Te Papapa School Extension, Onehunga

A classroom extension for Watts & Hughes in 2025, built to the Ministry of Education's standard classroom design, the same template rolled out across Auckland schools.

We were the insulation subcontractor. Supply and install, to the specification the designer had already set. That is worth being clear about, because on a job this size the value is not in redesigning anything. It is being sharp on price, getting the right product to site, installing it properly, and not being the trade that holds up the programme.

The specification called for three systems inside one envelope, which is common in school work.

Autex GreenStuf through the walls and ceiling. A polyester product that covers the thermal and the acoustic requirement in one, which suits a classroom, where sound control matters as much as warmth.

James Hardie Mineral Wool where fire and acoustic ratings overlap. Those junctions are the ones worth getting right first time, because the next trade covers them almost immediately and nobody wants to open them back up.

Kingspan rigid board where the assembly depth will not take enough polyester or glasswool to reach the required R-value. Rigid PIR delivers more R per millimetre, so the H1 construction R-value is met without widening the framing.

Three products in one envelope means three install methods, three sets of fixings and three deliveries to coordinate. Handled badly it becomes a sequencing problem for the main contractor. Handled properly it is invisible.

Schools also run on fixed dates. The building has to be complete and signed off for the start of a term, so there is no room for an insulation scope that runs late.

Contract value $23,000. Installed to specification, sequenced to the Watts & Hughes programme, signed off without rework.

If you are pricing a Ministry of Education classroom build or any Auckland school extension and need an insulation price, send us the drawings and we will come back within a business day.