Passive Design/Build Project Boost

Passive Design/Build™️ Project Boost

Formerly called ‘Preliminary Passive House Review’ (PPHR)

Learn more by watching our Overview Video. Fill out the form to receive a PDF of a sample Project Boost report, and see our YouTube channel for detailed walk-throughs of what to expect.

Why do you need an energy model for your project? (Hint: it’s NOT about certification.)

You simply cannot reach a goal that is undefined.

This is about understanding what you specifically need for your project to be comfortable, healthy, durable, and energy efficient, then setting metrics to that.

Real life example: A client spent a few thousand dollars with Emu on a Project Boost for a small project. We analyzed the early-stage concept design and found that the assumed window package was only one of 3 options that would have met the clients performance goals. The result was a savings of $27,000 by selecting a window package with verifiable performance specifications.

“It’s an exceptionally detailed and informative report and to be honest I’ve not seen a report of this calibre before.” – Anthony Jenkin, Outlier Studio

Boost - 3D Passive House energy model, developed in DesignPH and completed in PHPP
The energy modeling of the Boost is a full 3D Passive House energy model, developed in DesignPH and completed in PHPP. This delivers much more accurate results for Passive House and high performance buildings than other software.
Boost - accurate shading analysis
The modeling includes accurate shading analysis for each glazed area of the project, that includes the impact of surrounding objects such as terrain, neighboring buildings, as well as evergreen and deciduous vegetation. This accurate shading analysis is crucial to optimize the performance of the building in Summer as well as in Winter, and determine the low-e coating that the project needs to regulate the passive solar gain through windows and exterior doors.
Boost - strengths and weaknesses of the design
The feedback covered in the Boost includes big picture analysis of the building, and highlights strengths and weaknesses of the design. This informs the decision for 'how far to push' the project, to maximize cost-effective performance as well as prevent overkill.

Emu boosts projects all over North America

Our map of Project Boosts and Emu Pilot Projects shows all the places where we have analyzed projects for early-stage performance goal setting.

Want to learn more?

There are many prescriptive approaches in the market, that provide generic answers on how to build a ‘high performance’ building’

While simple answers are attractive, prescriptive approaches don’t address specific needs of a project.

An example of a prescriptive approach looks like: “in Climate Zone 5, you need 4-inch exterior insulation, triple glazed windows, and an HRV continuous ventilation”. An approach like that does not tell you how a product will perform by itself (do all triple glazed windows perform the same?), nor how it will perform in your project conditions (do you need an ERV or HRV?), nor how it will perform in combination with other products (what if I have 3-inch insulation and better windows?).

Basically, a prescriptive approach is when one knows the answers before being asked the question.

To draw an analogy, it’s like going to the doctor and they put your arm in a cast, without even knowing if it’s actually broken.

From a prescriptive checklist, you may get that you need better windows than what Code-minimum requires. What you don’t get is how the better window package performs in combination with the higher R-values, or the tighter air barrier, or both.

  • How comfortable is it going to be?
  • Do you need those extra good windows?
  • How much better is product 1 compared to product 2?
  • If I do A, can I avoid doing B?
  • If I beef up my building envelope, how much smaller does my heating and cooling system become?
  • How much less energy is the building going to consume?

Prescriptive checklists cannot answer this type of questions, because there’s nothing specific about your project in the way they are developed.

Unlike prescriptive checklists, a performance-based approach is based on identifying specific needs of a project, and using a science-based method to achieve them.

‘High Performance’ in buildings is often identified as energy efficiency alone. While energy efficiency is important, our motto is ‘buildings are for people’.

There are way to quantify the level of comfort in buildings, based on the Passive House science. We apply that to all projects we work on, whether or not they seek certification.

We use that to provide guidance to project teams, and help determine what minimum performance a project needs to achieve thermal comfort in the specific climate conditions of the site location.

Similarly, our specifications with regards to fresh air systems (ERV/HRV), heating/cooling systems, and other aspects of the project are based on what we determine from the energy model.

We use the Passive House science to determine what you need, why you need it, and how badly you need it.

In other words, the energy model is used as a science-based tool to support specific, informed decisions. It’s just like the doctor uses X-rays to determine if your arm is actually broken before putting it in a cast, or recommending something else.

Most people know that the international Passive House standard is recognized as the most stringent standard for energy efficiency in buildings.

What many don’t know is that Passive House contains performance metrics that make buildings much more comfortable, healthy, and durable than conventional buildings.

