4 Irish PH/EnerPHit Projects - Lessons learned

Speaker: Seamus O'Loughlin from Viking House

Menezes

This 2006/2007 project is an 80m2 renovation + 70m2 Passive Extension with U-values of 0.10W/m.K for the walls/floor and roof.

Lessons learned; fungus mould on the trap-door when we returned after Christmas, clients continued to dry clothes in the house, the before and after air tightness result was 15 and 1.3.  Mother in law used to visit and keep her coat on and go home after 20mins to warm up, now she takes off her coat and sits on the floor playing with the kids. The PHPP came in at 23kWh/m2.annum, we would have failed on air-tightness and for not using windows with a low enough U-value, but it showed we were getting close.

Glencullen

Passive House Renovation in 2008 of a 220m2 Bungalow with 15m2 Solar Heating. The initial PHPP calculation showed a space heating demand reduction from 220 to 15 kWh/m2.

Lessons learned; Climate data for Dublin not accurate when you head into the mountains. High water table could be causing higher than calculated heat-loss. The client used a non Passive front door which swelled in winter from condensation on the inside. Winter solar gain was restricted because the trees to the south were never topped. The return temperature from the Paul HRV unit was 14 degrees on the 4th of Jan this year when it was minus 10 outside which caused draughts. When the stove wasn’t lighting the TV room is the coldest room in the house, the unlit stove is like a cold radiator, and yes it has valves! The air tightness result was 1.2, maybe we should have persevered!  We should have installed Solar Dump pipes around the foundations and beneath the house. 2 teenage daughters can exhaust 5 days heating from the 2,000L winter heating solar tank in a few hours because “its free right”. The heating demand was reduced by 93%, the oil heating system was retained but Theresa now uses 300L of oil/annum instead of 4,000L so the house is within the PH standard as regards usage.

Rathdrum

Passive House Renovation and Extension in 2009, this one ticks all the EnerPHit boxes, it has an air tightness result of 0.9ac@50kPa and is presently going through certification with Mosart. Its Irelands first A1 rated renovation and because of the windmill and PV panels its an energy plus house. It uses PH certified windows and my PH approved foundation system for the extension.

Lessons learned; The air tightness was tedious and took a long time, if we were back again we would do this differently by tackling it from the outside. There’s excess summer solar thermal heat and we should have installed a method of dumping this beneath the house. We would have used a cheaper equally effective roofing method, like our externally insulated/externally air-tightened roof method. I’ve asked the client what his heating bill is, he always says he doesn’t know!

Olive

Passive House Renovation 150m2 and 75m2 Extension in 2009, Externally Insulated Timber Frame Extension. The airtightness result is 0.97ac@50kPa, the PHPP came in at 24kW/m2.annum mainly because the orientation was off, we installed solar heat dump pipes beneath the house but solar was never installed due to budget. We used 3 FiWi HRV units which showed return air temperatures of 17 degrees on the 4th of Jan this year when it was minus 11 outside. By using FiWi HRV we had to enter a 12% reduction in HRV performance into the PHPP which increased the heating demand from 21 kW/m2.annum to 24kW/m2.annum because its not on the approved list.

Lessons learned; We used Munster Joinery Passive House certified windows. Their door wasn’t certified at the time and has an aluminium threshold which was the coldest spot in the house (12 degrees) on the 4th Jan this year. The Plumber went bananas on the heating budget and ran un-necessary heating zones everywhere. I had the client convinced not to put any radiators upstairs but the plumber and architect talked her round, she hasn’t used them in the last 2 very cold winters and now wants’ them removed, we have a new plumber now! Olive says she used to live in the coldest house in Dublin and that she now lives in the warmest house in Dublin!  We have all the documents with Mosart to certify this one also but it depends on our budget!