Slab Edge Insulation (SEI)

The slab edge of a foundation can be responsible for approximately 80% of the slab’s total heat loss, with further research showing that thermal resistance does not significantly improve by fully extending the insulation under the slab or by increasing the thickness of the insulation under the slab. The reason being that, with no insulation on the perimeter foundations, most of the heat is conducted along the slab and out through the exterior face of the footing. This suggests that insulating slab edges is far more effective for preventing heat loss than insulating the underside of the slab.

Extruded Polystyrene (XPS) is considered the best material for insulating the slab edge. XPS is resistant to moisture and has a higher compressive strength, making it a good option for foundations that may be subjected to high loads or in areas with high moisture levels.

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    Wall Insulation
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Designed to be installed onto an existing concrete foundation, Accumen Shapes can manufacture a wide range of SEI retrofit solutions to meet the requirements of your project, so contact us now to discuss your requirements!

Ask for Accumen SEI Boards, the ultimate SEI solution!


Accumen Shapes are the New Zealand distributors for Foamex XPS. Foamex XPS is produced without the use of toxic, ozone depleting substances, making it the best environmentally friendly solution for any project.

Accumen Shapes uses Foamex XPS to manufacture robust pre-plastered SEI boards for the ultimate SEI solution. Accumen Shapes uses patented manufacturing technology to apply the KickIt® plaster to Foamex XPS boards.

Accumen Shapes have been manufacturing and supplying the New Zealand building industry with our robust KickIt® pre-plastered shapes and mouldings for over 30 years!

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Accumen Shapes Ltd is a New Zealand owned and operated business that specialise in the manufacture of traditional and contemporary lightweight exterior decorative mouldings that can transform your existing or planned building into a unique architectural dream without major structural re-design. 

Accumen Shapes also manufacture a wide range of Insulation Products for the Commercial and Industrial business sectors.

Accumen Shapes custom manufacture a wide range of lightweight exterior mouldings including columns, architraves, cornices, window cills (sills), fence caps, quoins, false vents and shutters, arches, bands/dado lines, parapet mouldings and chimney surrounds. In addition we also manufacture bBOLD signage, shapes, film sets and theatre props.

Accumen Shapes operate New Zealand’s only locally based manufacturing facility for Pre-formed Fibreglass Pipe Sections. We have manufacturing capabilities for FoamGlas (Cellular Glass Insulation), Ravatherm and Foamular XPS shapes and sheets, PUR, PIR and Phenolic shapes and sheets, Rockwool pipe section and Siliner and Ductliner boards. We also have New Zealand’s only fully automated laminating operation for laminating foils, cloth, ridged insulation foams etc to insulation blanket, boards etc


In 1991, a small company was formed based in Otahuhu, Auckland, New Zealand. Since establishment, we have evolved into the present company known as Accumen Shapes Ltd, which develops and specialises in the production and manufacture of KickIt® high-quality lightweight decorative shapes and mouldings, and a wide range of commercial and industrial insulation products.