Grunau Company

What Grunau Company does

Grunau Company is a mechanical systems union contractor headquartered in Oak Creek, Wisconsin, in the greater Milwaukee area. Founded in 1920 by Paul J. Grunau as a plumbing and repair service, the company has expanded over 105 years into a full-service mechanical contractor offering design, fabrication, installation, and 24/7 service across HVAC, plumbing, electrical, process piping, refrigeration, sheet metal fabrication, underground utilities, and medical gas systems. It holds hard-to-acquire industry credentials including ASME PP Stamp, National Board R Stamp, UA Union Label, AWS Certified Welders, ASSE 6010/6040 medical gas certifications, and was the first Wisconsin mechanical contractor to employ LEED Accredited Professionals. The company uses BIM technology continuously since 1985 for 3D modeling, clash detection, prefabrication spooling, and direct download to in-house fabrication equipment in its pipe/weld and sheet metal shops.

Grunau serves commercial, industrial, and institutional customers across eight vertical segments — Healthcare (primary), Commercial and Office, Industrial and Warehouse (including breweries, food/pharma, wastewater), Education, Government, Cultural and Entertainment, Hotels and Multi-Family, and Retail — with marquee project references including Northwestern Mutual Tower (1.1 million sq ft), Aurora Medical Center Grafton, and Marquette University Law School. The company generates revenue through project-based new construction and remodel contracts supplemented by a 24/7 preventive maintenance and emergency service subscription arm, operating primarily in southeastern Wisconsin (Madison to Green Bay corridor) with project work extending across the United States through established client relationships. Go-to-market is enterprise field sales driven by direct relationships, a website RFQ funnel, and a project gallery across industry categories.

The company has been a wholly-owned subsidiary of APi Group since 2006, following four generations of Grunau family ownership. In 2023, APi Group moved Grunau Metals to LeJeune Steel and Grunau Fire Protection to Davis Ulmer Fire Protection, narrowing Grunau's scope to its core mechanical contracting operations. Current operations are led by President Sal B. Angelo, appointed in 2022, with a workforce of 251-500 employees across the Oak Creek headquarters and a Kenosha, WI satellite office opened in 2019.

Name

Grunau Company

Legal name

Grunau Company

Website

https://grunau.com

Company type

Private

Founded year

1920

Operating status

Operating

Headcount range

251–500 employees

Short description

Grunau Company is a 105-year-old union mechanical contractor in Oak Creek, Wisconsin, providing design, fabrication, installation, and 24/7 service of HVAC, plumbing, electrical, process piping, refrigeration, sheet metal, and medical gas systems for commercial, industrial, and institutional customers across southeastern Wisconsin.

Ownership category

akta.pro rank

Headquarters

HQ city

Oak Creek

HQ country

United States

HQ region

North America

Offices2 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Supply Chain, Operations, Technology or R&D, Marketing or Sales

Revenue model

1. Mechanical Systems Construction: Design, installation, and service of mechanical systems for commercial and industrial projects. Revenue is generated through project-based contracts including new construction, remodels, and service work. The company operates as a full-service mechanical systems resource.
2. 24/7 Service and Maintenance: Emergency mechanical services and preventive maintenance contracts available 24/7, 365 days per year. Includes repairs, preventive maintenance, inspections, retrofitting, retro commissioning, and mechanical equipment testing.

Pricing tiers

Go-to-market motion1 record

Distribution channels1 record

Marketing channels4 records

Core offering

Grunau Company is a mechanical systems union contractor providing design, fabrication, installation, and 24/7 service of mechanical systems for commercial, industrial, and institutional facilities. Core offerings include HVAC, plumbing, electrical, process piping, refrigeration, sheet metal fabrication, underground utilities, and medical gas systems, supported by in-house pipe/weld and sheet metal fabrication shops and BIM-enabled preconstruction engineering.

Product overview

Grunau Company is a mechanical systems union contractor offering a comprehensive portfolio of integrated mechanical contracting services for commercial, industrial, and institutional applications. The company operates as a full-service mechanical systems resource combining design, installation, and 24/7 service capabilities. The core service offerings include HVAC, Plumbing, Electrical, Process Piping, Refrigeration, Underground Utilities, Sheet Metal Fabrication, and Medical Gas systems. Supporting these core mechanical services are value-added capabilities including a Custom Pipe Fabrication and Weld Shop, Building Information Modeling (BIM), Preconstruction Services, Safety Culture programs, Lean Construction methodology, Integrated Project Delivery (IPD), and LEED Sustainability consulting. The company serves diverse industries including healthcare, education, commercial office, industrial/warehouse, retail, government, cultural/entertainment, and hotels/multi-family sectors.

