Annex C: Glossary

  1. Glossary

    Glossary

    The definitions given below are for the purposes of this document only, and are not intended to be rigorous. Fuller definitions of the various acoustical terms are to be found in the relevant British Standards listed in Annex D. Absorption Conversion of sound energy to heat, often by the use of a porous material. Absorption coefficient A quantity characterising the effectiveness of a sound absorbing surface. The proportion of sound energy absorbed is given as a number between zero (for a fully reflective surface) and one (for a fully absorptive surface). Note that sound absorption coefficients determined from laboratory measurements may have values slightly larger than one. See BS EN 20354:1993. Absorptive material Material that absorbs sound energy. Airborne sound Sound propagating through the air. Airborne sound insulation Sound insulation that reduces transmission of airborne sound between buildings or parts of buildings. Air path A direct or indirect air passage from one side of a structure to the other. Caulking Process of sealing joints. Cavity stop A proprietary product or material such as mineral wool used to close the gap in a cavity wall. Ctr The correction to a sound insulation quantity (such as DnT,w) to take account of a specific sound spectrum. See BS EN ISO 717-1:1997. dB (See decibel) Decibel (dB) The unit used for many acoustic quantities to indicate the level with respect to a reference level. Density Mass per unit volume, expressed in kilograms per cubic metre(kg/m3). Direct transmission The process in which sound that is incident on one side of a building element is radiated by the other side. DnT The difference in sound level between a pair of rooms, in a stated frequency band, corrected for the reverberation time. See BS EN ISO 140-4:1998. DnT,w A single-number quantity which characterises the airborne sound insulation between rooms. See BS EN ISO 717-1:1997. DnT,w + Ctr A single-number quantity which characterises the airborne sound insulation between rooms using noise spectrum no. 2 as defined in BS EN ISO 717-1:1997. See BS EN ISO 717-1:1997. Dynamic stiffness A parameter used to describe the ability of a resilient material or wall tie to transmit vibration. Specimens with high dynamic stiffness (dynamically ‘stiff’) transmit more vibration than specimens with low dynamic stiffness (dynamically ‘soft’). See BS EN 29052-1:1992 for resilient materials. See BRE Information Paper IP 3/01 for wall ties. Flanking element Any building element that contributes to sound transmission between rooms in a building that is not a separating floor or separating wall. Flanking transmission Sound transmitted between rooms via flanking elements instead of directly through separating elements or along any path other than the direct path. Floating floor A floating floor consists of a floating layer and resilient layer (see also resilient layer and floating layer). Floating layer A surface layer that rests on a resilient layer and is therefore isolated from the base floor and the surrounding walls (see also resilient layer). Framed wall A partition consisting of board or boards connected to both sides of a wood or metal frame. Frequency The number of pressure variations (or cycles) per second that gives a sound its distinctive tone. The unit of frequency is the Hertz (Hz). Frequency band A continuous range of frequencies between stated upper and lower limits (see also octave band and one-third octave band). Hertz (Hz) The unit of the frequency of a sound (formerly called cycles per second). Impact sound Sound resulting from direct impact on a building element. Impact sound insulation Sound insulation which reduces impact sound transmission from direct impacts such as footsteps on a building element. Independent ceiling A ceiling which is fixed independently of a separating floor or an internal floor (see separating floor and internal floor). Internal floor Any floor that is not a separating floor (see separating floor). Intermediate landing A landing between two floors (see also landing). Internal wall Any wall that does not have a separating function. Isolation The absence of rigid connections between two or more parts of a structure. Landing A platform or part of floor structure at the end of a flight of stairs or ramp. LnT The impact sound pressure level in a stated frequency band, corrected for the reverberation time. See BS EN ISO 140-7:1998. LnT,w A single-number quantity used to characterise the impact sound insulation of floors. See BS EN ISO 717-2:1997. Mass per unit area Mass per unit area is expressed in terms of kilograms per square metre (kg/m²). Noise Noise is unwanted sound. Octave band A frequency band in which the upper limit of the band is twice the frequency of the lower limit. One-third octave band A frequency band in which the upper limit of the band is 2^1/3 times the frequency of the lower limit. Rw A single-number quantity which characterises the airborne sound insulation of a material or building element in the laboratory. See BS EN ISO 717-1:1997. Resilient layer A layer that isolates a floating layer from a base floor and surrounding walls. Reverberation The persistence of sound in a space after a sound source has been stopped. Reverberation time The time, in seconds, taken for the sound to decay by 60dB after a sound source has been stopped. Separating floor Floor that separates flats or rooms for residential purposes. Separating wall Wall that separates adjoining dwelling-houses, flats or rooms for residential purposes. Sound pressure level A quantity related to the physical intensity of a sound. Sound reduction index (R) A quantity, measured in a laboratory, which characterises the sound insulating properties of a material or building element in a stated frequency band. See BS EN ISO 140-3:1995. Spectrum The composition of a particular sound in terms of separate frequency bands. Structure-borne sound Sound which is carried via the structure of a building. UKAS United Kingdom Accreditation Service. ΔLw The measured improvement of impact sound insulation resulting from the installation of a floor covering or floating floor on a test floor in a laboratory. See BS EN ISO 717-2:1997.  

