Virginia, Co. Cavan Deep Retrofit Case Study

Breaking Down the Details

Floor Insulation

150mm KORE Floor EPS70 Silver, EPS perimeter strips and an 80mm screed with underfloor heating was installed over the original uninsulated concrete floor, achieving a U-value of 0.15W/m²K.

Wall Insulation

The original 500mm stone walls were upgraded with 12.5mm plasterboard fixed with plaster dabs internally. 150mm of KORE External EPS70 Silver insulation and Kilsaren Ceresit External Wall Insulation render finish which achieved a U-value of 0.19W/m²K. The walls were also extended upwards and the window openings raised off the ground.

The KORE Warmroof Solution

To keep the attic space heated, KORE utilised an innovative warmroof solution with expanded polystyrene insulation to meet SEAI’s requirements for insulating an attic space. This warmroof system increased the home’s energy efficiency, decreased air leakage, reduced the risk of condensation, minimised the risk of thermal bridging and allowed for a heated indoor environment for both storage and services.

Internally, 165mm of KORE EPS70 Silver was fitted between 175mm rafters at 400mm c/c, and 12.5mm plasterboard was fitted to the sloped and flat ceiling.

Externally, the roof was fitted with 18mm OSB board and taped at all joints. 50mm of KORE EPS100 White was placed on top of the OSB board, followed by sarking felt and timber battens and counter battens to increase airflow. Solar PV panels (16.64m² PV array) were then placed in-line with the slate roof, generating 2,297 kWh/yr of electricity. This innovative EPS solution minimises the risk of perforations in the airtightness layer, and ensures continuity of the airtightness layer with the warm roof.

Heating System & Ventilation 

KORE installed a 6kW Daikin ERLQ006CAV3 air-to-water heat pump to provide indoor space heating and underfloor heating. A Lunos V30/60 whole-house demand controlled ventilation system was also installed, along with occupancy and humidity sensors.

Windows & Lighting

KORE chose Camden uPVC triple-glazed windows with a U-value of 0.90W/m²K and 100 percent LED lighting throughout the entirety of the house. The windows were set out into the insulation layer which minimised thermal bridging. An electric car charging port was also added to the front of the house, diverting excess electricity generated by the solar PV panels when available. This can help further reduce the occupant’s carbon footprint.

The “KORE” House

With a total budget of €140,000 – or broken down to €80,000 towards the rebuild and €60,000 towards the energy efficiency works, KORE was able to renovate a derelict house from top to bottom. We achieved a final BER rating of A2 (29.65 kWh/m²/yr) and reduced carbon emissions to 6.88kgCO₂/m²/yr. The final air tightness test results came in at a respectable 2.21m³/hr/m² @50 Pa. SEAI provided partial funding at 50% for the energy efficiency works, reducing the cost to €110,000.

The “KORE” house represents a total expanded polystyrene (EPS) solution, showcasing all KORE has to offer under one roof. KORE EPS was utlised as floor insulation, external wall insulation and as a warm roof solution, creating a low energy build with significantly reduced energy demand and carbon emissions – all while paying close attention to the airtightness layer around the roof and external walls, and minimising thermal bridging at the junctions.