Koster AG

What Koster AG does

Koster AG is a Swiss building technology company headquartered in Zürich, founded in 1967, that delivers integrated HVAC, plumbing, sanitary, MSRL (Measurement, Control and Regulation), and building automation services to residential, commercial, and industrial customers across the Canton of Zürich and Canton of Aargau. The company operates as a one-stop shop ('Haustechnik aus einer Hand') through approximately 220 specialists distributed across six regional branch offices, supported by an in-house prefabrication workshop in Birmensdorf for control cabinets and components. Service delivery is structured around project-based installation quotes with standardized payment terms (30/30/30/10), recurring maintenance contracts, 24/7 emergency repair services, and consulting for energy optimization and renewable-energy retrofits (heat pumps, photovoltaics).

The core technology stack centers on near hardware-independent building automation ('Gebäudeautomation') enabling remote monitoring, energy optimization based on weather data, email alerting, consumption evaluation, and remote troubleshooting, complemented by an AI-assisted 'Behaglichkeitsgarantie' (Comfort Guarantee) for climate control and a mobile management app (SkyNet 42). Sanitary installations are executed through wholly-owned subsidiary Goldenbohm AG, while subsidiary Alvasys Automation AG (formerly Bänninger+Zolliker, rebranded 2019) trades building automation components in the DACH region. The firm is privately held by a partner group following a 2015 management buyout, holds ISO 9001 certification continuously since 1998, and is a suissetec-certified qualified training company recognized as a Top Lehrbetrieb in 2017.

Name

Koster AG

Legal name

Koster AG

Website

https://kosterag.ch

Company type

Private

Founded year

1967

Operating status

Operating

Headcount range

101–250 employees

Short description

Koster AG is a Swiss building technology company providing integrated HVAC, plumbing, building automation, and MSRL services to residential, commercial, and industrial customers across the Zürich region and Aargau through ~220 specialists at six branches.

Ownership category

akta.pro rank

Product category

Building Technology Services (HVAC, Sanitary, MSRL)

NAICS

Plumbing, Heating, and Air-Conditioning Contractors (238220), Plumbing, Heating, and Air-Conditioning Contractors (23822)

SIC

Refrigeration & Service Industry Machinery (3580), Services-Computer Integrated Systems Design (7373)

akta.pro primary industry

HVAC & Refrigeration Contracting (IMAFALAB)

akta.pro secondary industries

Refrigeration Systems Maintenance (Commercial/Industrial) (BPABACAI), Construction Management & Delivery (EPCM/CMAR/Design-Build Oversight) (EUANALAE)

Keywords

• HVAC installation services
• Building automation systems
• Sanitary plumbing services
• Heating ventilation cooling
• Building technology solutions

Headquarters

HQ city

Zürich

HQ country

Switzerland

HQ region

Europe

Offices9 records

Markets served

GTM type

B2B and B2C

Offering type

Services

Cost components

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

Revenue model

1. Installation Services: Project-based installation of heating, ventilation, air conditioning, and plumbing systems for new constructions, renovations, and retrofits. Revenue generated through quotes with payment terms: 30% deposit, 30% at work start, 30% at completion, 10% after acceptance.
2. Maintenance Contracts: Ongoing maintenance services for installed building technology systems. Customers sign maintenance contracts for regular servicing of heating, ventilation, sanitary, and MSR systems.
3. Repair and Emergency Services: 24/7 emergency repair services for heating, plumbing, and building technology breakdowns. Includes after-hours pikettdienst (on-call service).
4. Consulting and Planning: Technical consulting, energy concept development, and building technology planning services.

Pricing tiers

Go-to-market motion2 records

Distribution channels4 records

Marketing channels6 records

Core offering

Koster AG plans, installs, and services heating, ventilation, climate/cooling, sanitary/plumbing, and building automation (MSRL) systems for residential and commercial buildings in the Zürich and Aargau regions of Switzerland. The company delivers projects from quote through installation, and supports them with maintenance contracts and a 24/7 emergency repair service. Its offering is split between Grossanlagen (complex large-scale installations) and Kleinanlagen (smaller residential and commercial projects), all coordinated through a single contractor.

Product overview

Koster AG is a building technology company (Gebäudetechnik) offering integrated HVAC, plumbing, electrical, and building automation services across two main categories: Grossanlagen (large-scale complex installations) and Kleinanlagen (smaller residential/commercial projects). Core services include heating (Heizung), ventilation (Lüftung), climate/cooling (Klima/Kälte), sanitary systems (Sanitär) installed by subsidiary Goldenbohm AG, and building automation (MSRL/Gebäudeautomation). The company also provides renewable energy solutions (heat pumps, photovoltaics), 24-hour emergency service, maintenance contracts, consulting, and in-house prefabrication of control cabinets. The portfolio operates under a unified 'everything from one source' (aus einer Hand) model, coordinating all building technology trades through a single contact.

