SIA 105-K (2018) – Fee Calculation Aid for Landscape Architecture
The SIA 105-K (2018) is a supplemental document to the Ordnung SIA 105 (Ordnung für Leistungen und Honorare der Landschaftsarchitektinnen und Landschaftsarchitekten). Issued by the Schweizerischer Ingenieur- und Architektenverein (SIA), this calculation aid serves as a non-binding framework for determining professional fees for landscape architecture services in Switzerland. This edition, effective from November 1, 2018, was published as a transitional solution following recommendations from the Swiss Competition Commission (Wettbewerbskommission or WEKO) to ensure antitrust compliance while maintaining industry standards for fee transparency.
The document defines the regulatory scope for landscape planning, garden design, and the management of green spaces. It provides two primary methods for remuneration: calculation based on effective time expenditure (effektiver Zeitaufwand) and calculation based on construction costs (aufwandbestimmende Baukosten). The framework covers projects ranging from residential gardens and sports facilities to urban plazas and the conservation of historical parks. It establishes specific formulas for predicting time expenditure ($T_p$) and calculating total honoraria ($H$), incorporating variables such as the degree of difficulty ($n$), team factors ($i$), and special performance factors ($s$).
This guidance is structured into specific articles addressing staff qualification categories, construction cost definitions, and the distribution of fees across various project phases. It aims to provide landscape architects and clients with a standardized basis for individual contract negotiations.
Fee Calculation Based on Effective Time Expenditure
According to Article 6, fees based on time expenditure can be agreed upon using qualification categories, average hourly rates, or specific salaries. This method is specifically indicated for planning tasks where the scope is difficult to estimate or for projects where construction costs are below CHF 100,000.
- Qualification Categories (A-G): Staff are classified based on function and experience, ranging from Project Leaders for interdisciplinary large-scale projects (Category A) to apprentices (Category G).
- Experience Levels (1-3): Three levels account for professional experience, where Level 3 typically requires a tertiary degree and at least 5 years of experience in the designated function.
- Calculation Formula: The total fee ($H$) is calculated as the sum of working hours ($T_t$) multiplied by the offered average hourly rate ($h$).
Calculation Based on Construction Costs
Under Article 7, the honorarium is determined relative to the construction costs of the processed facility. This method utilizes the predicted time expenditure ($T_p$), which is derived from the statistical median of time required for similar projects.
- Construction Costs (B): Includes financial expenditures for systems and components processed by the landscape architect, excluding VAT, rebates, and land acquisition costs.
- Degree of Difficulty (n): A factor ranging typically from 0.8 to 1.2, reflecting technical, artistic, and organizational complexity.
- Team Factor (i): Accounts for team-specific deviations from the estimated time expenditure.
- Special Services (s): A factor representing additional responsibilities or high economic benefits provided to the client.
Open Space Categories and Project Phases
The document classifies various building projects into five Freiraumkategorien (I-V) to determine the complexity factor. For example, simple sports fields or technical facilities fall into Category I, while complex botanical gardens or high-end private gardens fall into Category V.
- Phase 3 (Project Planning): Includes preliminary projects (4-8%) and construction projects (10-18%).
- Phase 4 (Tendering): Covers the creation of tender plans and contract awarding (18%).
- Phase 5 (Realization): Includes execution projects (16%) and site management/cost control (29%).
- Phase 6 (Management): Relates to maintenance and renewal services, often agreed upon separately.
Frequently Asked Questions
Which construction costs are excluded from the fee calculation according to SIA 105-K?
According to Article 7.5.14, costs for land acquisition, financing, public fees, insurance, and the honoraria of the landscape architect or other specialists are not included in the fee-relevant construction costs (B).
What is the standard difficulty factor 'n' for normal projects?
Unless otherwise agreed, the degree of difficulty factor (n) is set to 1.0, reflecting a project with normal planning and execution requirements (Article 7.6.2).
How are qualification levels determined for staff?
Level 1 is for staff with under 4 years of experience and no secondary/tertiary degree; Level 2 is for those with degrees or 4 years of experience; Level 3 is for those with degrees and at least 5 years of experience (Article 6.2.3).
What happens if a project is cancelled before completion?
Article 7.5.15 states that if a project is not executed, the effort for services rendered is calculated based on the last cost estimate, with non-relevant amounts deducted.
How are repeat installations handled in the fee calculation?
If an order involves multiple identical installations, Article 7.12.1 allows for a reduction in the fee if a clear simplification of the architect's work is expected.
Is travel time considered working time under SIA 105-K?
While previous editions included it, the 2018 revision (Vorwort zur Übergangslösung) explicitly states that the designation of travel time as working time is no longer a general recommendation for antitrust reasons and must be negotiated project-specifically.
