ENERGY

Building Code Requirements

 

The intent of Clause H1 Energy Efficiency is to provide for the efficient use of energy and to set physical conditions for energy performance.

 

H1 covers the energy used in buildings for:

 

● Modifying temperature

 

● Modifying humidity

 

● Providing ventilation

 

● Providing hot water

 

● Providing artificial lighting (for non-residential buildings only)

 

The performance criteria of Clause H1 is limited to the provision of adequate thermal resistance and limiting uncontrollable airflow. Other influences of thermal performance such as thermal mass, orientation, airtightness and solar and internal heat gains, should also be taken into account.

 

Clause H1 states that water heating and HVAC systems should limit the energy used to perform their functions.

 

Energy efficient lighting is not covered for housing under the requirements of H1, and nearly all hot water systems available in the New Zealand market are compliant. In addition, there are no specific performance criteria for humidity and ventilation, the only real impact of H1 on the design and construction of houses is the specification of thermal insulation.

 

The Building Code requires enclosed spaces where temperature or humidity are modified to provide adequate thermal resistance and to limit uncontrollable airflow in certain buildings. It also sets out physical conditions likely to affect energy performance, and requirements for hot water systems, artificial lighting and HVAC systems.

 

Healthy Homes Energy Rating System

 

Ideally, NZ needs a simple energy rating that is easy and cost-efficient. The UK and Europe have for over 15 years had Energy Performance Certificates (EPC's). These are not perfect but are quick, cheap ($200-300) and mandatory. As a result, 22 million properties have been rated in the UK and Europe.

 

Energy Step Code Aotearoa with Primary Energy (ESCAPE)

 

The Energy Step Change Aotearoa with Primary Energy (ESCAPE) is a network of New Zealand’s built environment professionals who are working together to create a building standard to put New Zealand on the path to a zero-carbon future. ESCAPE is made up of developers, engineers, architects, NZ Government, contractors and material suppliers.

For further information; https://energystepcode.nz

 

ESCAPE looks to resolve and define the following:

 

Issue one:

The way we measure energy in buildings is unlike anywhere in the world. A universal measurement needs to be adopted.

 

Proposed Solution:

TUI – a measurement of total usage intensity 1 kWh / sqm*yr = 1 TUI.

Issue two:

(a): The Building Code currently doesn’t require heating or ventilation which are key to warm, healthy homes (b): There is no performance based requirement to control the internal environment in buildings.

 

Proposed Solution:

TEDI – a measurement of thermal energy demand intensity.

 

Define a minimum performance requirement for indoor air quality: 18-25 Degrees C | 40-60% Relative Humidity | <1000ppm CO2

Issue three:

The existing legislation doesn’t supply any future projections so the industry can’t identify what needs to be planned or managed for the future.

 

Proposed Solution:

Key dates and starting points outlined as a projection for the industry to identify what action is planned, and when it should be achieved by:

Currently, we recommend following the Healthy Home Design guidelines and when the ESCAPE standard is available, it will likely be adopted by the Superhome Movement as a step change pathway to assist in creation of buildings with zero operational carbon.

 

Alternatively, use ISO 52016-1:2017 Energy performance of buildings

 

Verification

 

All Healthy Homes will be monitored for energy usage to provide a feedback loop to confirm design assumptions. See Monitoring.

 

Recommended Healthy Home guidelines for Energy Reduction are set out in the table below: