The project consists of a Regional Library, Local Area Office for Limerick County Council together with a new Courthouse for the Department of Justice, all arranged around a new linear public space for the town of Kilmallock. The project forms a new Civic Precinct strategically aligned so as to extend the building line of the Main Street. Although each building use has very differing requirements, a coherent environmental strategy has been used throughout each of the elements the project.
Deep-plans, Day-lighting and Ventilation
Although an overall building depth of up to 24 meters has been achieved, all spaces are day-lit, making use of diverse techniques to introduce natural lighting. Ceiling heights are generous, increasing daylight penetration throughout. In lower office areas, ceilings have been cut back to allow windows slide above to parapet-level so as to further increase the depth that sun can enter the building.
Bands of clerestory glazing bring light deep into the plan. South-facing glazing is first modified by the use of a graded, ceramic frit which stops radiant heat on the outside face of the double-glazed unit, thus reducing overheating. Light is then tempered internally by the use of pivoting fabric screens which provide controllable shade to occupants. Extensive northern glazing is provided, giving even daylight while avoiding the problems of insolation.
Wall and ceilings are further used to reflect light within the building, the white plaster fins bounce light into the offices. Deep reveals to the courtroom walls reflect light into the space, while the suspended roof of the reading room reflects daylight deep into the interior.
Artificial lighting is photo-controlled, responding to internal lighting levels by automatically dimming. It is activated by occupant movement which further increases energy efficiency. Opposing bands of high-level windows, operated by motorised actuators, provide natural ventilation across internal spaces, while manually operated low-level windows provide local controllable ventilation for occupants.
While energy consumption is minimised by achieving high levels of insulation, excellent air-tightness (1.6m³ h ¹ m ² at 50 Pascals), eliminating mechanical ventilation where possible and maximising day-lighting, an equally considered approach to both energy generation and embodied energy has also been pursued. The building is constructed using GGBS concrete– a waste-product of the steel industry, reducing the carbon footprint of the project. High levels of external insulation, combined
with strategic use of glass, reduce heat loss and maximise passive solar gains. Use of indigenous materials including local stone reduce energy of material transportation. A biomass wood-pellet boiler located in a centralized plant room generates heat for each of the three buildings with each building metered separately. (This represents an economy of space compared to an individual plant per building.) This is further supplemented by solar panels for hot water requirements. An array of photovoltaic panels, laid out on south-facing roofs, provide electricity for use in the building, excess being sold back to the grid.
Based on CIBSE benchmark energy consumption figures for court buildings, libraries and offices, it is estimated that a 45% reduction in carbon emissions will be achieved through the use of the biomass & PV. The anticipated Net Carbon Emissions for the project is 43 Tonnes/Yr.