In order to achieve the Passive House standard, a project must clearly demonstrate that it meets stringent performance and quality assurance requirements. Local Impact Design’s responsibility is to help the architect and builder team achieve the necessary standards. Local Impact Design offers full spectrum engineering services for Passive House and high-performance buildings including energy modelling, mechanical HVAC design, building science, solar renewable, rainwater & greywater harvesting, and structural analysis.
As Passive House consultant on a project, our roles typically include:
Developing an energy model to simulate energy use is necessary to provide confidence that the critical performance thresholds will be met. It is also a required step for Passive House certification. The Passive House Institute (PHI) has developed a detailed modelling software called the Passivhaus Planning Package (PHPP) that must be completed and verified by PHI. We also use a Sketchup modelling tool called DesignPH – an iterative design tool that calculates heating and cooling loads based on areas, windows, solar & shading. It’s easy to change the building shape and size and insulation, with instant feedback on energy use, thereby saving significant time for decision making and modelling. We find that SketchUp is the best way to visualize a building also. We can even import your plot using Google Earth.
Because Passive House is still a new concept to builders, more design detailing is necessary to convey how the building is to be constructed, especially in critical areas such as air barrier and thermal bridges at connection points (slab/wall, wall/roof etc.). As they say, the Devil’s in the details. Specialized knowledge is also required for specification of windows, building shell (highly insulated exterior walls, roof and floor slab) and heat recovery ventilation units.
This is the building industry’s quality control process. Best practice commissioning pays for itself many times over by identifying design issues before they are built, avoiding change orders for re-work during construction. Commissioning also optimizes operation, typically squeezing out 5-10% additional savings, and even extends into problem-solving following occupancy. Commissioning activities include oversight for blower door testing (for air tightness) and MVHR system commissioning.
Passive House Certification
Our role as Passive House consultant on a project includes assembling all submittal requirements for Passive House certification, including energy model and backup product documentation needed to demonstrate that the energy performance standards established by the Passive House Institute have been satisfied.
Management of Integrated Design Process
The preceding tasks represent the minimum intervention required to achieve Passive House equivalence required for certification. But achieving Passive House’s high-performance levels requires more than just the application of technical know-how. Integrated Design is key to realising high performance and Passive House buildings. The efficiencies achieved in the team-based approach can eliminate up to 40 percent waste that is inherent in the traditional project delivery process. As a professionally-trained facilitator, Rob Blakeney’s strength is in focusing and integrating teams to realize improved energy and environmental performance while at the same time minimizing operational and bottom-line costs.
The ability to incorporate green strategies into a project is most easily accomplished early in the design stage where synergies are uncovered and deeply integrated into a project. While this may mean more early input from the design team, it pays off because thorough, holistic design adds value faster than it adds cost. Modelling using the Passive House Planning Package (PHPP) during early design meetings is useful for informing the design team about how decisions affect energy use and end-user comfort. Properly costing these design decisions is also crucial to ensure we get it right from the beginning because any efficiencies will be lost if the project needs to be redesigned to meet budget constraints later on.