Every year since 1998, builders and designers have diligently completed the BRANZ Materials and Characteristics Survey. Here we report on the findings from the 2017 survey.
RESPONSES TO the annual BRANZ Materials and Characteristics Survey provide valuable information on house sizes and the materials used in the construction of new houses and non-residential buildings across New Zealand.
The size of new dwellings decreased slightly in 2017, easing to an average floor area of 207 m² (Figure 1). Floor areas increased strongly in the early 2000s, before plateauing and easing back down this decade. This trend may reflect constraints in land availability and housing affordability in general.
Weatherboards of various materials have overtaken clay and concrete bricks as the most popular wall cladding material for new houses (Figure 2). A preference towards lightweight claddings in the Canterbury rebuild, a historically very strong market for brick cladding, appears to have tipped the balance away from bricks from 2013 onwards.
While the traditional timber weatherboard has enjoyed a resurgence, fibre-cement and uPVC are also common materials for weatherboard profiles.
Autoclaved aerated concrete (AAC) has seen notable growth, selected as a substitute for polystyrene rigid sheets in plastered finishes.
Sheet steel remains the dominant roof cladding material for new houses (Figure 3). Tiles (metal and concrete) are the second most popular roof cladding, although their market share has declined over the past 3 years. ‘Other’, which includes claddings like membrane roofing and various shingle options, has slightly gained share.
The value of new non-residential buildings consented has continued to increase, reaching almost $5 billion in 2017. Within this, commercial (hotels, motels, retail and offices) and industrial (factories, storage and farm) buildings have increased since 2016.
Across non-residential buildings, sheet steel is the most common wall cladding, with 60% market share. This is underscored by its dominance on industrial and farm buildings.
In distant second place is concrete with 19% share of wall claddings, which includes tilt slab, in situ and concrete block. Insulated metal panels follow this with around 15% market share.
Sheet steel is the dominant roof cladding for non-residential buildings, with a market share of over 70%. This is followed by ‘other’ on 26%, which is mostly specialist membrane materials.
Download BRANZ SR396 from www.branz.co.nz/study_reports.
Articles are correct at the time of publication but may have since become outdated.