Design specification for construction products

Traditional design practices have been based on specifying product brand names in design documents. This has often made it difficult for contractors' procurement organizations to substitute products with equivalent alternatives offered by their own framework agreement partners and suppliers, which may be more cost-effective or better suited to the intended application.

For many construction products, such as architectural surface materials, specifying products by brand name remains a practical approach, provided that the designer is able to assess not only the appearance of the product but also the adequacy of its technical performance characteristics for the intended use. However, for many construction products—particularly those within the scope of structural engineering—the European technical language established through CE marking enables product specifications to be based on the essential characteristics declared in the Declaration of Performance (DoP). In this approach, performance requirements are defined for the essential characteristics that are critical to the intended application, using nationally specified and, where necessary, project-specific performance levels expressed as numerical values or performance classes. This method of product specification promotes a systematic approach and facilitates competitive procurement by allowing contractors to compare and select products that meet the specified performance requirements.

With funding from the Building Information Foundation RTS, RT/Talonrakennusteollisuus ry, SKOL ry, Puutuoteteollisuus ry, Julkisivuyhdistys ry, Teräsrakenneyhdistys ry, Suomen Metalli- ja Lasirakenneyhdistys ry and Sahatavaran Lujuuslajitteluyhdistys ry, Phase 6 of the Joint Project on Product Specification in Design has updated and prepared the following model documents to support designers in their work:

1. General Product Specification Guidelines for Structural Types (23 September 2024)

Contents:

• General guidance on the use of the supporting tools, as well as the reference tables cited in the structural type models.
• Properties and requirements for plastic drainage pipes and plastic inspection chambers.
• Explanations of the structural properties of timber products.

2. Appendix 1: Essential Characteristics of Construction Products and Their Requirements in Finland (21 October 2024)

3. Appendix 2: Structural Type Models (3 October 2024)

(Appendices 2.1 and 2.2 updated on 3 February 2026)
4. – 2.1 General Structural Type Models (pdf) (dwg)

5. – 2.2 Surface Structure Type Models (pdf) (dwg)

6. – 2.3 Balcony Railing Structural Type Models (pdf) (dwg)

7. – 2.4 Renovation / Refurbishment Structural Type Models (pdf) (dwg)

8. – Guideline: Airborne Sound Insulation of Walls Between Apartments (10 June 2024)

9. – Guideline: Design of Metal Plate Connected Timber Structures (25 March 2024)

Notes

Note 1: The DWG versions can be edited using AutoCAD.

Note 2: It is strongly recommended to read the introductory text in the PDF versions of the structural type models before starting to modify the AutoCAD (DWG) versions.

The seventh phase of the project is intended to continue developing product specifications for new product groups and to expand the scope of application of the structural type models.

Feedback on the documents can be sent to Kai Renholm at kai.renholm@rakennustieto.fi.