PDT and Passivehaus_ME Annual Meeting + passivSLAM!

Architects and Passive House affiliates from Connecticut, Massachusetts, and Maine gathered at the Friends School of Portland for the annual meeting in April. PDT Architects has joined Passivehaus Maine to help expand sustainable building practices and work towards net-zero buildings in New England. Architect Keegan Carmichael attended the meeting.

Friends School Tour:
Since the Friends School has moved to their new building, enrollment has drastically increased. The wall assembly is composed of a 2x6 dense-packed cellulose wood stud with 4” of exterior rigid insulation on strapping and a metal siding. Due to the restriction of passive house air sealing needs, the school does not have a commercial kitchen. The school wanted the most energy efficient building possible, and small tweaks in the building systems allowed for significantly reduced energy bills. Heat pumps run almost 24 hours a day to help regulate the interior temperature. With small amounts of energy used to regulate the temperature, the school avoids peak demand charges and has less stress on the units. Solar panels on the roof pour electricity back into the grid and help with the school’s goal of being net-zero energy.


Viridescent House Tour:
Due to zoning codes, the Viridescent House currently operates as an office but can be converted back into a house. The office is equipped with a shower and full kitchen, with a south-facing wall that illuminates the open office space and atrium. The building assembly is wood I-joists with dense-packed cellulose fastened onto 2x6 wood studs which sit on a slab on grade on top of 8” of extruded polystyrene. Tidesmart, the client, wanted an extremely efficient building, and with the combination of an airtight super-insulated building and solar panels, the Viridescent House produces twice as much energy as it consumes.


Waldorf School Tour:

The new school building currently under construction in Freeport will house educational programs and expand the campus. The building envelope is an 8” wood stud with dense-packed cellulose and 4” of mineral wool. Oriented for a passive solar design, the structure will use ductless mini splits for air conditioning. Every classroom has a sink for program flexibility. The new building, with the aid of passive house strategies, is pursuing Maine advanced building certification.

PDT Architects visits maker spaces in RI with Caribou Middle School

Here is Leland Caron, principal of Caribou Middle School, at AS220 in Providence last week as part of our tour of maker spaces, innovation centers, and project -based learning environments. We spent the better part of two days visiting schools and talking to educators as we begin to design RSU 39's new innovation center.


Jane McCall, assistant superintendent of curriculum and instruction at RSU 39; Leland Caron; Alan Kuniholm and Chelsea Lipham of PDT Architects; and Adam Tilove, head of the Jewish Community Day School of Rhode Island, visited the Rhode Island School of Design, Moses Brown School, Brown University, Wheeler School, AS220, and Berwick Academy, where they visited maker spaces, innovation spaces, and project-based learning environments.


Current designs for the new pre-K-8 school in Caribou call for a maker space in the heart of the school, where students will learn to define problems, collaborate on solutions, choose materials, and gain skills in many different disciplines.


--Alan Kuniholm

PDT at P.A.T.H.S. with ACE mentors

Portland Masonry Company hosted a demonstration at PATHS (Portland Arts and Technical High School) for ACE students GIVE DATE HERE. PDT’s Adam McKinnon, Alyssa Phanitdasack, and Keegan Carmichael attended the bricklaying demonstration by master mason Ed McGarrity. Students learned the fundamentals of masonry as well as a brief history of decorative styles that are prevalent in the Old Port. PATHS offers courses in building trades with a hands-on approach to learning. A list of programs offered at PATHS can be found in the link below.


62 Spring Street Approved for Low Income Tax Credits

62 Spring Street Approved for Low Income Tax Credits

“We’re thrilled that this project is going ahead,” said Ethan Boxer-Macomber of Anew and Brian Curley of PDT Architects, “and we’re delighted to be partnering with Auburn Housing to provide much-needed family housing in the heart of Auburn.”

PDT volunteers with the ACE Mentor program

PDT volunteers with the ACE Mentor program

Alyssa Phanitdasack, Matt Pitzer, Keegan Carmichael, and Adam McKinnon of PDT Architects are volunteering with the ACE Mentor Program, an after-school program for high school students interested in the architecture, construction, and engineering fields.

Complex floor at Freeport High School

Here’s the cast-in-place concrete floor being poured at the lower level of the Freeport High School addition. Workers are leveling the freshly placed concrete and performing various finishing activities.

What might seem like a simple floor system actually has many components that work together. The yellow material being covered in concrete is the under-slab vapor retarder that keeps moisture in the soil from entering the finished slab. A layer of extruded polystyrene insulation is hidden underneath the vapor retarder. Orange radiant heat tubes, attached to a layer of welded wire mesh and embedded in the concrete, will provide a comfortable and efficient source of heat for new rooms on the building’s perimeter. Blog post by Bob Curtis.

Photographing the Capital Judicial Center #1

Beautiful September Saturday morning, early, walking out over the Kennebec on the pedestrian walkway of Augusta’s Memorial Bridge. The bridge isn’t vibrating nearly as scarily as it had during the scouting trips. There’s a barrier between us and the cars and trucks, which is good because they’re whizzing by only a few feet away. I’ve explained to Sandy, the photographer, and Justin, her assistant, that we don’t have to use a ladder to shoot over the chainlink fence, and we don’t have to shoot through the holes. We can just shoot under the fence.

