NATA
National Association of Testing Authorities. The national body that test laboratories are registered with. To have NATA registration requires a test laboratory to meet and maintain stringent test standards.
NURB surface
Non-uniform rational B-spline. A mathematical model commonly used in computer graphics for representing and generating curves and surfaces.
Natural Finish
A transparent finish, which does not seriously alter the original colour or grain of the natural wood. Natural finishes are usually provided by sealers, oils, varnishes, water repellent preservatives, and other similar materials.
Natural Ground Level
The natural level of a site.
Neoclassicism
An 18th-century reaction to the excesses of Baroque and Rococo, this European art movement tried to recreate the art of Greece and Rome by imitating the ancient classics both in style and subject matter.
Neoimpressionism
A school of painting associated with George Seurat and his followers in late 19th-century France that sought to make Impressionism more precise and formal. They employed a technique of juxtaposing dots of primary colours to achieve brighter secondary colours, with the mixture left to the eye to complete (pointillism).
Net Floor Area
See Area
Net Habitable Floor Area
See Area
Neutral Cure Silicone
Sealants that cure with non-acidic cross linkers, do not exhibit a vinegar odour, and are usually compatible with copper and masonry substrates.
Newel Post
The upright post of a staircase which supports the handrail – often turned and decorated.
Niche
A recess in a wall, usually to house a statue.
Noggin or Nogging
A timber wall-frame or small horizontal pieces of timber fixed between the wall studs.
Noise Reduction Coefficient
(NRC) a single number rating between 0 – 1.0 that describes the sound absorption properties of a material. The higher the coefficient, the more absorptive is the material.
Nomenclature
System of terms which is elaborated according to pre-established naming rules.
Non-Bearing Wall
A wall supporting no load other than its own weight.
Non-Potable Water
Water that is not suitable for human consumption.
Nosing
The front edge of a stair tread.
Nought
English language expression for the American zero.