It’s Here! The Phius Certification Guidebook v3.0

SONY DSCIn this week’s blog, Phius Associate Director Lisa White introduces the Phius Certification Guidebook v3.0 and explains how to get the most out of the newest guidebook iteration.

The Phius Certification Guidebook is the one-stop-shop for all things related to the Phius project certification program.

The guidebook contains information ranging from Tips for Designing a Low Cost Passive Building to Energy Modeling Protocols and What to Avoid. It continues to evolve alongside Phius’ growing certification program and standard updates. 

Guidebook CoverOne great reason to certify a project is to share knowledge with the passive building community, which accelerates growth. This guidebook is the keeper of that knowledge as well as lessons learned from the expanding base of certified projects. The Phius Certification team receives a myriad of questions from project teams related to unique circumstances and first-time design decisions that often require developing new guidelines and protocols to be applied on future projects — and those end up in the Guidebook. On top of that, the detailed review of projects throughout design and construction illuminates opportunities for the certification team to improve the guidance we provide to our constituents.

Version 1.0, released five years ago to support PHIUS+ 2015, clocked in at 87 pages. Version 2 followed to support PHIUS+ 2018 at 157 pages, and the most recent update, Version 3, supports Phius 2021, with 190 pages. The guidebook is a key resource for Phius professionals — but we’re often told it’s too long! I’m certain it can feel much shorter, and be incredibly useful, if you know how to navigate it. Anyone can get around a big city with the right map!

View this Table of Contents: Updates Summary which outlines what is new and updated in v3.0.

The document is split into 8 main sections followed by appendices.

The Sections

  • Sections 1 & 2 contain high-level information that is invaluable to first-time project teams and building owners/clients.
  • Section 3 is arguably the most important section, outlining all the certification requirements. Under Phius 2021, there are substantial updates to this section, most notably outlining the requirements of the performance and prescriptive paths side by side, as well as comparing and contrasting how each path handles items such as passive and active conservation strategies.
  • Sections 4 & 5 are key for setting expectations and understanding the workflows and fees associated with the certification process. There is a great high-level graphic showing three phases of certification steps at the beginning of section 4.
  • Section 6 is chock full of detailed energy modeling protocol. This section is laid out in order of the WUFI® Passive tree structure, guiding modelers top down with information ranging from early design defaults to detailed inputs for unique situations.
  • Sections 7 & 8 outline monitoring building performance as well as additional certification badges available. 

The Appendices

    • Appendix A is a consolidated resource about renewable energy. It explains how it can be used in the calculation of source energy use, and guidelines for procuring off site renewable energy.
    • Appendix B is likely the most often overlooked section, while also the appendix most referenced in project certification reviews. This appendix outlines the prescriptive approach to achieving moisture control in opaque assemblies. This most recent update splits this appendix into four types of guidelines: general, for walls, for roofs, and for floors. Do yourself a favor and vet the assemblies used on your next project (certifying or not!) against the guidelines listed here.
    • Appendices C & D are carried over from the previous version, outlining how to assess when a cooling system is recommended (App C) and internal load equipment tables for non-residential buildings (App D).
    • Appendices E, F, & G are great resources for the Phius Certified Rater or Verifier.  Appendix E is the Phius Certified Rater/Verifier manual. It outlines detailed technical inspection and field requirements, post-construction requirements, as well as how to maintain or renew the professional credential. Appendix F describes the procedure to prepare the building for airtightness testing, while Appendix G provides the onsite testing requirements for multifamily buildings.
    • Appendix H describes the Phius 2021 target setting updates, similar to what was found in the previously released “Standard Setting Documentation”
    • Appendix I is new to this version, and holds important information — most notably tips for passive building design about keeping costs low, assembly & window selection, and ventilation systems.
    • Appendix J talks about Co-Generation on-site, and how it affects the source energy factor for natural gas or grid electricity used on-site (depending on how the co-gen is prioritized). This is carried over from a previous version.
    • Appendix K is brand new, outlining definitions and requirements for electric vehicle charging infrastructure to supplement the requirement outlined in Section 3. EV capability is required in some fashion for all residential Phius 2021 projects.
    • Appendix L is also brand new and only applies to Phius CORE projects, as it describes electrification readiness requirements for combustion equipment. As a reminder, fossil-fuel combustion on-site is only permitted for Phius CORE projects, and not allowed for projects pursuing Phius ZERO or Phius CORE Prescriptive.
    • Appendix N closes out the document with normative information. Most notably, N-7 describes many of the underlying formulae for the Phius CORE Prescriptive path which is brand new to Phius 2021. It also contains the formulas and calculation methods used for lighting and miscellaneous electric load calculations, for example.

