Sustainability Series – Block N1 Central Park

Sustainability Series – Block N1 Central Park

Design, Sustainability, Work

Block N1 Central Park – A new, 100% carbon-free building  targeting LEED Gold

This site is located within the Central Park business campus in Leopardstown. The proposed development consists of three separate office buildings: N1, N2 and N3, and a wellness centre, which sit over a shared lower ground and basement car park.

The N1 project is at construction stage and it forms the last remaining site in Central Park. Block N1 is a Grade A Speculative Office Building of over 18,000m2, and it perfectly bookends and outlines the approach taken by Henderson Park in terms of sustainable building design.

Central Park is well established with numerous high profile tenants occupying space in this thriving business district. The site is well serviced from the Green Luas line, and bus termini. The Park has substantial car parking available also.

The building consists of nine levels of lettable tenant office space and two basement levels which include parking and amenity spaces. The works include the installation of new M&E Shell and Core installation, including Reception, Atrium, Shower suite, ancillary space, and the full CAT A fit-out of the nine levels, with Four Pipe Fan Coil Units and LED lighting.

The building is designed to cater for multi-let floor plates and is also suitable for a single occupier.

The building is served by best-in-class MRL elevators, with 2 no. running through the Atrium, known as the “Scenic” Lifts.

Energy Rating and Carbon Free

The target BER is A3, fully NZEB compliant, with all the building’s heating provided by renewable means, and from an active energy basis is 100% carbon-free.

Sustainability was at the forefront of the building design, and the targets in terms of Carbon Performance Coefficient (CPC), Energy Performance Coefficient (EPC), and Renewable Energy Ratio (RER) all outperform the reference building by approximately 15%:

CPC: 0.84

EPC: 0.82

RER: 0.14

Sustainable design features


LED lighting will be installed throughout the building. PIR occupancy sensors were incorporated in open plan areas to minimise energy use.  A lighting control system was installed to monitor and facilitate ease of control of the systems.

Energy consumption monitoring

Energy metering will be installed on each floor distribution board, as part of the overall LEED strategy. This allows for monitoring of the overall usage through the central BMS system. Furthermore, all heating / cooling is sub-metered and linked to the BMS. Power factor correction was installed within the main switch room to further limit energy wastage.

Water consumption management and monitoring

Water meters have been added to each tenant floor plate. These are linked back to the central BMS.  They notify if high levels of water are being used, which may be caused by leaks in the system. Individual cleaners’ sinks are provided with separate meters, in line with LEED credits. Booster pumps have incorporated variable speed drives. All sanitaryware including WHBs, showers and toilets are low flow/flush, with taps being sensor-operated.

Heating and cooling

The high-efficiency 4-pipe heat pumps provide heating and cooling to tenant and landlord spaces.  All tenant spaces are provided with energy metering linked to central BMS. The office and toilet AHUs have heat recovery incorporated within each unit to ensure maximum efficiency. A heat recovery unit is dedicated to the basement amenity space. All ductwork associated with heat recovery plant is thermally insulated.  All domestic hot water is produced by Air Source Heat Pumps.

The energy contribution from the heat pumps is renewable energy, this equates to 10.79 kWh/m²/year of primary energy being provided on site, approximately 14% of total primary energy come from renewable onsite.

Summary of sustainable features

  • High-performance construction envelope including low u-value and g-value
  • Air tightness construction
  • Multi-purpose unit (4-pipe heat pump technology) for heating and cooling
  • Air source heat pump for hot water system
  • Heat Recovery mechanical ventilation
  • Low specific fan power installed unit
  • Low installed lighting power & intelligent lighting control
  • VSD’s on pumps / fans

The sustainable design of the proposed development presents an opportunity to ensure the overall building performs efficiently and meets the NZEB challenges. The entire building was dynamically modelled with the sustainable inputs, and the analysis and the calculation of the building performance metrics to show compliance with the Part L and BER.


The building sustainable objectives have been measured through the LEED assessment process during the design and construction. The development will achieve the LEED Gold rating.