ASHRAE Standard 189.1 – The Green Standard

December 5th, 2012 | Related: ,

Is LEED being replaced? Smart building owners and developers are keeping their eye on the spread of ASHRAE Standard 189.1, which in some areas and agencies, is supplanting the LEED rating system as the standard for sustainable building requirements. Here’s a quick overview of what you need to know about this new standard, how it compares to LEED, and what it might mean for your current and future projects.

ASHRAE Standard 189.1, “The Green Standard,” was released in 2011 as a new standard for designing, building, and operating green buildings. The comprehensive standard was jointly sponsored by ASHRAE, USGBC, and the Illuminating Engineering Society, and is designed to help achieve high performance buildings on a more widespread basis than ever before.

How is it used?

Standard 189.1 is intended for adoption into model building codes to guide the development of all building types except low-rise residential. Municipalities around the country have already begun including the standard in their building code updates, in addition to some government agencies. We expect to see many more adoptions in the coming months and years. Standard 189.1 is also included in the International Green Construction Code as an alternative compliance path.

How does it compare?

The new standard borrows from existing green building methods, integrating existing ASHRAE standards with updates and utilizing a similar framework to LEED. Standard 189.1 incorporates ASHRARE Standard 90.1 (Energy Standard for Buildings Except Low-Rise Residential Buildings) with modifications, ASHRAE 62.1 (Ventilation for Acceptable Indoor Air Quality) with modifications, and ASHRAE Standard 55 (Thermal Environmental Conditions for Human Occupancy) in full. Although the new standard appears similar to LEED at first glance, it is not a design guide or a rating system and is intended to be adopted as a building code.

What does it look like?

Standard 189.1 takes on a new and comprehensive structure unlike any other ASHRAE standard to date.  Like LEED, it covers 6 sections:  Site Sustainability, Water Use Efficiency, Energy Efficiency, Indoor Environmental Quality, Buildings Impact on Atmosphere, Materials & Resources, and Construction & Plans for Operation. Standard 189.1 requires project teams to comply with a selection of mandatory provisions, but the rest of the requirements can be pursued either on a prescriptive or performance basis. This allows much more flexibility in documentation requirements, distinguishing itself from other green building guides and rating systems.

  • Mandatory Provisions:  Set of criteria that must be complied with by all projects.
  • Prescriptive Option:  Requires projects to meet criteria in a specified manner and provides a simple way to show compliance that involves little or no calculations.
  • Performance Option:  Requires projects an alternative way to show compliance that is typically more complex then the prescriptive option.

Sections Breakdown of Standard 189.1 – A Quick Look

  • Site Sustainability

Mandatory Provisions cover allowable sites, urban heat island, and light pollution issues.

    • Key Points:
      • Urban Heat Island – Standard 189.1 focuses on site impact issues in addition to building impact. The standard requires 3 year aged SRI values of 64 (low slope) and 29 (steep slope) for site.  The 3 year aged SRI of 64/29 also covers roof insulation. Standard 90.1-2010 focuses only on building energy impact issues.
      • Light Pollution – Standard 189.1 address light trespass, pollution and glare issues. The standard requires compliance with backlight up-light and glare ratings (BUG). Standard 90.1 only indirectly controls light pollution specifying maximum allowable power densities and required control.
  • Water Use Efficiency

Mandatory Provisions cover Site Water Use, Building Water Use, HVAC Systems & Equipment, and Water Consumption Management.

    • Key Points:
      • Focuses on overall demand reduction for building water use as well as site water use.
  •  Energy Efficiency

Mandatory Provisions for Renewable Energy Preparedness, Energy Consumption Metering, and Data Storage for minimum 36 months.

    • Key Points:
      • Standard 189.1 has more stringent requirements than Standard 90.1 with respect to building envelope, envelope commissioning, demand control ventilation, fan power duct sealing and lighting
      • Prescriptive requirement of the standard requires projects to have some amount of onsite renewable energy production. Based on roof square footage and number of stories. ASHRAE 90.1 has no onsite renewable energy requirement.
  • Indoor Environmental Quality

Mandatory Provisions include Outdoor Airflow, Tobacco Smoke Control, Outdoor Air Delivery Monitoring, Filtration and Air Cleaning, Daylighting, Thermal Comfort, Acoustics, Contaminant Source Control, and Building Entry Systems.

    • Key Points:
      • Requirements are similar to USGBC’s LEED 2009 NC.
      • The standard allows only the ventilation rate procedure and requires permanently mounted devices that measure incoming outdoor air flow.
  • Building’s Impact on Atmosphere, Materials and Resources

Mandatory Provisions include Construction Waste Management and No CFC-based Refrigerants.

    • Key Points:
      • Requirements are similar to USGBC’s LEED 2009 NC Prescriptive Option restricts use of endangered  wood species, recycled content, regional material requirements.
      • Performance Option includes life cycle assessments.
  • Construction and Plans for Operation

Mandatory Provisions emphasize Commissioning, IAQ Construction Management, Measurement and Verification of Water, Energy and Outdoor Air-flow, and Maintenance Planning.

    • Key Points:
      • Commissioning is considered standard on a project and includes a two level approach based on size.
      • Measurement and Verification requires plans for operation and requirements for monitoring devices.

A building that complies with Standard 189.1 should easily be able to achieve a LEED Silver rating. If ASHRAE Standard 189.1 is required in your jurisdiction, GreenShape can help your project comply with the standard offering guidance throughout design and construction, helping you to reach both the ASHRAE and LEED performance thresholds.

For more details regarding ASHRAE Standard 189.1, tips, and tools for adopting the standard, visit ASHRAE’s website.