüneburg GMBH
Top agencies
|
$143,247 | ||
| 61 |
DB Netz Aktiengesellschaft
Top agencies
|
$142,212 | ||
| 62 | $140,494 | |||
| 63 |
Heat Group Ltd
Top agencies
|
$136,500 | ||
| 64 |
Access North Ltd
Top agencies
|
$131,888 | ||
| 65 | $131,081 | |||
| 66 |
EDL Construction Inc.
Top agencies
|
$125,519 | ||
| 67 |
Catalyst Diving, Inc.
Top agencies
|
$125,000 | ||
| 68 |
J3 Enterprise LLC
Top agencies
|
$124,279 | ||
| 69 | $123,466 | |||
| 70 |
Caldaia Controls LLC
Top agencies
|
$117,740 | ||
| 71 |
All In Express Inc.
Top agencies
|
$116,999 | ||
| 72 | $111,566 | |||
| 73 | $110,625 | |||
| 74 |
J. Groenewald Properties CC
Top agencies
|
$101,882 | ||
| 75 |
Enviros LLC
Top agencies
|
$96,528 | ||
| 76 |
NV5 Global, Inc.
Top agencies
|
$96,503 | ||
| 77 | $93,475 | |||
| 78 |
Kulani Inc.
Top agencies
|
$92,226 | ||
| 79 | $90,958 | |||
| 80 |
Ati, Inc.
Top agencies
|
$90,228 | ||
| 81 | $89,755 | |||
| 82 | $89,750 | |||
| 83 | $85,950 | |||
| 84 | $84,856 | |||
| 85 | $82,601 | |||
| 86 | $73,000 | |||
| 87 |
PBG Ventures LLC
Top agencies
|
$71,524 | ||
| 88 | $65,207 | |||
| 89 | $64,000 | |||
| 90 | $62,800 | |||
| 91 | $62,721 | |||
| 92 | $61,200 | |||
| 93 | $58,304 | |||
| 94 | $56,450 | |||
| 95 |
Construcciones Vinpar S.A.S.
Top agencies
|
$55,420 | ||
| 96 | $55,365 | |||
| 97 | $54,867 | |||
| 98 |
Winergy LLC
Top agencies
|
$54,526 | ||
| 99 | $53,672 | |||
| 100 |
Golden Gate Federal LLC
Top agencies
|
$52,400 |
Show 75 more
100 of 230 contractors listed here. See the rest on GovTribe.
Rankings for the codes under NAICS 54135
| Code | Net obligations | Largest contractor |
|---|---|---|
| 541350 Building Inspection Services | $123,018,783 | OST Inc. |
How this ranking works
- Source: every contract action FPDS records (as published on SAM.gov) in the period, as GovTribe received it.
- Amounts are net obligations: what was obligated, less what was deobligated. Shares are of $194 million obligated before deobligations, so they never pass 100%.
- Parent companies: each action counts under the ultimate parent its award record names, or under the awardee when it names none, so no dollar counts twice. An awardee whose own actions mostly name no parent, and that no other company's actions name as their parent, rolls up its SAM.gov registration's chain of parent companies: it counts under the first company there that other companies' actions name as their parent, or under the parent most of a company's own actions name, whichever comes first; with neither, under the highest company in the chain with federal contracts of its own. Joint ventures stay companies of their own. Parents of the same name (Inc., LLC and the like aside) count as one company, since FPDS records a company's parent under more than one UEI over time. GovTribe corrects a few parents and names by hand; see the corrections.
- Period: the trailing 12 months end with the last month that ended at least 90 days ago, because the Department of Defense reports its contract actions to FPDS about 90 days late. The list is rebuilt each night.
- Rank changes compare with Aug 2024–Jul 2025. "New" marks a company outside that period's top 500, and "Returned" one of those that was on an earlier fiscal year's list.
- Rank lines show each company's rank on every fiscal year's list since FY2021, #1 at the top, on a scale that gives the top of the list more room. A dashed stretch spans years it wasn't on the list.
- Placeholder recipients FPDS uses when it names no company ("Miscellaneous Foreign Contractors" and the like) aren't ranked.
Quick answers
Who were the top 10 NAICS 54135 contractors in Aug 2025–Jul 2026?
1. OST Inc. ($22.3M), 2. T2S, LLC ($21.9M), 3. National Opinion Research Center ($13.2M), 4. E.f. Kearney, Limited ($13.1M), 5. Analex Corporation ($8.53M), 6. RER Solutions, Inc. ($7.29M), 7. Tribal One Technology, LLC ($7.15M), 8. Systems Planning and Analysis, Inc. ($5.18M), 9. Institute for Building Technology and Safety ($4.68M), 10. Data Computer Corporation of America ($3.81M).
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