No. 1 The Terrace, Wellington

NDY provided total building services design and supervision for the refurbishment of the building services at No. 1 The Terrace. The refurbishment comprised modernising the existing building services, concentrating in particular on the air conditioning and lighting systems.

A major driver for the refurbishment was the historical energy data, which confirmed that the building was extremely energy inefficient.

NDY proposed converting the existing air conditioning system from an on-floor air handling plant to large centralised air handling plant located within the basement, and a new services riser through the centre of the building core.

This was achieved by removing part of the level 1 basement floor to create a double height plant room for the central air handling units. The on-floor air handling units and other existing services were progressively removed and relocated within the on-floor plant rooms to accommodate the new supply and return air riser ductwork between the basement and roof plant room.

Further complications were created by the requirement to maintain the existing tenant in occupation during the refurbishment. Involving the tenant in the process and managing temporary relocations was critical to the overall project success.

The final HVAC solution vastly improved the energy efficiency of the building by resolving the on-floor air handling units, ineffective ductwork layouts, lack of any outside air economiser cycle, inefficient generation of heating energy and lack of effective energy management by the building management system.

Energy Reduction

Summary energy performance improvements are detailed below:

• Nett lettable area (NLA):  63.5% increase (11,297 to 18,462 m²)
• 1998 – 1999 Total Energy Consumption:   404kWh/m²
• 2006 – 2007 Total Energy Consumption:   245kWh/m²
• Energy reduction is 39.4%.