Contractor permit directory

Contractors observed in Maryland county permit records, grouped from public filings. Our observation is not complete: not every filing names a contractor, so a firm's real activity is almost always greater than what appears here.

All counties Anne Arundel County Baltimore County Frederick County Howard County Prince George's County

All trades Accessory Structure Deck & Patio Electrical Exterior Fire Protection Gas Interior HVAC Plumbing Pool & Spa Sign Site Solar Structural

CONSTELLATION HOME HVAC/Anne Arundel County, Frederick County, Howard County 5316 permits/to Sep 2026
ENVIRONMENTAL SYSTEMS ASSOCIATES LLC DBA CROPPMETCALFE HVAC/Anne Arundel County, Frederick County, Howard County 1676 permits/to Sep 2026
HORIZON SERVICES MD LLC HVAC/Anne Arundel County, Frederick County, Howard County 1046 permits/to Sep 2026
CONSTELLATION HOME PRODUCTS AND SERVICES LLC HVAC/Howard County 894 permits/to Oct 2024
AMERICAN RESIDENTIAL SERVICES HVAC/Anne Arundel County, Frederick County, Howard County 871 permits/to Sep 2026
DAVE'S ELECTRIC HVAC/Anne Arundel County, Frederick County, Howard County 710 permits/to Sep 2026
LEN THE PLUMBER HVAC/Anne Arundel County, Frederick County, Howard County 682 permits/to Sep 2026
F.H. FURR PLUMBING, HEATING, AIR CONDITIONING, & ELECTRICAL HVAC/Anne Arundel County, Frederick County, Howard County 667 permits/to Sep 2026
MCCREA EQUIPMENT COMPANY HVAC/Anne Arundel County, Frederick County, Howard County, Prince George's County 522 permits/to Sep 2026
ERIC SMOCK HEATING & A/C INC HVAC/Frederick County 485 permits/to Aug 2026
NRG ENERGY/ DBA/ AIRTRON HVAC/Howard County 436 permits/to Sep 2026
MICHAEL AND SON SERVICES, INC. HVAC/Anne Arundel County, Frederick County, Howard County 428 permits/to Sep 2026
MASTERS, INC DBA AIRTRON HVAC/Howard County 374 permits/to Aug 2024
UNITED AIR TEMP HVAC/Anne Arundel County, Frederick County, Howard County 245 permits/to Sep 2026
CHARLES A KLEIN & SONS, INC. HVAC/Anne Arundel County, Frederick County, Howard County, Prince George's County 224 permits/to Sep 2026
BLUE DOT SERVICES HVAC/Howard County 218 permits/to Sep 2026
BELAIR ENGINEERING & SERVICE HVAC/Anne Arundel County, Prince George's County 216 permits/to Sep 2026
AMERICAN RESIDENTIAL SERVICE HVAC/Howard County 213 permits/to Oct 2024
SOUTHERN MARYLAND HTG & AIR HVAC/Anne Arundel County 200 permits/to Sep 2026
LARRY & SONS INC HVAC/Frederick County 198 permits/to Sep 2026
B & B AIR CONDITIONING & HEATING HVAC/Howard County 194 permits/to Sep 2026
WL STATON PLUMBING HTNG & COOL HVAC/Anne Arundel County 177 permits/to Sep 2026
TRI-STATE HOME SERVICES HVAC/Frederick County, Howard County 174 permits/to Sep 2026
HARAMIS ELECTRIC HVAC/Anne Arundel County, Howard County 154 permits/to Sep 2026
Grove Heating & Cooling Inc HVAC/Anne Arundel County, Howard County 152 permits/to Sep 2026
MARYLAND ELECTRICAL SOLUTIONS HVAC/Howard County 152 permits/to Sep 2026
BELAIR ENGINEERING & SVC CO. HVAC/Anne Arundel County 149 permits/to Sep 2026
STATON HEATING, COOLING, AND PLUMBING HVAC/Anne Arundel County 148 permits/to Sep 2026
ANTHONYS ELECTRIC HVAC/Howard County 144 permits/to Sep 2026
C & C ELECTRIC HVAC/Anne Arundel County, Howard County 136 permits/to Sep 2026
RON AIR INC HVAC/Howard County 133 permits/to Aug 2026
TITAN MECHANICAL, INC. HVAC/Anne Arundel County 124 permits/to Feb 2026
CORNETT HEATING AND COOLING , LLC HVAC/Anne Arundel County 120 permits/to Sep 2026
ARS DBA BLUE DOT OF MD HVAC/Anne Arundel County 116 permits/to Sep 2026
AMERIGAS PROPANE L.P. DBA SERVICEMARK HVAC/Howard County 110 permits/to Apr 2026
WILLIAM H. METCALFE & SONS, INC HVAC/Anne Arundel County, Howard County, Prince George's County 107 permits/to Sep 2026
CHRIS WING HVAC/Frederick County, Prince George's County 104 permits/to Sep 2026
MASTERS MID ATLANTIC LLC DBA AIRTRON LLC HVAC/Anne Arundel County, Howard County 104 permits/to Aug 2026
DUKE HEINTZELMAN HVAC/Frederick County 103 permits/to Apr 2025
HUNT PLUMBING HEATING AND AIR CONDITIONING, LLC HVAC/Howard County 102 permits/to Sep 2026
WESLEY BARR HVAC/Frederick County 102 permits/to Aug 2026
Addicks Electric LLC HVAC/Frederick County, Howard County 89 permits/to May 2026
ASC HEATING AND AIRCONDITIONING INC HVAC/Howard County 76 permits/to Aug 2026
ECOMIZE USA LLC HVAC/Anne Arundel County, Frederick County, Howard County 72 permits/to Aug 2026
Tuckers Air Conditioning, Heating and Plumbing HVAC/Frederick County 72 permits/to Aug 2026
KASTNER PLUMBING & HEATING INC. HVAC/Howard County 71 permits/to Aug 2026
WALTS MECHANICAL SERVICES INC HVAC/Howard County 68 permits/to Aug 2026
COASTAL HEATING AND AIR CONDIT HVAC/Anne Arundel County 67 permits/to Sep 2026
ST JOHN PROPERTIES INC HVAC/Anne Arundel County, Baltimore County, Frederick County, Howard County 65 permits/to Sep 2026
CK ELECTRIC LLC HVAC/Frederick County, Howard County 63 permits/to Aug 2026

Source: county permit records. Updated weekly.