SIA 108 (2003) – Regulation for Engineer Services and Fees in Building Installations
The Ordnung SIA 108 (2003 edition) is a regulatory standard issued by the Swiss Society of Engineers and Architects (SIA). Formally designated as Swiss Standard SN 508 108, this document establishes the contractual and financial framework for services provided by mechanical, electrical, and specialist engineers within the building installations sector in Switzerland. It functions as a legal and professional benchmark for defining the rights and obligations of both clients and engineers during the planning and execution of construction projects.
The scope of the regulation covers a wide array of technical domains, including HVAC (Heating, Ventilation, Air Conditioning, Cooling), Sanitary engineering, Electrical installations, and MSRL-Technik (Measurement, Control, Regulation, and Management Technology). The document is structured into eight primary articles, detailing general contract conditions, the professional standing of the engineer, specific service descriptions aligned with the SIA 112 performance model, and precise methodologies for fee calculation based either on effective time expenditure or construction costs.
This 2003 edition replaces the 1984 version and various subsequent recommendations. It provides a standardized basis for individual contracts, ensuring that technical coordination and leadership roles are clearly delineated across all project phases from strategic planning to facility management.
Contractual Duties and Professional Standing
Article 1 and 2 define the legal relationship between the engineer and the client. The engineer is obligated to exercise a Sorgfaltspflicht (duty of care), acting as a fiduciary to the client while remaining independent of suppliers and contractors. Key responsibilities include:
- Art. 1.3.20 Treuepflicht: Prohibition of accepting personal favors from third parties and the requirement to maintain confidentiality regarding project data.
- Art. 1.3.50 Abmahnungspflicht: The duty to warn the client about unsuitable instructions, particularly regarding costs, quality, or deadlines.
- Art. 1.11 Verjährung: General claims expire after ten years, while liability for building defects is limited to five years.
- Art. 2.3 Gesamtleiter: Definition of the lead engineer role, responsible for designing the work and coordinating all specialist technical personnel.
Service Descriptions and Project Phases
The regulation categorizes engineer services into six distinct phases, ensuring compatibility with the broader SIA 112 model. These phases distinguish between Grundleistungen (basic services) and besonders zu vereinbarende Leistungen (specifically agreed additional services):
- Phase 1: Strategische Planung: Needs formulation and solution strategies.
- Phase 2: Vorstudien: Project definition, feasibility studies, and selection procedures.
- Phase 3: Projektierung: Preliminary project, construction project, and the permit application process.
- Phase 4: Ausschreibung: Tendering, bid comparison, and award proposals.
- Phase 5: Realisierung: Implementation project, construction management, commissioning, and completion.
- Phase 6: Bewirtschaftung: Operation and maintenance oversight.
Methodology for Fee Calculation
Articles 6 and 7 provide the mathematical foundations for remuneration. Fees can be determined through three primary models:
- Effective Time Expenditure (Art. 6): Based on qualification categories ranging from category A (Lead Engineer/Expert) to G (Drafter/Apprentice).
- Building Costs (Art. 7): Calculated using the formula H = Tp s h, where Tp is the predicted time requirement, s is a factor for special services, and h is the hourly rate.
- Lump Sums: Fixed fees or global budgets agreed upon before project commencement.
Fee calculations involve specific coefficients, including n (degree of difficulty) and r (adjustment factor for local or organizational influences). The Teamfaktor (i) accounts for the specific composition and efficiency of the assigned engineering team.
MSRL-Technik Special Provisions
Article 8 addresses the specific requirements for MSRL-Technik (Measurement, Control, Regulation, and Management Technology). It mandates a division of labor between HLKSE engineers and MSRL specialists, assigning the latter responsibility for system integration and technical coordination.
Frequently Asked Questions
What is the standard retention period for project documents according to SIA 108?
Per Art. 1.3.70, the engineer must preserve original documents or usable copies for a period of ten years following the completion of the assignment.
How does the regulation handle repeat buildings of the same design?
According to Art. 7.14, a fee reduction is applicable for multiple identical buildings or installations at the same location if a clear simplification of services is achieved.
What is the limitation period for construction defects under this standard?
Claims regarding building defects expire five years after the acceptance of the work, as specified in Art. 1.11.21.
What factors influence the 'degree of difficulty' (n) in fee calculations?
The degree of difficulty is determined by the complexity of the technical installation, the level of innovation required, and the extent of responsibility, with values typically ranging from 0.6 to 1.6.
Are VAT and travel expenses included in the basic engineer's fee?
No, per Art. 5.1 and Art. 1.10, VAT is billed separately. Travel times and expenses are considered additional cost elements (Nebenkosten) per Art. 5.3 and 5.4.
What is the maximum allowed advance payment for engineering services?
According to Art. 1.4.40, the engineer is entitled to installment payments of at least 90% of the value of services contractually performed.
