Chicago Regulation Change Provides Opportunity for Phius Professionals

Al Mitchell

Al Mitchell

Phius Technical Staff Member Al Mitchell wrote this week’s blog post, which discusses the recent change in regulations related to coach houses in Chicago, and how designing these new buildings to Phius standards is a win-win for all parties.

The City of Chicago has lifted a nearly half-century ban on accessory dwelling units (ADUs), opening up a door for some people to build additional units on their property. The pilot program for ADU construction pertains to rentable units, occupiable by relatives, tenants, or even to be used as additional space from the primary home. There are two types of ADUs acknowledged by this regulation: a detached dwelling unit, such as a coach house or apartment on top of the garage, or a conversion unit, such as a built-out attic or basement.

However, there are a handful of caveats to consider. First, the allowances for ADUs, whether coach houses or conversion units, are limited to select pilot zones. There are five pilot zones: North, Northwest, West, South, and Southeast. These zones cover portions of 25 of the 77 Chicago community areas. Each area has a few special requirements for different types of ADU. For example, the North and Northwest zones can have a coach house built on the property before a primary house is built, while the other three zones require a primary house to be built on the lot before a coach house can be built. In the West, South, and Southwest zones, buildings must be owner-occupied in order to add a conversion unit. All ADUs in Chicago are to be rented for a minimum period of 1 month, and there is a requirement for a certain number of affordable units on larger properties where more units can be added.

 

Blog Pic 1This offers a great opportunity for people to add value to their property, create flexible living spaces (especially to take advantage of the benefits of multi-generational housing) or build a unit that can provide additional income for the owner while providing right-sized, cost-effective housing for another person. Approximately 70% of the lots in Chicago are 25 feet wide and face broadside south, making the applicability of this format broad. The aim of this blog is to make the case for building these newly allowed accessory dwelling units following the Phius passive building standards to create comfortable spaces, save energy and operational costs, and provide spaces that can weather inclement weather conditions, especially during a failure of space conditioning.

Analysis

Conversion units like the ones proposed in Chicago, would likely require a complete building retrofit to achieve the maximum cost and energy saving potential. This study is going to focus on detached coach houses, of maximum permitted dimensions. This comes at an apt time for Phius, as 2021 has marked the release of a user-friendly and streamlined prescriptive compliance path, as well as the performance target curves have been reworked to include allowances for small living spaces (in response to the tiny home craze).

Looking at coach house potentials, four cases were selected for evaluation. Three of the cases represent a single-story unit, one in the place of the garage, one pushed forward with open parking on the alley, and one built on top of the garage. The fourth case is a two-story coach house with no garage. The smaller units are studios, with no bedroom considered, one occupant, and the two-story coach house has one bedroom and two occupants. The standard kit of appliances is a dishwasher, refrigerator, and an induction range. Electric resistance water heaters are used in the base cases and a split heat pump system provides space conditioning.

The base cases follow code minimum constructions and windows per IECC 2018.  An envelope airtightness of 0.31 CFM50/sqft was used to match typical construction. The Phius CORE Prescriptive Path follows the prescriptive requirements per Chicago – Midway airport, and uses the default airtightness of 0.04 CFM50/sqft. The prescriptive path windows are whole window U-Values, and are set based on the required prescriptive comfort standards. Per the water heater efficiency requirements, the water heater was upgraded to a small heat pump water heater. The performance path uses 0.06 CFM50/sqft as the required airtightness metric, and follows the same window set as the prescriptive path. A heat pump water heater was used.  The other opaque assemblies were backed off from the conservative prescriptive path to meet the required calculated targets. Please reference the table below for the envelope performance specs in the study.

 

Case Wall R Roof R Slab R Window-U Airtightness CFM50/sf
IECC 2018 18.4 44.0 10.6 0.3 0.31
Phius 2021 CORE Prescriptive 40.0 71.0 21.6 0.16 0.04
Phius 2021 CORE 26.8 52.0 17.2 0.16 0.06
Blog Pic 2

 

Conclusion

The cases designed to Phius standards prove to reduce the space conditioning loads significantly, as shown in the Space Conditioning Results Chart. These outputs are specific per area, making it easy to compare different building sizes. Per the Source Energy Chart, the Prescriptive and Performance averages save 35% and 30% respectively. These source energy savings directly reflect the anticipated savings on an electrical power bill for the tenant of these coach houses.

Coach houses built to these passive building guidelines project significant energy savings that will directly benefit the occupants of these buildings, on top of the other comfort and passive survivability (what happens during a power failure – stay tuned for a part two blog). The required upgrades to meet the performance path is principally based around better windows and airtightness, saving on other insulation requirements per the prescriptive path. 

Blog Pic 3

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.

Breakthrough Project Aims to Bring Flood of Zero-Energy Housing to Milwaukee

 

 

Shilpa 12Shilpa Sankaran is a consultant driving adoption of innovations in the built environment and the health of the planet, societies, and people. She is currently an advisor to the City of Milwaukee, who is spearheading a breakthrough public-private partnership in offsite affordable, zero-energy housing production. Previously, Shilpa was the Executive Director of the Net Zero Energy Coalition, co-founder of the REALIZE prefabricated zero energy retrofit model, and co-founder of ZETA Communities, a modular zero energy buildings fabricator in Sacramento.

