EnerPhit Certification was issued by the Passive House Institute in Germany for our latest low energy house retrofit in Dublin 4 last week. This represents the culmination of 16 months of work from initial design to completion in close collaboration with Integrated Energy to achieve the optimal thermal performance and air tightness. The preliminary air test achieved 0.7 air changes per hour – 30% below the maximum EnerPHit standard with final air test achieving 0.63 which is within new build passive house standards.
Design Challenges : Contextual planning constraints, orientation and house size were all challenges faced and overcome. Existing walls had to be upgraded to meet the stringent insulation standards but most critically air tightness performance. This necessitated careful detailing, close site supervision and a very high level of workmanship and contractor expertise from Cyril Mannion in Passive House Builders. Window selection was also a careful consideration but given the EnerPHit standards to be achieved the decision was taken to use a high quality triple glazed system (class 4 air tightness) but without the extra cost of thermally broken frames and a passive certified system thus controlling cost verus energy saving return without compromising EnerPHit certification. The ventilation strategy was also carefully considered in tandem with high acoustic standards sought necessitating the use of two Dantherm HCH5 air handling units with summer by-pass facility.
Key Statistics : Annual specific space heating demand – 21kWh/sq.ma; Annual specific primary energy demand (heating, ventilation, appliances) – 109kWh/sq.ma; Airtightness of building envelope – 0.6h-1
Passive House Plus: This is only the second domestic EnerPHit project in Ireland to receive full certification and is the largest. Full techical details will be outlined in the forthcoming November issue of Passive House Plus online and in print. Further project images and details will be posted to our projects section of the website to coincide with this publication.
End Result: We are very pleased with the end result not only in terms of technical performance but also quality of finish and completion within a challenging programme. We now look forward to our next low energy challenge – retrofit or new build!