General Tips

  1. Utilize the Table of Contents and click to the section you need.
  2. Use the ‘find’ function (Ctrl+F) when in doubt of where to look to search for keywords. If taking this route, take note of what section your results are in – for example, is it a requirement or just informative?
  3. Bookmark the Guidebook link! (And follow Phius’ newsletters to be sure you’re aware when new versions are released).
  4. If you are the…
    1. Building Owner/Client — read Sections 1.1-1.4 and Appendix I-1 and review the graphic on the first page of Section 4.
    2. Project Team Member — read through Section 3 one time in its entirety if Phius Certification is a goal of the project. It’s only 18 pages, there are tables and pictures, and you can make it an excuse to have a beer.
    3. Project Submitter — read through Section 4 one time to set expectations, you will be happy you did. Also note Section 2.2, “Yellow Flag” items.
    4. CPHC / Energy Modeler — bookmark Section 6 for reference as you work through the WUFI Passive model.
    5. Phius Certified Rater/Verifier — bookmark Appendix E & F.
    6. One who loves the nitty gritty of passive building — print it, read it cover to cover.

Each iteration of the Guidebook reflects the aggregate knowledge gained by your efforts. Thank you! Feel free to use the comments section below for suggestions and questions.

Phius and Housing Equity: We Can Do This

What do we mean when we say equity in housing? Is it providing a place for all unhoused populations to live? Is it creating enough resources so that everyone has housing security, no matter their class, race, or age? What about high quality housing?

Finch Cambridge, an affordable housing project that won Best Overall Project in Phius' 2020 Design Competion.

Finch Cambridge, an affordable housing project that won Best Overall Project in Phius’ 2020 Design Competion.

Homes and apartments built to the Phius standard are airtight, energy efficient, super insulated, and low maintenance. They are comfortable, quiet, and provide a quality of life. These dwellings provide hard-to-find clean, high quality air, because the ventilation brings in fresh, filtered air and exhausts the stale air, something the coronavirus pandemic has shown is essential to mitigate spread of the virus. Better indoor air quality produces better health outcomes for people with chronic conditions like asthma.

Does your definition of housing equity include the quality of housing? It does for Phius.

Comfortable, well-built, and sustainable homes do not have to be for only the upper class. This is a policy issue. The cities and states of our country owe it to low-income citizens to provide them with a home that keeps them safe, does not strain their finances, and improves their quality of life. Affordable multifamily passive housing has proven time and again that it can be achieved at the same cost as a less sustainable or less reliable home. Single-family homes are being delivered at costs that range from 5 to 10 percent more than conventional buildings. Everyone should live in housing that is reliable and resilient.

Affordable housing, how do we define that? Usually it means housing built for lower-income individuals and families, those on a tight budget. It should also mean housing that is affordable to maintain and to heat or cool. It is not affordable if the occupants have to make a choice between paying for food and paying their utility bills. Multifamily buildings built to the Phius standard use 40-60% less energy than a comparable building built to code, resulting in similar reductions to utility bills.

Homes built to the Phius standard are resilient and reliable. In 2021, the state of Texas froze when its power grid failed. The information from the passive houses we have from Texas show that the temperatures in the building never came close to freezing. Families would have been able to stay in their home and no pipes would have burst, saving hundreds if not thousands of dollars in repairs and replacement.

