Glossary – our knowledge from A to Z

A frame structure that is delivered to the building site prefabricated and only has to be integrated into the façade. This enables large façades to be erected in a very short time.

A specific failure scenario in the loading of steel plates in tension in the direction of their thickness. A weakening of the material caused by thermal contraction strains during welding, which can be avoided by designing properly to suit welding techniques. Certain grades of steel are more resistant to lamellar tearing.

This type of glass consists of two or more glass plies bonded together with one or more interlayers, e.g. casting resin or a highly tear-resistant, viscoplastic, thermoplastic sheet.

This method of welding is primarily used for welding components that must be connected fast, need a narrow, slender weld seam and can accommodate only minimal thermal distortion. This type of welding is usually carried out without the need for a weld metal.

Latticino is a type of reticulated glass in which milky white glass threads are melted onto clear glass.

A clear, high-quality glass containing lead which is characterised, in particular, by its splendid shine.

This type of glass exhibits especially high light refraction, which is advantageous for the decoration and faceting. It is therefore very popular for drinking glasses, vases, dishes and chandeliers.

The addition of a covering of lead to a steel surface to protect against corrosion. The workpiece is immersed in a bath of molten tin or coated by an electrolytic process.

This special glazing method is based on the principle of framing small coloured, painted or etched (sandblasted) panes of glass with soldered lead bars (so-called cames) to form a complete pane which is subsequently mounted in a door or window.

Leadership in Energy and Environmental Design (LEED) was developed in 1998 by the US Green Building Council in order to create a system for classifying ecological construction. The system awards points for various environmentally friendly characteristics of a building. The higher the number of points awarded, the higher is the LEED certification.

A narrow, marginally projecting vertical feature (functional or decorative) on a wall or façade.

The height of a point on a structure above sea level or the reference level of the structure and expressed in a uniform system. Levels above the reference point are indicated by a plus sign, those below by a minus sign. On drawings, levels are indicated by a triangle symbol, solid for structural levels, outline only for finished levels.

The surveying, i.e. measuring, of the difference in height between two points.

A material used for levelling any unevenness in a floor. Self-levelling compounds spread out to form flat, level surfaces following a rough distribution.

The glazing to lift enclosures or cars consists mainly of safety glass. Despite the presence of this safety barrier, the usual regulations for glazing preventing falls do not apply here.

With this type of door the horizontally sliding leaf is lowered into its weathertight position upon being closed. The opening mechanism first lifts the sliding leaf out of its floor seals and then slides it to the side on rollers.

A precaution necessary for suspended components (e.g. sheet metal elements) that prevents them being lifted off by persons or the wind. This can be, for example, simply a screw positioned at a suitable point.

A ring with a stud on one part of the ring, the thread of which points away from the centre of the ring. It can be screwed into a female thread provided in a heavy component (e.g. façade element) for lifting purposes.

A ring with a nut formed in one part of the ring, the thread of which points towards the centre of the ring.

Such systems (re)direct daylight in a controlled way into interior areas deeper within the building, which means that the use of daylight and the interior illumination can be optimised. A light (re)directing system should help to reduce the amount of artificial lighting required.

This is the designation for a physical interaction in which the light transfers its energy to a material. Light absorption is a special case of the more general physical phenomenon of absorption.

This is a component that optimises the use of daylight by redirecting it further into the interior. Light shelves introduce a distinctive horizontal segmentation into a façade. They are particularly worthwhile in conjunction with double-leaf façades.

The light transmittance of a glazing unit is the percentage of solar radiation in the visible range of wavelengths (approx. 380–780 nm) that passes through the glazing.

The light transmittance of a single pane of glass for the visible range of the spectrum is approx. 82 %. Insulating glass has a light transmittance of < 80 % in this range.

A glazing unit with at least two panes of glass and a glass-fibre mat or glass fleece in the cavity.

This is an electronic semiconductor component. When a current flows through the diode in the forward direction, it emits light.

Concrete with a density not exceeding 2.0 kg/dm³. Lightweight concrete is a mix of cement, aggregates and water. The aggregates used include pumice, expanded clay, foamed slag, expanded shale, etc.

A form of construction in which one of the priorities is to save as much weight as possible. One main reason for lightweight construction is the saving of raw materials in the manufacture and usage of products.

This specifies the amount by which a certain dimension may deviate. For example, the thickness of float glass may deviate by 0.2–1.0 mm from its nominal thickness (depending on the thickness).

A lintel is a horizontal beam, usually made from timber, masonry, steel or reinforced concrete, over an opening in a wall such as a door or window. A lintel carries the loads from the section of wall directly above it and transfers these to the wall sections either side of the opening.

A test used to establish defects that are open to the surface of a material. All materials that are compatible with the test liquid and not too porous may be tested using this method. The test is used for checking weld seams, cast parts, etc.

Generally, this specifies the maximum load a building component can carry.

Location blocks prevent movement of the pane of glass within its frame. They are intended to direct forces acting on the glass to the loadbearing construction. In addition, they prevent contact between the edges of the glass and parts of the construction such as bolts, screws, etc.

A lock holds a door or window closed and prevents unauthorised entry. Locks are designated according to the position of the hinges: hinges on left side = DIN left; hinges on right side = DIN right.

This contract for goods with a preferred original condition is a declaration in which the supplier provides details about the original condition of the goods supplied and for which countries customs duties reductions apply according to the applicable free trade agreement.

A surface with the lotus effect has a water-repellent (hydrophobic) coating with a microstructure similar to that of the surface of the leaves of the lotus plant. This structure prevents the water spreading and instead round droplets form.

An active sunshade mounted externally.

This is technically no longer a problem. The main applications are privacy screens between offices, between operating theatres, and places where normal louvre blinds cannot be fitted.

In architecture and construction this is a façade design in which louvres are installed over a large area. The louvres can be made from a wide variety of materials, but wood, metal and glass are common choices.

Abbreviation for low-emissivity glass. The low emissivity is achieved with an ultra-thin metallic coating that considerably reduces the radiation losses from the glass surface.

A low E glass is an insulating unit in which the inside face of the inner pane (i.e. in the cavity) is coated with an ultra-thin layer of a noble metal (selective layer) which considerably reduces the loss of energy. The most important criteria for assessing a low E glass is the total energy transmittance (g-value) and the thermal transmittance of the glass (Ug).

Glass for applications where optical properties are relevant. Low-iron glass is suitable for façade and internal glazing where a high degree of transparency is desired. Eliminating iron oxides from the glass melt considerably reduces the typical, slightly greenish tint of glass. Well-known trade names: “Optiwhite”, “Diamant”.

The bottommost member in a trussed girder. In single-span girders the lower chord is loaded only in tension. A very slender member is therefore possible because it does not have to satisfy stability criteria.

The remuneration agreed for carrying out certain construction or other works without verification of the exact quantities used in the individual measures performed. Such a price can be agreed for an entire structure, but also just for a group of individual works specified in the contract.

Lustre colours are applied to the surface of the glass with a brush and fired in a reduced-oxygen atmosphere. Lustre colours are less durable than reduction colours.