Live blog of speech by Padraic Davis of MCO Projects

Padraic Davis is speaking about retrofitting of historic buildings in Ireland and Germany:

 11.30am: Study that compared Irish and Norweigan buildings between the mid eighties and mid nineties found an avg indoor temperature of 15C in Ireland and 21C in Norway

 11.31am: Applying any substances to the walls of historic buildings that block moisture can cause mould, moisture and cracking. Materials used when upgrading historic buildings need to be hygroscopic

11.34am: Padraic is talking about fairly significant grants that were available for energy retrofitting & renewables in Berlin - in 1993

11.38am: Davis is talking about Booterstown convent now, profiled recently in Construct Ireland.  He's pointing out that conservation concerns meant no insulation could be applied to the walls of the historic building during the retrofit

11.43am:  Sand-lime (calcium silicate) board is an ideal material for insulating historic buildings - has good hygroscopic properties 

11.48am:  Studies in Germany have indicated that sand-lime boards (lime mixed with sand and then baked) performed well in terms of water management and thermal performance. Heat loss through the walls was reduced by more than 50 per cent

11.50am: Properties of lime cause water to be drawn out of the wall 

11.51am: Internal insulation requires the use of a vapour-permeable material

11.53am: The government should set up a state bank to fund building energy renovations

Q&A

11.54am: Audience member asks Padraic of potential for mechanical ventilation in historic buildings, and whether this would allow for more insulation to be installed as it would remove moisture from the air and help to prevent condensation. Davis says he has issues with mechanical ventilation in residential buildings because there is no culture of building maintenance in Ireland and these systems need to be checked every few months, he says. He has installed mechanical ventilation in historic buildings but isn't sure he'd recommend it all the time. 

11.58am: Davis recommends using lime-sand boards for upgrading historic buildings as it can halve the U-value of the walls, though he stresses such products are new to Ireland

That's all from Padraic Davis, next speech to be live-blogged here :