Sommer Informatik GmbH

What Sommer Informatik GmbH does

Sommer Informatik GmbH is a privately held German software company headquartered in Rosenheim, founded on January 1, 1996 by Robert Sommer and led since 2021 alongside Alexander Sommer. The company develops two distinct software lines serving the German property and construction ecosystem. The flagship is the Capitol suite, a modular real estate and property management platform covering residential, commercial, and WEG (Wohnungseigentümergemeinschaft / apartment owner association) administration, including cost allocation, operating cost billing, owner/tenant portals (Capitol Talk), and digital owner assembly. Capitol WEG-Abrechnung and Capitol BK-Abrechnung are positioned as the only auditor-certified software for legally compliant operating cost billing in Germany. The second line comprises four building physics tools — WINISO, GLASGLOBAL, WINSLT, and WINTHS — used by architects, engineers, and consultants for thermal bridge, glass statics, CE marking, and thermal stress calculations.

The technology stack centers on certified, compliance-driven calculation engines rather than AI or platform orchestration. Capitol holds a DATEV interface provider certification (since 2017), a GDPR/DSGVO compliance posture with a designated Data Protection Officer (Christina Sommer), and cloud deployment options introduced in 2020. The most recent capability addition is an AI-supported key recognition and management application (2025), developed with TH Rosenheim students and representing the company's first computer-vision product.

The business model is a niche, direct-sales enterprise software motion within Germany only. Customers include professional property management companies, WEG administrators, municipalities, banks, breweries with real estate holdings, foundations, churches, and asset managers across the country. Distribution is primarily through direct website inquiries and demo requests, supplemented by BVI trade show participation. The company has 1–10 employees, has never raised institutional capital, and operates as a founder/family-owned GmbH with no subsidiaries or M&A activity. Revenue is not publicly disclosed.

Name

Sommer Informatik GmbH

Legal name

Sommer Informatik GmbH

Website

https://sommer-informatik.de

Company type

Private

Founded year

1996

Operating status

Operating

Headcount range

1–10 employees

Short description

Sommer Informatik GmbH is a founder-owned German software company that develops the Capitol property management suite and a building physics software line (WINISO, GLASGLOBAL, WINSLT, WINTHS) for property managers, WEG associations, municipalities, banks, and construction professionals across Germany.

Ownership category

akta.pro rank

Product category

Property Management Software

NAICS

Real Estate Property Managers (53131), Software Publishers (5132), Computer Systems Design Services (541512)

SIC

Real Estate Agents & Managers (For Others) (6531), Services-Computer Programming Services (7371)

akta.pro primary industry

Association Maintenance, Vendor & Capital Project Management (BPAJAHAM)

akta.pro secondary industry

Building Information Modeling (BIM) & Digital Design Services (BPAHAKAK)

Keywords

• Property management software
• Building physics software
• Real estate administration
• Thermal bridge analysis
• WEG cost accounting

Headquarters

HQ city

Rosenheim

HQ country

Germany

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Software

Cost components

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

Revenue model

1. Building Physics Software Licenses: Sale of specialized building physics software products including WINISO, GLASGLOBAL, WINSLT, and WINTHS for thermal analysis, glass statics, and related calculations
2. Real Estate Management Software (Capitol): Professional real estate management software licenses including Capitol Hausverwaltung, WEG-Verwaltung, WEG-Abrechnung, and BK-Abrechnung, with cloud-based deployment options available since 2020

Go-to-market motion1 record

Distribution channels2 records

Marketing channels9 records

Core offering

Sommer Informatik GmbH develops and sells two software product lines: (1) Capitol, a modular real estate and property management suite for professional property managers, WEG (apartment owners' associations), municipalities, banks, and commercial real estate operators, including cost allocation, operating cost billing, owner meeting, and tenant/owner portal modules; and (2) Building physics software (WINISO®, GLASGLOBAL®, WINSLT®, WINTHS®) for thermal bridge analysis, glass statics, thermal transmittance/CE marking, and thermal stress analysis. The Capitol suite is the flagship real estate platform with over 25 years of development, cloud-based deployment, and certified DATEV interface integration.

