Energy modeling studio

About passive house

About us

eMod Studio is a Certified Passive House Consultancy firm with a mission to provide a thorough feasibility analysis of your Passive House project.

We use PHPP or WUFI certification tools (accommodating your preference of the Passive House certification) for energy balance calculations, and perform thermal bridge analyses of critical structure assemblies. Our goal is to give you an assessment of whether your design/project would meet Passive House certification criteria. 

We collaborate with your architect and the rest of your team to provide guidance on how to evolve the design in order to reach the Passive House performance level. 

Passivhaus buildings provide a high level of occupant comfort while using very little energy for heating and cooling. They are built with meticulous attention to detail and rigorous design and construction according to principles developed by the Passivhaus Institute in Germany, and can be certified through an exacting quality assurance process.


The definition of Passivhaus is driven by air quality and comfort: "A Passivhaus is a building in which thermal comfort can be achieved solely by post-heating or post-cooling the fresh air flow required for a good indoor air quality, without the need for additional recirculation of air." - Passivhaus Institut (PHI)


PHI Performance targets

  • Space heating demand: ≤ 15 kWh/m2 yr  --  4.75 kBTU/(ft2 yr)
  • Alternative criteriea: Specific heating load ≤ 10 W/m2  --  3.17 BTU/(ft2hr)
  • Space cooling demand: ≤ 15 kWh/m2 yr  --  4.75 kBTU/(ft2 yr)
  • Alternative criteriea: Specific cooling load ≤ 10 W/m2  --  3.17 BTU/(ft2hr)
  • Renewable Primary energy (PER) [kWh/m2 yr]: ≤ 60 (Classic), 45 (Plus), 30 (Premium)
  • Airtightness: ≤ 0.6 air changes/hr @ n50

PHIUS Performance Targets

  • Source Energy, Residential ≤ 3840 kWh/person/yr; Occupancy  --  (# of bedrooms + 1), per unit
  • Source Energy, Non-Residential ≤ 34.8 kBTU/ft2iCFA/yr
  • Airtightness ≤ 0.060 CFM50/ft2 of gross enclosure area
  • Airtightness, MF ≥ 5 stories, non-comb.  ≤ 0.080 CFM50/ft2 of gross enclosure area
  • Annual Heating Demand / Annual Cooling Demand  --  Climate Specific kBTU/ft2iCFA/yr
  • Peak Heating Load / Peak Cooling Load  --  Climate Specific kBTU/ft2iCFA/yr

Energy balance modeling

Use PHPP or WUFI, depending on the Passive House standard you are seeking, to evaluate the feasibility of your design for Passive House certification.


Thermal bridge analysis

Use thermal modeling analysis to assess whether your design and construction detail provides for a continuous thermal barrier or some thermal bridges sneak through and allow energy losses.

gallery/15 park foundation-wall x-section 5 w cellulose
gallery/foundation and wall section - no studs and tjis - color infrared w legend

Passive House project - Foundation, wall and floor junction - in between studs (24" OC)

gallery/foundation and wall section - no studs and tjis - flux vectors zoomed
gallery/foundation and wall section - no studs and tjis - isotherms

Passive House project - Foundation, wall and floor junction - x-section on studs and TJIs (24" OC)

gallery/15 park foundation-wall x-section 3 w cellulose
gallery/foundation and wall section - color infrared w legend
gallery/foundation and wall section - constant flux vectors
gallery/foundation and wall section isotherms 2

Passive House project - French patio door, foundation and floor junction

gallery/15 park french door-foundation-wall-roof x-section 4
gallery/x-section patio door - temp color graph
gallery/x-section patio door - flux vectors 1
gallery/x-section patio door - isothermals 1

walk the talk

The first Certified Passive House Plus is our own home that we built with a local Design/Build firm Placetailor in 2012/13. It is a two storey, single-family home with ~1300 sqft of Treated Floor Area.


Foundation is a combination of a stem wall and a shallow ring beam, separated with mineral wool. Walls are double studs with ~14.5" of dense packed cellulose. There are 2 smart membranes in the envelope - outside is a SIGA Majvest membrane (with high PERM rating) and inside is SIGA Majpell 5 with a low PERM rating to reduce diffusivity into the wall. Membranes and windows are all taped with SIGA tapes. Windows are triple pane, tilt and turn, imported from Europe. Heating and cooling are done by a Mitsubishi mini-split. Hot water is supplied with a Solar Thermal system and the whole house is ventilated with an HRV.

For the last 7 years, the house is performing beautifully, and above expectations. With the addition of a small PV in 2016, we have been Net Positive!


Whole contruction process is illustrated on the Park Passivhaus Blog.

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