nzeb design ltd. usually works with a light earth infill consisting of pumice and/or wood chips and selected loams. This material combinations was very successfully used on many of our projects and produced appealing, stable walls with excellent thermal properties.The quarried race pumice has an aggregate size varying from 8 to 55mm.The wood chips are bark free, untreated, shredded waste wood and /or macrocarpa wood shavings and sawdust. Suitable loam can often be found on site or close proximity. A clay content of about 30% is ideal for the light earth method. The clay merely acts as an adhesive to hold the airpocket-forming aggregates together. The loam is soaked and agitated before mixing it at a ratio of approx. 20% loam to 80% pumice or wood chips in a mixer. The mix is then poured into a temporary shuttering system between the upright members of the frame (posts or studs). The mix is lightly tempered by hand and lateral support is provided by horizontal laths at regular intervals. When dry the walls will have a density of approx. 450-850 kg/cubicmetre, which together with the internal and external plasters will produce an r-value of approx. 1.2 sqm*K/W for the 200mm wall thickness. Temperature monitoring of our project in Mangawhai over the 2004 winter period has confirmed the good thermal properties. The inside room temperature of the unheated and uninhabited building never dropped below 14 degrees celsius.