A sum of money set aside in the construction contract for items which have not been selected and specified in the construction contract. Best kept to a minimum number and used for items who's choice will not impact earlier stages of the construction. For example, selection of tile as flooring may require an alternative framing or underlayment material.
Alloy steel blades hack saw blade
Alloy steel hack saw blades are heat-treated and hardened. As a result, they retain their edge sharpness longer than standard alloy blades. Additionally, while the tooth edge is hardened steel, the back of the blade remains flexible to combat twisting fatigue.
Alpine
Plants from high mountain regions. Anything that is from above the tree line. They are able to overwinter beneath deep snow protected from extreme low temperature by their moisture.
Alpine house
A special greenhouse created to meet the requirements of alpines. It is usually kept cool in the summer by shading the glass. In the winter it is unheated unless it needs to provide protection from very severe cold.
Alteration
A change in, or addition to, an existing building.
Alternate
Leaf form, where the leaves are arranged singly at different heights on the stem. Compare opposite and whorled.
Alternating current (ac)
Electrical supply in which polarity of wire. Reverses rapidly (e.g. 60 cps).
Alternative fuels
A popular term for "non-conventional" transportation fuels derived from natural gas (propane, compressed natural gas, methanol, etc.) or biomass materials (ethanol, methanol).
Alternator
A generator producing alternating current by the rotation of its rotor, and which is powered by a primary mover.
Aluminized steel
Sheet steel with a thin aluminum coating on the surface to enhance the steel's ability to withstand weathering.