Imagine living in a home that maintains its temperature no matter the season outside; that weathers severe temperature swings, and costs you less money to live in. Did you feel your stress levels lower just a bit? Don’t your children deserve to live like that? Doesn’t everyone’s child deserve that? How about your parents too?

The infrastructure can be created. This country can do it for its people.

How do we do this? Reach out to your city council, to the people who represent you on the most local level, to educate them about the benefits of passive building to the community.

Many states, like Massachusetts and New York, already have incentives for energy efficient homes. In Pennsylvania, 7 Phius certified projects, representing over 350 units of affordable housing, have been built and shown to be cost-effective. Incentives in Massachusetts have led to the construction of 8 Phius low-income projects with almost 550 units. These projects have come in at between 1.5% and 2.8% above building code. Massachusetts, building on this success, just passed a progressive energy bill that will push it’s already progressive buildings sector forward.

The change is possible and we all deserve it, including those who never even seem to get a piece of the pie.

PHIUS+ 2021 Source Energy Factor for Grid Electricity

PHIUS+ 2021 will include a change to the source energy calculation for grid electricity to more accurately reflect future grid conditions and better weigh the impact of electricity versus natural gas use on site.

In past versions of PHIUS+, the source energy factor for grid electricity was defined by the Energy Star Portfolio Manager and was determined based on past generation and consumption data from the EIA. The calculation methodology accounts for the total primary fuel needed to deliver heat and electricity to the site, including conversion losses at the plant as well as transmission and distribution losses incurred to deliver electricity to the building. Under PHIUS+ 2018, the source energy factor for grid electricity for the U.S. was 2.80, which was an average of the EIA reported data from 2012-2016.

With the release of  PHIUS+ 2021 the calculated factor for the United States grid electricity is 1.73 which reflects a 2050 outlook. 

Figure 1: U.S. power sector evolution over time for the NREL Mid-case scenario

Figure 1: U.S. power sector evolution over time for the NREL Mid-case scenario

Calculating a future source energy factor for the United States electric grid electricity required the combination of three data sets: 

(1) The projected future electricity generation mix, which was taken from NREL’s Mid-Case Scenario for 2050.

(2) Fuel conversion energy factors per generation type from the EIA.

(3) Total system losses from transmission, distribution and storage, taken from eGRID2018 and NREL’s future grid mix scenario.

A detailed description of the calculation methodology and corresponding data sources can be found in the PHIUS Tech Corner article. Read the full article here.

 

EPA Indoor airPLUS and Radon Resistant Construction

0Today’s guest blogger is Tony Lisanti, PHIUS+ QA/QC manager. 

One of the prerequisite programs required for PHIUS+ Certification is the EPA’s Indoor airPLUS Program.  Born out of a need to minimize indoor air pollutants, the EPA dove-tailed this program with the ENERGY STAR Labeled Homes Program, which is also a prerequisite for the home or dwelling unit to earn both Indoor airPLUS and PHIUS+.  This serves to ensure that the dwelling unit is relatively tight, insulation is properly installed, the HVAC systems are properly sized, and bulk moisture throughout the building assembly is properly controlled.

Indoor airPLUS then takes indoor air quality to the next level. Integrating the Construction Specifications and Checklist requirements into the design, homes/dwelling units can then be verified to ensure greater precautions are taken for moisture control and dehumidification, air intakes are protected from birds and rodents, HVAC systems are kept clean, better filter media is used, and potential sources of moisture and contaminants are vented to the outdoors. Additionally, HVAC systems and ducts are prohibited in garages, pollutants from combustion equipment are minimized, and low VOC products are used.

One of the unique and important aspects of Indoor airPLUS is the requirement for radon-resistant construction measures in EPA Radon Zone 1. If you are not familiar with the Radon Zone map, it can be found here:  https://www.epa.gov/radon/epa-map-radon-zones.

Radon is a naturally occurring radioactive gas that can cause lung cancer. In fact, the EPA estimates that 21,000 deaths each year in the U.S. are attributable to radon exposure. The EPA has very good resources to read up on the health risks of radon. Their site can be found here: https://www.epa.gov/radon/health-risk-radon#head.

