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Requirements

Construction quality has an important effect on running costs. Good airtightness and efficient ventilation heat recovery help for reducing the space heating demand, and thus running costs.

Energy performance
A Passive House’s heating power demand is very low, on normal winter days only 10 W/m2. The requirement to fulfil this goal is to reduce the building heat losses to a minimum. To accomplish the low heat losses, quality of design and construction needs to be high. A passive House’s thermal insulation level is well beyond typical buildings. As the concept yet is not widely adopted yet, and as there is lack of experience to build Passive Houses in most countries, guidance in all the procurement phases is needed, especially at the site.

Passive Houses can be heated using ventilation heating systems. This is also a relatively rare way of heating. Thus the building users need to be informed on the performance and limitations and control of the system. If the user’s expectations are different, the delivery may not fulfil their demand. Poor understanding of the systems and the concept may contribute to problems in use, and also increased energy consumption.

It is essential that the inhabitants are informed properly about the characters and important factors affecting energy use and indoor climate of a passive house. An informative meeting and a guide book to inhabitants is strongly encouraged.

Procurement
To achieve high standard of energy-efficiency for a building requires more effort in planning and design phases, and in construction compared to standard. Once experience increases, the effort reduces. Integrated design processes help for achieving the desired outcome. As the heating energy consumption and power demand are extremely low, even small defects in the design and construction may reduce the possibilities to reach the aim.

Continuous site checks and quality control are essential during the whole building process. In the building site both visual inspections and measurements should be carried out before inhabitants move in. Passive House certification scheme lays down the requirements for commissioning, where PHPP is mainly used as a design verification tool. The most important test is the air tightness test using the Blower door test.

The procurement process should fulfil user and owner requirements and Passive House performance requirements. These requirements should guide the whole design and construction process. The following steps are crucial for the outcome:

    • Pre-design phase
      • Commitment to Passive House concept
      • Spatial planning requirements for architectural design
      • Site characteristics, wind rose, ground conditions
      • Building type, materials and systems


    • Design
      • Utilization of Passive House certification schemes
      • Selection of building envelope components
      • Selection of heating and ventilations systems
      • Trade-offs: floor plans and volume-surface factor
      • Compensation for heat losses from poor compactness
      • Design auditing: PH certification


    • Design co-operation
      • Requirements for spatial planning, space allocation for HVAC equipment, and routing for HVAC installations
      • Avoidance of unnecessary thermal bridging
      • Performance of heating system with regard the thermal properties of the building envelope
      • Designers’ solutions for whole building performance


    • Construction
      • Performance based bidding, i.e., decision making based on performance, quality, delivery etc.
      • Selection of contractors: commitment, experience, references


    • Commissioning
      • Equipment testing
      • Air tightness tests
      • Balancing of the ventilation system
      • Energy consumption after one year of use


    • Maintenance
      • User instructions
      • maintenance manual