In the wake of a global crisis, a cocktail of pandemic, economic distress, political turmoil, and heightened awareness of social inequity, we sit in the still point of opportunity for change.

Cue the City of Milwaukee. This city has seen its share of change — including economic and social trauma from the depletion of its manufacturing culture — and it has shown amazing resilience through grit and innovation. Now, we see revitalized and thriving new neighborhoods, innovation in water and sustainability, and new industries popping up throughout the city.

MilwaukeeMilwaukee, led by Mayor Tom Barrett and the City’s Environmental Collaboration Office (ECO), is spearheading a project that could bring back the original spirit of the city, and serve as a model for other cities around the country. The City is seeking a partner to locate a factory that will build zero-energy housing as part of public-private social enterprise.

On the surface, this may sound like just another construction solution, but Milwaukee sees it as so much more. This one solution will create income opportunities and green skills development for the residents of one of the most economically depressed areas in the country. These very residents will also have new home ownership opportunities, and will be able to proudly support their own health and the health of the planet with zero energy homes. Local manufacturing will take place in this same area — the 30th Street corridor — restoring a culture of industry, while revitalizing the neighborhood.

The goal is to target Phius Certification for all buildings, which requires certification under EPA ENERGY STAR, DOE Zero Energy Ready Homes and EPA Indoor airPLUS as co-requisite programs.

To attract an aligned partner, the City of Milwaukee is deeply committed to lowering barriers to entry and supporting the long-term success of a factory partner with financial, training, pipeline, and policy and codes support.

The first step is garnering industry interest through a Request for Information (RFI) which is due on July 12th. Later this summer, a Request For Proposal (RFP) will be issued, and the hope is to secure a partnership by the end of 2021 or early 2022. Following the design and construction of demonstration unit(s), the goal is to open the factory for full production by 2023.

If you are interested in participating in this process, please submit your Intent to Respond, and respond to the short RFI by July 12th. The RFI can be found here.

On International Climate-Specific Passive Projects

Andres-vert3Phius Certification Team Member Andres Pinzon, PhD, explores the process of passive projects being built outside of the United States.

“Qué es una casa pasiva?” reads the cover of the drawing set of the Merlot House, a project submitted by CPHC Ignacio López pursuing PHIUS+ 2018 certification in Baja California-Mexico. This project — the first in this country — adds to the growing interest of Phius certification across latitudes.

During a regular week at Phius, we move between reviews on different climate zones, building functions and building types, assessing data from residential and non-residential, new construction, or retrofit. 

At first sight, the path toward certification may look intimidating, and we at Phius know that. Our team offers guidance and support for project submitters, especially when working on their first projects (overseas or not). The reviewers go above and beyond in helping project teams meet the specific, wide-ranged, and performance-driven goals of their buildings. This process offers achievable steps for certification within the context of each project.

How does Phius do it? The process includes: rounds of review, real-time feedback, conference calls, online open resources, etc. Phius tailors this process by providing solutions in compliance with certification, looking for red flags, and pointing out paths to avoid. This allows us to work with clients, architects, engineers, building scientists, etc. on the critical aspects of certifying a project in a particular part of the world.

Here are some remarks from our experience working with projects submitted to Phius outside of the mainstream of US and Canada.

The first step is generally custom climate data, followed by calculating the project-specific performance targets. Using the appropriate climate data and performance targets are essential to accurately modeling and reducing energy loads. Phius generates custom climate datasets for project teams that accurately represent their current project’s location. For most locations, we have not had trouble finding a TMY3 station within a (80-km) 50-mile range.  

In addition to climate data, marginal costs of electricity ($/kWh) at the regional/national level are needed to calculate the custom space conditioning targets they will use for certification. With this, teams can begin to work on comprehensive design and energy modeling; aware of the demands and loads that are expected for their buildings. 

Phius has projects in places such as Japan, Colombia, Nigeria and Mexico, where Phius certification represents a third-party verification on a desired performance for energy use and high-quality housing (see post on Housing Equity). The accumulated experience of different situations helps Phius come up with new solutions for diverse challenges and pass that knowledge to teams in subsequent projects.  

For example, approaches on cooling and dehumidification seen in Phius projects in southern states can guide us on how to tackle larger demands and peak loads in projects in tropical areas of South America or Africa. We see this potential in aspects such as: the enclosure’s insulation and airtightness, shading dimensioning and optimization to avoid overheating, and the proper selection and sizing of mechanical devices.  

Energy and carbon saving targets in buildings and operational budgets are a global concern. However, some information might be lost in translation when moving between countries, languages, cultures, or systems of measurement. In this sense, Phius is working on expanding the limits on a technical language that might hinder the domain of Phius projects.

Phius’ CPHC training is also offered and taught in SI units. In this way, professionals abroad who are interested in earning this credential can have access to material on building science principles, design exercises, and software tutorials prepared in the metric system. Furthermore, WUFI® Passive, the energy modeling software used for Phius certification, allows users to easily toggle between SI and IP units any time during the process.

More actions are in development within the idea of expanding the Phius community abroad. It is exciting to see creative and innovative approaches, integrating different sorts of information to make a high-performance building, such as the “bilingual” drawing set from the Merlot house. I cannot wait to attend the breakout session on international climate-specific passive projects at PhiusCon 2021 to continue the conversation.

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.