Product overview

Sommer Informatik GmbH offers two distinct software product lines: (1) Capitol – a modular real estate/property management suite comprising six integrated modules for professional property management, WEG administration, cost allocation, operating cost billing, and online portals for both managers and tenants/owners; and (2) Building Physics software – a suite of four specialized tools (WINISO®, GLASGLOBAL®, WINSLT®, WINTHS®) for thermal bridge analysis, glass statics, thermal transmittance/ CE marking, and thermal stress analysis. Capitol is the company's flagship real estate platform with over 25 years of development history, cloud-based deployment options, and certified DATEV interface integration.

Differentiator

Problem solved

Functional benefit

Brands

• WINISO: Building physics software for Uf, Ψ, thermal bridges, isotherms, fRsi values.
• GLASGLOBAL
• WINSLT
• WINTHS
• Capitol

Products and services

• Capitol Hausverwaltung Expert software for professional real estate and property management, providing comprehensive functionality for managing rental and commercial properties, land, and apartment ownership communities. Targets property management companies, WEG administrators, banks, and municipalities in Germany.
• Capitol WEG-Verwaltung

Quantifiable outcome

• Germany-wide recognized accounting results - legally compliant across all German states
• +1 more outcomes

Named customers12 records

Segments6 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration1 record

AI capability2 records

Feature11 records

Partnerships

Five partnerships are on record, tiered core and minor.

• DATEVcoreTechnology or IntegrationDATEV-Schnittstellen Anbieter certified since 2017. Capitol software integrates with DATEV accounting systems, allowing seamless data exchange for property management companies and ensuring compliance with German accounting standards.
• BVI (Bundesverband der Immobilienverwalter)coreStrategic or Co-development PartnerBVI Fördermitglied (promotional member) since 2019. Professional association for property managers in Germany. Partnership includes joint development of WEG solutions and digital owner meeting functionality.
• Synergie Kommunal GmbHminorStrategic or Co-development PartnerCooperation since 2007 focused on municipal property management solutions. Specializes in meeting the specific needs of German municipalities.
• Haus & Grund Deutschland Verlag und Service GmbHminorStrategic or Co-development PartnerCooperation since 2005 with the property owners' association publishing house, providing specialized solutions for private property owners.
• TH Rosenheim (Technische Hochschule Rosenheim)minorStrategic or Co-development PartnerUniversity partnership for innovation, including the 2025 development of AI-supported key recognition and management application for property managers.

Scale indicators3 records

Recent moves8 records

Expansion highlights5 records

Direct peers

• Haufe Group: German software and content provider whose Haufe Hausverwaltung line competes head-to-head with Capitol in residential property management. Comparable in segment focus but materially larger in headcount, content library, and accounting/tax workflow integration.
• Casavi GmbH: Cloud-native tenant communication and property management platform widely adopted by German property managers. Represents the modern, mobile-first delivery model that competing legacy on-prem tools like Capitol are working to match.
• Domus 4000: Long-standing German property and WEG management software vendor with comparable modular coverage (Domus WEG, Domus Hausverwaltung). Direct competitor to Capitol in mid-market property manager and HOA accounts in Germany.
• GFOS Software: German software house with property and real estate management offerings alongside broader workforce/time-tracking modules. Competes with Capitol in mid-to-large property management accounts and brings integrated ERP-style capabilities.
• Lardi Software (Lardi & Partner): German vendor of Lardi Hausverwaltung software for residential and WEG property management. Directly comparable product scope and target buyer to Sommer Informatik's Capitol line.
• Aareon AG: Leading European provider of property management software (WODIS, Blue Eagle) and part of the Aareal Bank group. Directly competes with Sommer Informatik's Capitol suite in German WEG and property manager accounts, with substantially larger scale and broader module coverage.

Others

• DATEV eG: Dominant German cooperative providing tax, accounting, and ERP software used by most tax advisors and SMBs. Not a direct competitor but a critical ecosystem partner — Capitol's DATEV interface certification (since 2017) is core to its accounting workflow value proposition.

Broad incumbents

• immowelt GmbH: Major German real estate marketplace and software group offering broader tools (listings, CRM, manager workflows). Adjacent rather than directly overlapping with Capitol's accounting/WEG core, but a large incumbent shaping buyer expectations in the same German market.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• YouTubeyoutube.com/user/SommerInformatikGmbH
• LinkedInlinkedin.com/company/sommer-informatik-gmbh

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles3 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 Sommer Informatik GmbH