At the SEAI “See the Light” Conference in UCD, Dublin earlier this month, Martin Vaughan of the DOECLG outlined the targets for 2013-2016 part L energy performance of new dwellings. It is anticipated that new housing will be required to achieve an A2 energy rating/BER energy value of 45kwh/m2/yr.

Having completed the 87 South Avenue project in 2011 which achieved these values with conventional construction (ie: not passivhaus standard), what is required to reach this standard? The outline specification of the dwelling was as follows:

Walls:  cavity wall construction with 175mm platinum bead insulation (u value 0.17w/m2k)

Roofs: timber construction insulated to u value of 0.16w/m2k

Exposed floors: solid concrete insulated to u value of 0.15w/m2k

Airtightness: A value of 3 m3/h.m2 was achieved with wet plaster finish to inside face of walls and proprietary membranes to roof construction.

Heating & DHW: Nibe Fighter geothermal heat pump 430% efficiency (HARP)

MHRV: Installed and operating at assumed efficiency of 90%/specific fan power of 0.5w/l/s

Solar water heating: 4.8m2 aperture area of evacuated tubes

The building had a floor area of 285m2 and was compact in terms of volume to external envelope but had very limited access to south facing solar gains. The mechanical installation was a significant element of the budget – clearly there will be substantial additional capital costs associated with 2013 part L compliance!

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