So why should PHIUS stakeholders be concerned with this? As mentioned above, PHIUS relies heavily on prerequisite programs such as ENERGY STAR and Indoor airPLUS. Since the airtightness standards for PHIUS Certified projects are up to 10 times more stringent than a typical code-built home, dilution of the indoor air cannot occur as readily. PHIUS ventilation requirements go well beyond those of systems found in typical Code built or even Energy Star Labeled homes. Good ventilation design, whether for code or for PHIUS starts with source control, i.e. minimizing the source of contaminants along with proper ventilation.

An example of a passive radon system.

An example of a passive radon system.

In high risk areas such as Radon Zone 1, EPA Indoor airPLUS requires installation of a passive radon system, at minimum. EPA also recommends utilizing active radon systems to further reduce radon concentrations in the home, although this is not yet an Indoor airPLUS requirement. The most modern radon standards are developed through an ANSI-accredited consensus process by the AARST Consortium (American Association of Radon Scientists and Technologists). EPA recommends following the ANSI/AARST CCAH Standard for 1-2 family dwellings and townhouses (max. total foundation area of 2500 sq. ft.) or the ANSI/AARST CC-1000 Standard for larger foundations, which often apply in multifamily buildings. However, the key components of a passive radon system for the purposes of Indoor airPLUS verification are succinctly outlined in Item 2.1 of their Construction Specifications.

ANSI/AARST will soon publish updated standards to provide guidance for the design and installation of two radon system options in new low-rise residential buildings. These systems, passive and powered, are designed to reduce elevated indoor radon levels by inducing a negative pressure in the soil below the building. The practice provides design and installation methods through soil depressurization systems that can be installed in in any geographic area.

Each of the two options consists of soil gas collection and a pipe distribution system to exhaust these gases. The first standard is for the design of passive radon reduction systems, sometimes referred to as a “radon rough-in” (ANSI/AARST RRNC). The second newly updated standard (anticipated in early 2020) includes details for a fan-powered radon reduction system, as well as radon testing (ANSI/AARST CCAH). Passive systems can result in reduced radon levels of up to 50%. These standards suggest that when radon test results for a building with a passive system are not acceptable, the system be converted to fan-powered operation. Typically, the action level is 4 pCi/L (Picocuries per liter). If the tested radon level exceeds 4pCI/L, then a fan is added to further depressurize the soil and positively vent the gas to the outside.

Recently, the EPA Indoor airPLUS team sent out this Technical Bulletin. The Technical Bulletin provides simple guidance on the installation of passive and active radon systems. Please pay particular attention to the drawings in the Bulletin, and note that the active system depicted has the fan located in a vented attic. This is outside the pressure/thermal boundary of the home. This has special significance with homes/buildings constructed to PHIUS Standards, because often, the attic space is WITHIN the pressure/thermal boundary of the home. Therefore, the fan cannot be located in the attic and must be outside the pressure/thermal boundary. The reason for this is, should there be a failure on the discharge or pressurized side of the fan, the building can actually be filled with radon gas.

Some other precautions that include a tight seal at the slab and vapor barrier to the vertical riser. Additionally, ensuring the riser is clearly labeled as “RADON” to minimize the chance that a plumbing waste line will be accidentally connected to it in the future is also important.

Tony Lisanti CEM, CPHC
PHIUS+ QA/QC Manager

With thanks to Nicholas Hurst from the EPA Indoor airPLUS Team

Policy Update: The Massachusetts Stretch

isaac pic

Isaac Elnecave, a member of the PHIUS certification team, has written this update on the Massachusetts stretch cove, the latest installment of his policy updates.

Over the last 8 years, Massachusetts has made significant progress towards making the passive house (PHIUS+) standard an integral part of its building energy code. This effort points the way to the end goal of creating a cost-effective net-zero energy code.

