Considering there is just 5 certified passive houses in Ireland, I'm not sure you will get many responses. I'm not sure most Architects understand Passive house standard. The BER and A rated buildings along with Part L compliance causes enough confusion without encouraging clients towards Passive. I noticed last week while visiting a few passive houses nearing completion that this standard of build is excellent at maintaining stable temperatures even without the HRV. Buildings that are airtight with no thermal bridging and constructed using materials with good thermal inertia properties. Have a reduced Heat Load. It is quite easy to achieve passive standard in apartments, but to do it cost effectively it requires design to maximise solar gains and reduce superfluous external envelope. Passive houses are well suited to urban sites as they are excellent acoustic sealed boxes. The HRV provides 30 air changes of filtered air. Passive house can be done for within 5% of conventional build costs, but this is dependant on having a good design professional. Its quite sinister how the Institute has set its stand against low energy standards when this is just what is needed, a requirement that every building should have a skilled design professional with technical skills to oversee refurb and new build. All those unemployed Architects and technicians could use the next 3 years of down time to gain the skills the industry will require. But neither the schools of Architecture or the Institute has a clue. I suppose how can an industry which built apartments with drylined precast slabs change to a more sustainable standard overnight. Anyway here's a useful introduction.