What is a Green School?


PDT recently led green schools presentations for each of our two newest school clients, RSU 39 in Caribou and MSAD 75 in Topsham. The presentations were educational, inspirational, participatory, and the beginning of our green schools goal setting process for each of the projects.

What is a Green School?

A green school is healthy, comfortable, energy efficient, material efficient, and easy to maintain and operate. A green school is located on an environmentally responsible site, is adaptable to changing needs, is safe and secure, and is a building that teaches. The design, construction, and operations of a green school are based on long term, life cycle costs that result in minimized environmental impact, improved occupant health and productivity, and reduced long term operational costs.

Benefits of a green school

Benefits of a green school

How do we design a green school?… With an integrative design process.

An integrative process encourages project teams to identify shared goals early in the design process, analyze synergies between all parts of the project, and explore multiple strategies to meet project performance goals. The process embeds the value and meaning of sustainability into how we work on our projects.

What this means for our work in simple terms is that we frontload the design process. • We holistically understand the existing context. • We set shared goals with the owner prior to design. • We bring all team members to the table early in the design process. • Applying systems thinking, we set up feedback loops and other collaborative procedures to optimize all the decisions we make.

We will take the conversations from each of the green schools presentations and begin to prioritize unique sustainability goals for each project. We will carry those goals throughout each project - weighing our options, considering life cycle costs, looking at synergies between systems, and making sure both clients end up with a cost effective, healthy, and environmentally friendly building that can truly enhance productivity and make education enjoyable and rewarding.

Green Education at the Courthouse

energy savings
energy savings

The Capital Judicial Center in Augusta, Maine, designed by PDT Architects, opened in March. The 4-story 120,000-sf courthouse combines superior and district courts with other court functions on a steeply sloping site adjacent to the historic Kennebec County Courthouse, to which it is linked by a second-floor bridge. The design observes ideal courthouse planning principles, with separate, secure circulation for staff, detainees, and the judiciary.

The project is targeting LEED Silver certification. High efficiency zone heating and cooling is provided by chilled beams and radiant floor heating. One of the most stunning features is the natural daylight that pours into the public lobby and corridors as well as into the courtrooms and workspaces.

Green Education

In addition to the building itself, a comprehensive green education program will be installed in the courthouse later this summer. Green education signage will be installed into the building's spaces to educate the occupants and visitors of the green building features of the courthouse. The signage will be installed in both the public and secure staff areas. Rack cards summarizing the sustainable features of the building will be available in the first floor public lobby and sustainable living facts will be on the digital displays throughout the building. For a preview of the signage, see below.

Green Education1-sml
Green Education2b-sml
Green Education3-sml

Passive House Not Only For Homes

On March 16th, Günter Lang, Austrian passivhaus expert, gave a presentation on the Passive House building standard. The term Passive House refers to a rigorous, voluntary standard for energy efficiency in a building. A project that follows Passive House principles results in an ultra-low energy building that requires little energy for space heating or cooling. Thermal comfort is achieved to a maximum extent through passive measures (insulation, heat recovery, passive use of solar energy and internal heat sources). Günter Lang’s presentation demonstrated the great potential and versatility of the Passive House standard not only for single family residences which are most commonly associated with the standard, but also for apartment buildings, affordable housing, schools, courthouses, healthcare, office buildings, retrofits and entire city districts. Sponsored by passivhausMAINE and AIA Maine, the talk referenced a variety of large scale building types and a variety of construction types to show that there are many ways of building a Passive House building.

Some Firsts and Largests

RHW Tower

First Passive House Skyscraper The corporate headquarters of Austrian Raiffeisen-Holding in Vienna, rising 240 feet, only 60 feet wide, and with a glazed double-skin façade, exceeds our previous perceptions of what a Passive House looks like, and for the first time a skyscraper was designed and built (by Atelier Hayde Architekten and Architekt Maurer) to meet Passive House standards.

Three main factors allow the building to meet the Passive House standard:

  • Thermal efficiency of the well-insulated double facade
  • Use of daylight to reduce electrical lighting requirements
  • Advanced mechanical systems

The World’s Largest Passive House district Heidelberg’s Bahnstadt is the world’s largest Passive House district. Bahnstadt is a model for how Passive House can become the standard for large scale developments, districts and entire cities.