Differentiator

Problem solved

Functional benefit

Brands

• Goldenbohm AG: Subsidiary company for sanitary installations serving residential houses, villas, apartment buildings, and commercial/industrial buildings.

Products and services

• Heating Systems (Heizung)

Quantifiable outcome

• 24/7 emergency service availability
• +2 more outcomes

Named customers1 record

Segments4 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

Six partnerships are on record, tiered core and minor.

• Alvasys Automation AGcoreOthers · 1 January 2019Renamed from Bänninger & Zolliker AG in 2019. Specializes in building automation components trade for the DACH region.
• Goldenbohm AGcoreOthers · 1 January 2010Acquired in 2010, specializes in sanitary installations. All sanitary systems are installed by Goldenbohm AG.
• Bänninger+Zolliker AGcoreOthers · 1 January 2008Acquired in 2008, later renamed to Alvasys Automation AG in 2019. The acquired company specializes in building automation components for the DACH region.
• suissetec (Schweizerisch-Liechtensteinischer Gebäudetechnikverband)minorOthersIndustry association membership. The association provides targeted services for quality assurance, including in the training area. Koster AG is a qualified training company.
• IG Altbau (Interessen Gemeinschaft Altbau)minorOthersMembership in the Interest Group for Old Buildings, demonstrating commitment to optimal use of existing building stock.
• Special Olympics SwitzerlandminorOthersSocial responsibility partnership supporting athletes with intellectual disabilities through sports programs that promote self-esteem, physical fitness, independence, and courage to try new things.

Scale indicators6 records

Recent moves13 records

Expansion highlights5 records

Regional players

• R. Nussbaum AG: R. Nussbaum is a Swiss sanitary systems manufacturer and service provider focused on building water supply and drainage. Comparable to Koster AG's Goldenbohm AG subsidiary in the sanitary/plumbing product and installation space, though more product-led than service-led.

Broad incumbents

• Alpiq InTec AG: Alpiq InTec is a Swiss provider of building technology, energy services, and facility management, offering HVAC, electrical, and automation solutions. Comparable to Koster AG across multiple Haustechnik disciplines, but with a national footprint and broader energy-services portfolio.
• Siemens Smart Infrastructure (Switzerland): Siemens Smart Infrastructure supplies building automation, HVAC controls, and energy-management platforms globally and in Switzerland. Comparable to Koster AG's MSRL/building automation and Alvasys Automation AG component offerings, but at a vastly larger scale and with proprietary platform technology.
• ENGIE Services Switzerland (ENGIE Schweiz): ENGIE Schweiz is a major multi-technical services and energy-solutions provider in Switzerland covering HVAC, building automation, and facility management for commercial and industrial clients. Overlaps with Koster AG on large-installation projects and building automation but operates at significantly greater scale and breadth as part of the global ENGIE group.
• Bouygues Energies & Services in Switzerland: Bouygues E&S Schweiz delivers multi-technical building services including HVAC, electrical, and energy management across Switzerland. A larger, broader incumbent competing for the same enterprise and infrastructure projects that Koster AG addresses in its Grossanlagen segment.

Direct peers

• Tobler Haustechnik AG: Tobler Haustechnik is a Swiss full-service Haustechnik contractor offering heating, ventilation, sanitary, and cooling installations. Directly comparable to Koster AG in service scope, Swiss regional focus, and integrated multi-trade delivery model.
• Hoval Group: Hoval is a Liechtenstein/Swiss-headquartered manufacturer and service provider of heating, ventilation, and indoor climate solutions with strong DACH presence. Comparable to Koster AG as an integrated HVAC manufacturer-plus-service player serving similar commercial and residential customers in the same Swiss/DACH market.
• Elcotherm AG: Elcotherm is a Swiss heating technology company specializing in heat pumps, oil/gas boilers, and service. Comparable to Koster AG's heating business line, with overlap in Swiss residential and commercial heating installations, maintenance, and energy-transition offerings.
• Walter Meier (Walter Meier Klimatechnik): Walter Meier is a leading Swiss provider of climate and HVAC services and solutions, offering heating, cooling, ventilation, and building services to commercial and industrial customers. Directly comparable to Koster AG in scope (Haustechnik), customer base (Swiss commercial/residential), and project-plus-service business model.

Emerging players

• Burkhalter Group: Burkhalter Group is a leading Swiss electrical engineering services provider with growing HVAC-adjacent capabilities. Comparable on the MSRL/electrical and building-services side of Koster AG's offering and a potential partner or acquirer of Koster's electrical/MSRL business.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key highlights6 records

Customer concentration

• Facebookfacebook.com/kosterag.ch
• LinkedInlinkedin.com/company/koster-ag
• Instagraminstagram.com/koster_ag

Compliance4 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles11 records

Subsidiaries1 record

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 Koster AG