Besides its statewide base energy code, which is an amended version of the latest International Energy Conservation Code (IECC) model code, the Board of Building Regulations and Standards (BBRS) in Massachusetts has, since 2009, promulgated a “stretch” energy code. The base energy code governs the minimum energy saving requirements in buildings throughout the state. The requirements include: the amount of insulation required in ceilings, walls and foundations; window performance; the level of air tightness; ventilation requirements; the efficacy of lighting and the efficiency of HVAC equipment. It is often described as the worst possible building (from an energy perspective) that can legally be built.

A stretch energy code incorporates similar measures and design approaches but mandates energy efficiency requirements that result in higher performance buildings than those meeting the base energy code. While the base energy code is the default requirement across all towns and cities in the Commonwealth, the stretch energy code must be affirmatively adopted by local municipalities that want to enforce it (at which point, it supplements and overrides the base energy code in that jurisdiction). Importantly, unlike New York State, because the BBRS approves the stretch code, municipalities that adopt it cannot amend it.

In both the Base and Stretch codes in Massachusetts, there is a section for alternative compliance strategies, which specifically includes passive house in both the low-rise residential energy code chapter and the commercial energy code chapter. Under the requirements of its current edition, and in fact since 2012, in any jurisdiction that adopts the stretch code in Massachusetts, a PHIUS+ certified passive house automatically meets code. The current code amendments specify that the annual heating demand for PHIUS certified home or commercial building must be less than 10 kbtu/ft2/year; a value easily met by all certified PHIUS buildings.

The latest edition of the Massachusetts stretch code has just been adopted but has not yet been promulgated* — the expected promulgation date is February 8, 2020 with an effective date of Aug 8, 2020. There will be two significant changes. First, PHIUS itself has updated its standard to PHIUS + 2018 from PHIUS + 2015. Second, with this new edition, a residential or commercial building will be code compliant when it passes the pre-certification stage (much like saying a typical house is given code approval once the plans have been approved.) The updated energy code, based on the IECC 2018, shifts the passive house compliance option from the 10 kBtu/ft2/year metric to an option to seek PHIUS precertification prior to pulling a permit. A project must demonstrate that it has been submitted for final certification by PHIUS to receive the certificate of occupancy. Because PHIUS maintains a rigorous review process through the end of construction, this approach ensures a high quality of construction.

Passive house certification requirements are significantly more stringent than even the other alternative paths in the stretch code (the most commonly used path in the Massachusetts residential stretch code allows for an Energy Rating Index score of 55, which is well above the score typically achieved by a certified passive house).

Massachusetts provides an excellent example of how to use incentives to spur the development of high-performance buildings. Mass Save®, the statewide energy efficiency program in Massachusetts, launched a mid- to high-rise passive house incentive program in the summer of 2019. In the first 6 months over 40 projects with over 3,000 passive house units in development have signed up for the program.  As more projects are built meeting PHIUS standards either through the stretch code or through Mass Save, the universe of designers and builders who become proficient in the construction of high-performance builders grows. This proficiency will result in greater confidence among construction professionals and lower costs with respect to high performance buildings.

As the PHIUS standard includes a pathway to net-zero construction, including it in the stretch and base energy code provides a path for future improvements. In Massachusetts, stretch code development will now focus on a ‘net-zero’ code to run alongside an amended IECC 2021 base code. Having the passive house pathway in the energy codes has introduced designers and builders to the tools and techniques necessary for building cost-effective net-zero single-family and multi-family dwelling. PHIUS looks forward to working with Massachusetts Department of Energy Resources, BBRS and other key stakeholders in making a net-zero code a reality.

Massachusetts in one of three states and one municipality that have incorporated the PHIUS standard in the energy code. New York was discussed in a previous blog (Policy Update: New York State, Two Steps Forward, One Step Back, January 16, 2020). I’ll discuss efforts in Washington State and the city of Denver in a future post.

* Adoption means voting and signing by government official. Promulgation (it specifically means the decree that puts a law into effect), in practice, refers to when the agency in charge of enforcing the law signs off on the rules and regulations relating to the law.