Heidelberg’s newest city district, Bahnstadt is being built completely to the Passive House Standard. The basis for this is an integrated energy concept that was developed and passed by the Heidelberg City Council alongside urban development and other key concepts necessary for such a scheme. The Passive House Standard is legally binding through contracts and was set via a development law mechanism. Additionally, compliance with the Passive House Standard has been integrated into the building permit process.  Special energy consulting and financial aid is available for builders and developers.  Currently, the first segment of residential building is mostly finished, already offering living space for some 1,500 people. The entire residential part of the project is currently two years ahead of schedule due to the high demand. In addition to living space and a kindergarten, the district will also offer Passive House cafes, restaurants, office space, a laboratory, a supermarket, a movie theatre, and a building supply store. (Passive House Institute press release, 30.06.2014 )

LifeCycle Tower

Prefabricated Wood High-Rise Construction (or An 8 Story Building Built In 8 Days)The LifeCycle Tower ONE in Dornbirn, Austria was completed in 2012 and is a PassiveHaus certified high rise constructed with prefabricated wood and reinforced masonry components. Prefabrication allowed for the 8 story building to be assembled on-site in 8 days. LifeCycle Tower TWO, the Illwerke Montafon Center in Montafon, Austria, of the same construction type, was also completed in 2012. The Illwerke Montafon Center is 5 stories tall, with a basement, and has approximately 100,000 sf of floor space. These buildings demonstrate how passive house standards can be applied to both mid- and high-rise wood construction and prefabricated modules.

Simple buildings with simple systems

Wood towers and Passive House skyscrapers will be seen more and more in the future. The double facade will be used more often around the world. A precedent has been set for pre-manufactured Passive House buildings that can be used for temporary housing and then relocated to different sites as necessary. Gunter Lang emphasized that the Passive House standard can successfully be incorporated into any building design (everything emits energy!) and implemented into local policies and codes as well.

  • Design simple buildings with simple systems.
  • Design buildings that passively use the sun, water, earth and air as much as advanced building systems.
  • Design with energy use reduction and a high performance envelope in mind.
  • Be a good advocate. Most buildings built now will need to exist in the future without reliance on fossil fuels so design for that now.

Passive House Case Study Resources

Passive House Database (you can even add your own Passive House project to the database!)

Passive House Regions (PassREg)

Passive House 2014 Awards

International Passive House Association (iPHA)

Healthy Materials

Pam Anderson, Joan Klein, Suzanne Morin, and Allison Zuchman of PDT attended the Healthy Materials Summit in Boston in November. The Healthy Materials Summit, the first to be held in New England, was a giant leap in broadening the dialogue about making a greater positive impact when choosing building materials and products. By requiring full disclosure and transparency of material composition for each product that goes into our buildings, we can challenge manufacturers, designers, specifiers, and end-users to make informed decisions not only about the environmental qualities of materials but also about how materials we choose impact human health and comfort. At the Summit, industry leaders Nadav Malin (BuildingGreen), Bill Walsh (Healthy Buildings Network), Denis Darragh (Forbo Flooring Systems), Tracey Powel (ASSA ABLOY), Heather Henriksen (Harvard Office for Sustainability), and Melissa McCullough (Environmental Health & Safety, Dana-Farber Cancer Institute) spoke about where the market is now, the opportunities and challenges around driving the marketplace toward health product declarations, and the branding of their own organizations around material transparency and sustainability.

Twenty years ago the industry started promoting green materials. That translated into a myriad of products with varying degrees of recycled and regional content. Toxins were addressed most commonly with low- or no-VOC products. Today a more holistic approach is needed to also address life-cycle costs and the health impact of materials. EPD’s (environmental product declarations) and HPD’s (health product declarations) are two tools being adopted by the industry that move us in that direction.


An EPD is a summary of the environmental characteristics of a product based on its life-cycle assessment. The life-cycle assessment is based on information from sourcing and transportation of raw materials, to product installation, durability and maintenance, all the way to repurposing, recycling or disposing of the material at the end of its life.

A health product declaration (HPD), the focus of the Summit, is a nutrition label for a building product. A HPD reports a product’s contents and each ingredient’s relationship to the bigger picture of human and ecological health. A HPD increases transparency by disclosing ingredients and their potential health hazards and reduces redundancy by referencing existing hazard lists, EPD’s and other information that is available industry-wide. Unlike the EPD, the HPD has a standard, fixed reporting format which creates consistency, makes clear which information is reported and which is not, and is free to use.

For more information see the following resources: Health Product Declaration Collaborative Perkins+Will Transparency List Pharos Declare

Hybrid Operating Room

Design was recently completed for a new 1,250-sf hybrid operating room and adjoining control room. A hybrid OR merges the surgical capability of a large-scale OR with the imaging advantages of a catheterization lab. It allows for less invasive, safer procedures, leading to an increase in positive outcomes and faster patient recovery. The hybrid operating room will incorporate the most current integrated operating room technologies. A modular ceiling diffuser system, which removes contaminants and provides HEPA-filtered air, will be hung directly above the patient table. An X-ray imaging system that moves freely in the treatment area will provide more room around the patient table and allow easy access to other equipment. An engineered modular ceiling and wall system with stainless steel clad surfaces will support flexibility and minimize downtime to adapt the room for continually changing needs.

Evidence-based design and a sustainable design approach will support the health and safety of both the patients and the caregivers.

Hybrid OR 3D Plan
Hybrid OR View

PDT's healthcare studio is also working on an ICU renovation, hospital imaging rooms, a surgery center master plan, an audiology center, and a neuroscience research facility that includes exam rooms, imaging and testing rooms, research offices and lab spaces.

Learn more about PDT's healthcare projects here.