House gets highest energy efficiency rating


A Golden Bay holiday home may be New Zealand’s most energy-efficient house, achieving nine out of ten stars under the Home Energy Rating Scheme — the highest rating awarded yet under the scheme.

The Golden Bay Hideaway’s “Little Greenie” house in Wainui Bay is so efficient that its room heating and hot water bills are expected to cost less than $50 per year. 

Its energy-efficient features include:

• large double-glazed windows orientated towards the sun,
• smart use of building materials — a concrete floor and adobe walls collect the sun’s warmth on sunny days and release it overnight,
• super insulated roof, walls and floor (more than double that required by the Building Code), and
• solar water heating.

The annual heating demand of the house is about 85% lower than for an average new build house, and about 97% lower than for an uninsulated house. It is the first home to receive a 9-star home energy rating under the government’s Home Energy Rating Scheme (HERS).

The voluntary scheme rates a home’s energy performance and recommends improvements. Homes are awarded a rating from 0 to 10 stars.