Confident new council offices for North Tipp

Nenagh has become the latest town to acquire smart new civic offices with plenty of parking for the officials working there, writes Frank McDonald, Environment Editor

Local authorities have emerged from the shadows in recent years, commissioning new civic offices for themselves - and the public. In doing so, they have replaced often makeshift and scattered accommodation and made confident statements for the 21st century.

The latest to do so is North Tipperary County Council, in partnership with Nenagh Town Council, on a sprawling 14-acre site at the western edge of the county town. It fell to ABK Architects to give physical form to the brief and create a sense of place in an area being rapidly colonised by suburban housing.

ABK are no strangers to the design of public buildings. From Paul Koralek's Berkeley Library in Trinity College, one of Ireland's great modern masterpieces (dating from 1967), to Offaly County Council's award-winning Áras an Chontae in Tullamore (2003), they have shown that this is their true mètier.

In Nenagh, one of the architects' main tasks was to give the new building a civic presence on the old road to Limerick. Robert Davys, the partner in charge, managed to persuade the county council that it should acquire and demolish an adjoining bungalow to provide an adequate frontage for the building.

Located beside the town's fire station, the new civic offices are marked by a stainless steel and bronze totem pole (by sculptor Colm Brennan). Rising up behind it is the county council's chamber, with its circular shape and zinc-clad roof tilted at an angle of 15 degrees, providing - in effect - another totem.

The town council's chamber, by contrast, is triangular - to emphasise its separate identity - and between these two elements is the main entrance. It opens into an impressive double-height concourse which runs the full length of the building, with the partially-screened staff canteen right at the end..

Everything is arranged around the charcoal grey dolomite-floored concourse - public counters for housing and planning, two wings of open-plan offices extending to the west and another wing to the east, with its own atrium, containing offices and consultation rooms for the Health Services Executive (HSE).

The design allows for further expansion to provide a third wing to the west, if this is required. Robert Davys regrets its absence, on the basis that "visually, three is always better than two". But since the building already has 6,500sq m (69,965sq ft) of office space, a third wing was not seen as necessary at this stage.

Fairface concrete columns are oval shaped, formed from plastic moulds, with those on the perimeter set at right angles to the main space to give slender sight lines. At rainwater pipe locations, columns are cut back to accommodate pipes and the shape of the oval is completed with aluminium.

Doors, architraves and handrails are all done in maple. The county council's chamber has laminated Douglas fir trusses and walls partly panelled in birch. A tall lancet window faces towards the town where until recently the council was operating from six different buildings, including the old courthouse.

The courthouse is being refurbished by the Courts Service, while the old Town Hall has been handed over to Nenagh Community Services. The town council's chamber is more modest and, unlike the fixed granite-topped tables of the county council's chamber, its furniture is moveable to allow other uses.

Offices for the county manager and senior council staff are located right beside the entrance to the county council's chamber; these were originally to be party offices, which have been accommodated elsewhere. Altogether, including fit-out, the building cost €22 million, mostly self-funded.

A south-facing community crèche, costing an additional E890,000, has been provided at the rear, behind extensive berms formed from the site spoil.

These berms are quite irregular and covered in thistle, dock and other weeds. Between them and the civic offices, a large area is set aside for a meadow.

As in Tullamore's Aras an Chontae, Nenagh's civic offices incorporate the latest "sustainable design" strategies, including natural ventilation and geo-thermal heat exchangers which supplement heating and cooling cycles through pipes cast into the building's coffered concrete ceiling slabs.

"Often, 'natural ventilation' means openable windows and nothing else, with the result that buildings overheat and people who sit near the windows are constantly in a draught while their colleagues further from the windows desire more air," Davys says. But the Nenagh Civic Offices are more sophisticated.

Exposed concrete is integral to creating a thermal mass to moderate the internal environment. South-facing offices are protected from solar glare by suspended mesh sun-screens, complemented by Himalayan birch or honey locust trees in the external courts which will ultimately provide more shade.

Natural ventilation in the largely open-plan wings, each 12 metres deep, includes large window vents, small high-level vents and baffled ventilators for "trickle" ventilation to avoid draughts. The high-level vents ensure that hot air can escape while incoming air distributes across the ceiling slabs.

The real test of the ventilation system came this summer when outside temperatures reached 25 degrees. Even though the pipework in the slabs was still being tweaked, none of the 250 staff working in the building complained, according to Karl Cashen, the council's environment director.

The design principles had to be adapted for the HSE wing due to its requirement for cellular offices, so an air-handling unit was introduced.

(The HSE, incidentally, might reconsider the appropriateness of placing a clunky suburban-style three-piece suite in its public waiting area; it strikes a very jarring note).

A computer-controlled building management system monitors all energy use.

"At an early stage, the use of a wind turbine was examined, if only as a symbol of energy saving. However, as the site is due to be surrounded by housing our client was concerned by the possible noise issue," Davys says.

Insulation used in the roof and external walls, some of which are clad in terracotta rain-screen tiles, is CFC-free and, with a thickness of 100 mm, considerably exceeds the requirements of the building regulations. Solar panels on the roof of each wing are used to heat water for wash-hand basins.

Rainwater from the roofs goes into holding tanks so as not to strain the local surface water drainage system; it is used as "grey water" for toilet cisterns. The extensive car-parking areas drain into the ground through "grassgrid" concrete, to be collected by French drains and then taken into the system.

However, with some 280 parking spaces and staff travelling by car from Roscrea, Thurles, Limerick and other areas, it is arguable that the consideration of making the building as "sustainable" as possible has been offset by all this car use; only one bicycle was parked outside the building last Thursday.