Differentiator

Problem solved

Functional benefit

Products and services

• HVAC Design, fabrication, and installation of HVAC systems for commercial, industrial, and institutional applications including forced air, hot water, chilled water, steam, split systems, geothermal, computer room, process heating and cooling, refrigeration, underfloor air distribution, exhaust and ventilation, humidification and dehumidification, and dust collection.
• Plumbing Plumbing engineering and installation services including engineered plumbing systems, design-build plumbing systems, pure water systems, medical gas systems, laboratory gas systems, prefabrication, primary and secondary storm drainage systems, water mains, pipe bursting, and directional boring.
• Electrical Electrical system design and installation including temperature controls, building automation systems, electric vehicle recharging stations, lighting, electrical panels, feeders and transformers, outlets and switches, fire alarms, and Focus on Energy Wisconsin Trade Ally services.
• Refrigeration Licensed sales, service, and installation of commercial and industrial refrigeration equipment including coolers, freezers, refrigerated display cases, beverage dispensers, bar cabinets, glass frosters, vertical air curtains, ice machines, certified ABS piping, and advanced low-temperature CO2 systems.
• Underground Utilities Underground utilities contractor services for new installation, remodels, and repairs including underground piping, underground plumbing, storm drainage, sewer lines, and geothermal lines.
• Sheet Metal Fabrication In-house sheet metal duct fabrication for any shape or size including rectangular or spiral duct, kitchen exhaust, and heavy gauge work, using 10 gauge to 26 gauge materials in aluminum, stainless, galvanized, and black iron with plasma table and coil line equipment.
• Medical Gas Medical gas inspections, maintenance, service, and installations for hospitals, dental clinics, laboratories, and veterinary practices. Technicians are certified in ASSE 6010 and ASSE 6040 with expertise in NFPA 99 code requirements.
• Custom Pipe Fabrication and Weld Shop Custom pipe fabrication and weld facilities providing quality prefabricated materials with pipe sizes from 1/4 inch to 132 inches in carbon steel, stainless steel, and specialty alloy piping, with UA Union Label, AWS Certified Welders, ASME PP Stamp, and National Board R Stamp qualifications.
• Process Piping Process piping design and installation for breweries, food and pharmaceutical plants, and wastewater treatment facilities with ASME PP Stamp and National Board R Stamp certifications, certified welders per ASME Section IX, and capabilities for hydrostatic and pneumatic pressure testing.
• 24/7 Emergency Mechanical Services Round-the-clock emergency mechanical services for commercial and industrial facilities in southeastern Wisconsin covering repairs, preventive maintenance, inspections, retrofitting, retro commissioning, mechanical equipment testing, backflow prevention testing, medical gas inspections, HVAC, plumbing, water treatment, process piping, electrical, temperature controls, building automation, and underground utilities.
• Building Information Modeling (BIM) Virtual modeling and Building Information Modeling services using 3D intelligent solids for collision detection, integrated estimating, Navisworks models and clash reports, work packages, virtual mock-ups, as-built models, spool welded piping for prefabrication, and direct download to fabrication equipment.
• Preconstruction Services Professional preconstruction engineering services including design, design-build, design-assist, engineering, estimating and budgeting, master planning, computer-aided design services, BIM, systems evaluation, and Integrated Project Delivery.
• Integrated Project Delivery (IPD) Integrated Project Delivery approach combining collaboration, teamwork, and shared stakeholder responsibility, utilizing tools like Pull Planning and Last Planner with a track record of delivering quality products under budgeted costs.
• LEED Sustainability Services LEED sustainability services including indoor air quality, resource-efficient electrical and plumbing fixtures, solar, and geothermal systems, supported by LEED Accredited Professionals on staff.

Quantifiable outcome

• Grunau completed a hospital HVAC upgrade at William S Middleton Memorial Veterans Hospital with a 24-hour window, finishing the final tie-ins and exchange within 10 hours
• +3 more outcomes

Named customers9 records

Segments8 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Scale indicators4 records

Recent moves8 records

Expansion highlights5 records

Direct peers

• Limbach Holdings: Limbach Holdings (NYSE: LMB) is a publicly traded specialty mechanical contractor providing HVAC, plumbing, and electrical services for commercial and institutional customers. Its service mix, union/non-union workforce structure, and project-based revenue model directly parallel Grunau's full-service mechanical contracting business.
• Southland Industries: Southland Industries is a large private mechanical contractor providing HVAC, plumbing, process piping, and building automation services for commercial and industrial customers. Its self-perform MEP model, in-house fabrication, and regional service-center footprint make it directly comparable to Grunau's operating profile.
• U.S. Engineering Company Holdings: U.S. Engineering Company Holdings is a Midwest-based mechanical contractor delivering HVAC, plumbing, process piping, and prefabrication services for commercial, industrial, and institutional customers. Its regional scope, in-house fabrication capabilities, and service-offering breadth closely match Grunau's positioning.
• Comfort Systems USA: Comfort Systems USA (NYSE: FIX) is a publicly traded national provider of HVAC, mechanical, and plumbing services for commercial, industrial, and institutional customers. Its core offering directly mirrors Grunau's mechanical systems scope and represents the largest direct peer in scale.

Broad incumbents

• EMCOR Group: EMCOR Group (NYSE: EME) is one of the largest publicly traded facility services providers in the U.S., delivering mechanical and electrical construction plus building services across commercial, industrial, and utility markets. It is a broader incumbent in the same industry with significantly larger scale than Grunau.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks5 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/grunau-company

Compliance7 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Subsidiaries2 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Grunau Company