    • 0.1 Requirement E1 0.1 Requirement E1
    • 0.2 Requirement E2(a) 0.2 Requirement E2(a)
    • 0.3 Requirement E2(b) 0.3 Requirement E2(b)
    • 2.1 Types of separating wall 2.1 Types of separating wall
    • 2.2 Wall type 1.1 2.2 Wall type 1.1
    • 2.3 Wall type 1.2 2.3 Wall type 1.2
    • 2.4 Wall type 1.3 2.4 Wall type 1.3
    • 2.5 Wall type 1 - external cavity wall with masonry inner leaf 2.5 Wall type 1 - external cavity wall with masonry inner leaf
    • 2.6 Wall type 1 - bonded junction - masonry inner leaf of external cavity wall with solid separating wall 2.6 Wall type 1 - bonded junction - masonry inner leaf of external cavity wall with solid separating wall
    • 2.7 Wall type 1 - tied junction - external cavity wall with internal masonry wall 2.7 Wall type 1 - tied junction - external cavity wall with internal masonry wall
    • 2.8 Wall type 1 - position of openings in masonry inner leaf of external cavity wall 2.8 Wall type 1 - position of openings in masonry inner leaf of external cavity wall
    • 2.9 Wall type 1 - external cavity wall with timber frame inner leaf 2.9 Wall type 1 - external cavity wall with timber frame inner leaf
    • 2.10 Wall type 1 - internal timber floor 2.10 Wall type 1 - internal timber floor
    • 2.11 Wall type 1 - internal concrete floor 2.11 Wall type 1 - internal concrete floor
    • 2.12 Wall type 1 - concrete ground floor 2.12 Wall type 1 - concrete ground floor
    • 2.13 Wall type 1 - ceiling and roof junction 2.13 Wall type 1 - ceiling and roof junction
    • 2.14 External cavity wall at eaves level 2.14 External cavity wall at eaves level
    • 2.15 Wall type 2.1 2.15 Wall type 2.1
    • 2.16 Wall type 2.2 2.16 Wall type 2.2
    • 2.17 Wall type 2.3 2.17 Wall type 2.3
    • 2.18 Wall type 2.4 2.18 Wall type 2.4
    • 2.19 Wall types 2.1 and 2.2 - external cavity wall with masonry inner leaf 2.19 Wall types 2.1 and 2.2 - external cavity wall with masonry inner leaf
    • 2.20 Wall types 2.3 and 2.4 - external cavity wall with masonry inner leaf - stagger 2.20 Wall types 2.3 and 2.4 - external cavity wall with masonry inner leaf - stagger
    • 2.21 Wall type 2 - tied junction - external cavity wall with internal masonry wall 2.21 Wall type 2 - tied junction - external cavity wall with internal masonry wall
    • 2.22 Wall type 2 - external cavity wall with timber frame inner leaf 2.22 Wall type 2 - external cavity wall with timber frame inner leaf
    • 2.23 Wall type 2 - internal timber floor 2.23 Wall type 2 - internal timber floor
    • 2.24 Wall type 2 - internal concrete floor and concrete ground floor 2.24 Wall type 2 - internal concrete floor and concrete ground floor
    • 2.25 Wall type 2 - ceiling and roof junction 2.25 Wall type 2 - ceiling and roof junction
    • 2.26 External cavity wall at eaves level 2.26 External cavity wall at eaves level
    • 2.27 Wall type 3.1 with independent composite panels 2.27 Wall type 3.1 with independent composite panels
