If this is not possible, he actively discourages adding modern extensions to historic buildings because of the propensity of the older buildings to devour heat.
BERs range from a G for poor efficiency to an A1 for best efficiency" data-tiptheme="tipthemeflatdarklight"data-tipdelayclose="500"data-tipeventout="mouseout"data-tipmouseleave="false"data-tipcontent="html" class="jqeasytooltip jqeasytooltip72" id="jqeasytooltip72" title="BER" rating was achievable for the whole building, striving for passive house certification would have made no sense because of the physical marriage between a modern high-performance extension envelope and an old-style, solid Type of construction in which individual units such as blocks, bricks or stone are bound together with mortar" data-tiptheme="tipthemeflatdarklight"data-tipdelayclose="500"data-tipeventout="mouseout"data-tipmouseleave="false"data-tipcontent="html" class="jqeasytooltip jqeasytooltip115" id="jqeasytooltip115" title="masonry", minimally insulated structure with traditional sash windows and a four-storey construction that is just one room deep, resulting in all the main rooms having three or four external walls (meaning there is a high surface-to-volume area from which heat can escape).
Architect Bill Maxwell of Enniskillen-based Maxwell Pierce has worked on plenty of historic buildings with extensions, but making such dwellings work as single, seamless entities from an energy and comfort point of view can be difficult — unless you also have the opportunity to strip the older building back to its bare bones and start again from scratch, as was the case here.
But you’re also looking at a historic building that has been retrofitted to a building energy rating of A3, a spectacular achievement in anyone’s book.
After all, there are a whole range of challenges involved in trying to undertake a deep energy retrofit on a building like this — and some building conservation experts would argue that you shouldn’t even try to.
For a typical building, there is usually little difference in the two figures. Under Irish building regulations new homes must have an air-tightness of 10 m3/hr/m2.