SOA Category OG11
Certification for integrated technological systems (plumbing, HVAC, electrical)
Category OG11 covers works in which several technological systems (OS3, OS28 and OS30) are installed or managed simultaneously on the same site and within the same project. It is strategically important for tenders requiring coordination between plumbing, heating and electrical systems, and also strengthens the company’s position in the private sector. The official category description emphasises functional integration and the indivisible nature of the works (OS3-OS28-OS30).
Technical and organisational requirements for OG11 qualification
To fall within OG11, the project must include the combined execution or maintenance of the three specialist categories:
- OS3 – plumbing and sanitary systems, kitchens and laundries;
- OS28 – heating and air-conditioning systems;
- OS30 – electrical, telephone, radiotelephone and television systems.
Minimum shares of the total value of the works
For works to be classified as OG11, the breakdown of activities must meet the following minimum shares.
Each percentage is calculated on the total value of the OG11 works in the individual project, rather than on the requested SOA classification.
Requirements for specialist categories
These percentages apply to 90% of the value of the requested classification.
The resulting amount is the minimum required for each type of work to qualify for the requested classification.
| Specialist category | Minimum share of the OG11 works | Classification requirement calculated on 90% of the requested amount |
|---|---|---|
| OS3 | 10% | 40% |
| OS28 | 25% | 70% |
| OS30 | 25% | 70% |
Peak works
As with the other categories, there are three options for demonstrating the peak works requirement.
- one project with a value of at least 40%;
- two projects with a combined value of 55%;
- three projects with a combined value of 65%.
For OG11 specifically, these percentages must be applied taking into account the allocation by category: 40% for OS3, 70% for OS28 and 70% for OS30.
The following example illustrates how to calculate the requirements and peak works needed for OG11 in classification III-bis, with a value of €1,500,000.00.
Calculation example – category OG11
Application for qualification in classification III-bis (€1,500,000.00)
Total value of the works: €2,430,000
(€1,500,000 × 180%) × 90% = €2,700,000 × 90% = €2,430,000
Requirements for each specialist category
| Specialist category | Minimum value of the works | Calculation |
|---|---|---|
| OS3 | €540,000 | (€1,500,000 × 90%) × 40% €1,350,000 × 40% = €540,000 |
| OS28 | €945,000 | (€1,500,000 × 90%) × 70% €1,350,000 × 70% = €945,000 |
| OS30 | €945,000 | (€1,500,000 × 90%) × 70% €1,350,000 × 70% = €945,000 |
Peak works: the three alternatives
| Specialist category | One project 40% | Two projects 55% combined | Three projects 65% combined |
|---|---|---|---|
| OS3 | €240,000 (€1,500,000 × 40%) × 40% €600,000 × 40% = €240,000 | €330,000 (€1,500,000 × 40%) × 55% €600,000 × 55% = €330,000 | €390,000 (€1,500,000 × 40%) × 65% €600,000 × 65% = €390,000 |
| OS28 | €420,000 (€1,500,000 × 70%) × 40% €1,050,000 × 40% = €420,000 | €577,500 (€1,500,000 × 70%) × 55% €1,050,000 × 55% = €577,500 | €682,500 (€1,500,000 × 70%) × 65% €1,050,000 × 65% = €682,500 |
| OS30 | €420,000 (€1,500,000 × 70%) × 40% €1,050,000 × 40% = €420,000 | €577,500 (€1,500,000 × 70%) × 55% €1,050,000 × 55% = €577,500 | €682,500 (€1,500,000 × 70%) × 65% €1,050,000 × 65% = €682,500 |
Calculation for each specialist category: classification value × specialist category share × percentage of the chosen alternative. The three columns represent alternative ways of demonstrating the requirement. The specialist category share is 40% for OS3 and 70% for OS28 and OS30.
FAQ SOA Category OG11
What is the official “declaratory” of OG11?
OG11 concerns the installation, management and maintenance of coordinated, functionally interconnected technological systems that cannot be executed separately, corresponding to OS3, OS28 and OS30.
Official definition
This category covers the installation, operation and maintenance of coordinated, functionally interconnected technological systems that cannot be carried out separately, belonging to the specialist works categories OS3, OS28 and OS30.
When does a project fall under OG11?
Only when OS3 + OS28 + OS30 are present together in the same site and the same contract, fully integrated.
If only two systems are present (e.g., OS3 + OS28), is it OG11?
No. Without the OS3–OS28–OS30 triad, it is not OG11.
Why is OG11 considered a modern and highly requested category?
Because it certifies the capability to integrate multiple systems: electrical, HVAC, water, automation, safety, and energy. It represents digital and energy transition (smart buildings, hospitals, green schools, IoT infrastructure).
Difference between OG11 and OS categories:
OG11 certifies their integration.
- OS3 → Plumbing and water-sanitary systems
- OS28 → HVAC and thermal systems
- OS30 – Electrical and special systems
Strategic fields for OG11 today:
- Smart buildings and public automation
- Energy efficiency (PV integration, heat pumps, sensors)
- Transport infrastructure (stations, airports, tunnels with integrated systems)
- Data centers and digital infrastructure (cooling + continuity power + security)
OG11 is the ‘technological brain’ of construction projects
What does being OG11-qualified mean in 2025?
It means being prepared for opportunities in energy efficiency and digitalized infrastructure, where systems are integrated into unified control environments.
Which SOA categories are most closely related to OG11?
- OS3 – Plumbing and water-sanitary systems, kitchens, laundries
- OS28 – Heating, thermal and air-conditioning systems
- OS30 – Electrical and special systems
- OG1 – Civil and industrial buildings (when the systems component is predominant)
OG11 acts as a technical bridge between these categories, enabling companies to carry out complex projects that integrate all of them.
CEL Requirements
CELs must certify the simultaneous execution of OS3 + OS28 + OS30 with minimum economic incidence thresholds (10/25/25 and 40/70/70). A CEL for a single system is not sufficient.
The OG11 category is the core of integrated technological systems: it certifies organizational capacity, coordination skills, and the ability to manage complex projects with a high technological and systems-engineering component.
Your next step? Verify the minimum incidence thresholds (10/25/25), consolidate CELs with joint execution (40/70/70), and ensure you have the appropriate OG11 classification. If needed, integrate complementary categories and focus on innovation and training to enhance efficiency (HVAC, automation/BMS, monitoring) in OG11 tenders.
