Grunau Company
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.
- Company typePrivate
- Founded1920
- HeadquartersOak Creek, United States
- Headcount251–500
- GTM typeB2B
- OfferingServices
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.
Grunau Company firmographics
Firmographics- 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
Where Grunau Company is headquartered
LocationHeadquarters
- HQ city
- Oak Creek
- HQ country
- United States
- HQ region
- North America
Offices2 records
Markets served
Grunau Company business model
Business model- GTM type
- B2B
- Offering type
- Services
- Cost components
- Personnel, Supply Chain, Operations, Technology or R&D, Marketing or Sales
Revenue model
- 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.
- 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
| Model | Billing | Price |
|---|---|---|
| Transaction based/ take rate | Pay-as-you-go | Credit card payment processing with 3% service charge |
Go-to-market motion1 record
Distribution channels1 record
Marketing channels4 records
Grunau Company product offering
Product offeringCore 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
Companies that use Grunau Company
Customer profileNamed customers9 records
Segments8 records
Ideal customer profiles2 records
Grunau Company technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature5 records
Grunau Company partnerships and signals
Strategic signalScale indicators4 records
Recent moves8 records
Expansion highlights5 records
Grunau Company competitors and assessment
Company assessmentDirect 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
Grunau Company social profiles
Digital presenceGrunau Company compliance and trust
Trust signalCompliance7 records
Grunau Company financial estimates
Financial estimateRevenue estimate
Valuation estimate
Grunau Company leadership team
Management profileNumber of profiles
Profiles2 records
Grunau Company subsidiaries and ownership
Company hierarchySubsidiaries2 records
Grunau Company funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Grunau Company M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Grunau Company
What does Grunau Company do?
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.
Is Grunau Company a public or private company?
Grunau Company is a private company. It is classified as corporate owned and is currently operating.
When was Grunau Company founded?
Grunau Company was founded in 1920. It employs 251 to 500 people.
Where is Grunau Company based?
Grunau Company is headquartered in Oak Creek, United States, in the North America region.
How does Grunau Company make money?
Two revenue lines are on record. Mechanical Systems Construction is the primary driver. The others are 24/7 Service and Maintenance.
Who are Grunau Company's main competitors?
Direct peers on record are Limbach Holdings, Southland Industries, U.S. Engineering Company Holdings and Comfort Systems USA. EMCOR Group is listed as a broad incumbent.
Does Grunau Company have an API?
No public API is recorded for Grunau Company.