Understanding Specification Types: A Comprehensive Guide

Let’s delve into the intricacies of construction specifications, the indispensable blueprint for architects, engineers, and contractors. Our focus narrows down to three primary types – prescriptive, performance, and descriptive. Understanding specification types is a crucial first step to better understanding the world of specification writing and development.

Prescriptive Specifications
  • Exacting Details: Prescriptive specs take the lead, furnishing a meticulous breakdown of products or materials. From dimensions to quality standards and installation guidelines, every facet is meticulously detailed.
  • Code Compliance and Aesthetic Precision: Consider prescriptive specs the tool of choice when a specific product is mandated for code adherence or selected for its aesthetic prowess. If a particular material steals the spotlight, prescriptive specs lay out the specifics.
Performance Specifications
  • Outcomes Rule: In contrast to prescriptive specs, performance specifications are outcome-driven. They delineate the desired results, granting the contractor or supplier the autonomy to select a fitting product.
  • Flexibility and Ingenuity: Seeking flexibility? Performance specs open the door to innovative product choices and construction techniques, giving contractors the latitude to push boundaries.
Descriptive Specifications
  • Precision with Flexibility: Descriptive specs strike a balance between the precision of prescriptive and the flexibility of performance specifications. They offer detailed performance criteria alongside a curated list of products that meet the requirements.
  • Preferred Choices with Alternatives: Often utilised when a preferred material is favoured, yet alternative options are acceptable, descriptive specs provide the liberty to choose from an array of suitable products while adhering to performance criteria.

In summary, the choice between prescriptive, performance, or descriptive specifications hinges on the project’s distinct requirements.

  • Prescriptive Specs: Thoroughly detailed, ideal for specific products, code compliance, and aesthetic preferences.
  • Performance Specs: Outcome-focused, offering flexibility in product selection and fostering innovation.
  • Descriptive Specs: Melding precision with flexibility, apt for projects with preferred products but open to alternatives.

Understanding these specifications is critical for informed decision-making aligned with the project’s objectives. Each type has its advantages and drawbacks, necessitating a judicious selection based on the specific demands of the construction project.


At SCLspec, specifications are not just a part of what we do – they’re our passion. This drives our unwavering commitment to offering dedicated support to our architectural clients. Our mission is clear: to deliver tailored specification solutions that seamlessly align with the distinctive requirements of each project we work on. Do you have a project that needs specification expertise? Contact us to set up a meeting.