Deep retrofit & heat pump transforms Inchicore home

This article was originally published in issue 40 of Passive House Plus magazine. Want immediate access to all back issues and exclusive extra content? Click here to subscribe for as little as €10, or click here to receive the next issue free of charge

The upgrade features a wrap of 100 mm external insulation, boosting the U-values of the external walls to 0.27. The attic was upgraded with 300 mm of fibreglass insulation to deliver a U-value of 0.13, while the sloped ceiling was fitted with 100 mm of Isover Metac recycled glass wool, plus a layer of insulation board, giving a U-value of 0.17.

The house was also fitted with a new Viessmann Vitocal 200-A air-to-water heat pump, which provides low temperature space heating via an underfloor system downstairs and low temperature radiators upstairs. The Monobloc Vitocal 200-A is available in outputs of 2.3 to 11.8 kW, with all models in energy classes A++ and A++++. The heat pump was supplied by Dublin-based Viessmann distributor Precision Heating.

The house also features new double glazed low E plus windows and new composite doors with a U-value of 0.9, as well as an Ermen heat recovery ventilation system.

“These measures reduce energy usage from over 400 to 50 kW/m2/yr with a 90 per cent reduction in carbon dioxide emissions,” John McMahon of Energlaze (www.energlaze.ie) told Passive House Plus. “It also delivers vastly reduced energy bills typically as low as €350 to €400 per year, whereas the previous G rating could cost up to €4,000 per annum.”