The goal of the Boost is to use the Passive House science to significantly improve the performance of the building, in terms of thermal comfort, indoor air quality, and energy efficiency.

Based on the results of the Boost, teams can make informed decisions for the next steps of their project, That allows to refine the design and its performance goals, and develop the project budget based on specific needs.

While the Boost is based on the full Passive House energy modeling of the project, it is not indented only for project seeking Passive House certification.

The Boost answers questions such as ‘how much insulation do we need?’, or ‘do I need the extra performance in the windows for my project?’.

The Passive House science provides the handrail to navigate the needs of the project, and provides guidance to avoid overkill as well as performance gap.

Ideally, the best time to run the analysis is the schematic design stage. That allows to make the most impactful improvements to the project, at a time where it is easiest and cheapest to do so.

The Boost includes:

  • review of the project design, including form factor, window to wall ratio, and solar access
  • thorough thermal comfort analysis for windows/doors, and specs to request to suppliers of windows/doors
  • specs for the fresh air ventilation system (ERV/HRV), including room-by-room airflow rates for indoor air quality (including recommendations for setup and commissioning of the system).
  • thorough shading analysis for Winter and Summer performance
  • overall energy efficiency for heating/cooling, and energy savings compared to building a Code-minimum building
  • benchmarking of the energy efficiency against Passive House and Low Energy Building standards
  • whole building heating and cooling loads, used to size up the heating/cooling system of the building.
Passive House Thermal Comfort Analysis

This graph shows the Boost science-based method to determining the required minimum performance for windows and doors to achieve thermal comfort. It is based on local climate conditions, the project-specific design, and thermal comfort requirements contained in the international Passive House standard.

This analysis is key in determining if a project needs the extra performance from the window package. It’s also a way to determine if a window product can deliver the necessary performance and ensure comfort.

Passive House Building Optimization - Heating + Cooling

Emu’s “Decision Matrix” shown here shows the project site energy demand for heating and cooling, for all scenarios modeled in the Boost.

The Decision Matrix is key in making informed decisions, and to compare the impact of different choices that the project faces.

For the project shown here, the variables considered in the Boost included:

  1. How Much To Insulate (i.e. ‘R-value Targeting)
  2. Thermal Performance Of Windows/Doors
  3. Level Of Air Tightness Of The Building (i.e. assumed air changes per hour, ACH50)

The Decision Matrix here shows:

  • energy consumption for heating + cooling for all combinations considered (e.g. ‘medium’ Passive House R-values plus B-grade windows plus Passive House-level air tightness)
  • reduction of energy consumption compared to building the same building just to Code-minimum compliance
  • kWh per year needed to offset the heating+cooling, e.g. to size the PV system and get to Net Zero

Why Choose Emu?

Passive House is what we do, day in and day out.

We have been specializing in Passive House since 2010, and have used the building science in literally hundreds of projects.

We have implemented Passive House in all climate zones of the US, from hot humid climates in the South, to super cold climates in the Rockies. We have extensive expertise with European high performance products (and we have supported manufacturers develop their products to meet Passive House).

Our past as project architects (that’s how Emu started!) helps provide guidance to teams at early design stages, and coordinating with other priorities of the project.

We are also used to translating building science metrics to solutions that work in the field, as we’ve been the main providers for Passive House builder training in the US for years.

Here you can see the map of Project Boosts and Pilot Projects we have worked on.

This is where you can find (most of) our projects in the International Passive House Database.


Watch The Boost On YouTube:

Hear what happy Emus have to say about our Passive House Reviews

“After honing in on an initial design, we decided to get expert input about the energy efficiency of the design. After much internet searching, we found Emu Systems, and hired them for their Preliminary Passive House Review. That put us on the path to enrolling in their Passive House pilot program. One of the recommendations of the preliminary report was to simplify the geometry and move the mechanical room to the center of the home. We also simplified the geometry and surface area of the windows. We ended up with a better design in the end.” – Matt Kirsch and Kerri Stroupe, Homeowners

“In a recent project, Emu’s Preliminary Passive House Review readily identified that code level windows were not only the weak link in the design solution but also could lead to discomfort and condensation problems and resoundingly convinced the owner of the value of high performance windows. It set us on a better course of action while it was still efficient to make revisions and long before it was too late to turnaround.” – Greg D. Fisher, Architect

Take the Next Step

Move forward with confidence on your project by reaching out to Emu today. Fill out the form below to receive more information on our PPHR and a sample report. Ready to start your review? Email your plans and concept design to for a faster estimate!