    • 2.28 Wall type 3.1 with independent plasterboard panels 2.28 Wall type 3.1 with independent plasterboard panels
    • 2.29 Wall type 3.2 with independent composite panels 2.29 Wall type 3.2 with independent composite panels
    • 2.30 Wall type 3.3 with independent composite panels 2.30 Wall type 3.3 with independent composite panels
    • 2.31 Wall type 3 - external cavity wall with masonry inner leaf 2.31 Wall type 3 - external cavity wall with masonry inner leaf
    • 2.32 Wall type 3 - external cavity wall with internal timber wall 2.32 Wall type 3 - external cavity wall with internal timber wall
    • 2.33 Wall type 3 - internal timber floor 2.33 Wall type 3 - internal timber floor
    • 2.34 Wall types 3.1 and 3.2 - internal concrete floor 2.34 Wall types 3.1 and 3.2 - internal concrete floor
    • 2.35 Wall types 3.1 and 3.2 - ceiling and roof junction 2.35 Wall types 3.1 and 3.2 - ceiling and roof junction
    • 2.36 External cavity wall at eaves level 2.36 External cavity wall at eaves level
    • 2.37 Wall type 4.1 2.37 Wall type 4.1
    • 2.38 Wall type 4 - external cavity wall with timber frame inner leaf 2.38 Wall type 4 - external cavity wall with timber frame inner leaf
    • 3.1 Types of separating floor 3.1 Types of separating floor
    • 3.2 Ceiling treatments A, B and C 3.2 Ceiling treatments A, B and C
    • 3.3 Floor type 1.1C - floor type 1.1 with ceiling treatment C 3.3 Floor type 1.1C - floor type 1.1 with ceiling treatment C
    • 3.4 Floor type 1.2B - floor type 1.2 with ceiling treatment B 3.4 Floor type 1.2B - floor type 1.2 with ceiling treatment B
    • 3.5 Floor type 1.2B - external cavity wall with masonry inner leaf 3.5 Floor type 1.2B - external cavity wall with masonry inner leaf
    • 3.6 Floor type 1 - floor penetrations 3.6 Floor type 1 - floor penetrations
    • 3.7 Floor type 1.1C - wall type 1 3.7 Floor type 1.1C - wall type 1
    • 3.8 Floor type 1.2B - wall type 1 3.8 Floor type 1.2B - wall type 1
    • 3.9 Floor type 1.1C and 1.2B - wall type 2 3.9 Floor types 1.1C and 1.2B - wall type 2
    • 3.10 Floor type 1.1C - wall type 3.1 and 3.2 3.10 Floor type 1.1C - wall types 3.1 and 3.2
    • 3.11 Floating floors (a) and (b) 3.11 Floating floors (a) and (b)
    • 3.12 Floor type 2.1C(a) - floor type 2.1 with ceiling treatment C and floating floor (a) 3.12 Floor type 2.1C(a) - floor type 2.1 with ceiling treatment C and floating floor (a)
    • 3.13 Floor type 2.1C(b) - floor type 2.1 with ceiling treatment C and floating floor (b) 3.13 Floor type 2.1C(b) - floor type 2.1 with ceiling treatment C and floating floor (b)
    • 3.14 Floor type 2.2B(a) - floor type 2.2 with ceiling treatment B and floating floor (a) 3.14 Floor type 2.2B(a) - floor type 2.2 with ceiling treatment B and floating floor (a)
    • 3.15 Floor type 2.2B(b) - floor type 2.2 with ceiling treatment B and floating floor (b) 3.15 Floor type 2.2B(b) - floor type 2.2 with ceiling treatment B and floating floor (b)
    • 3.16 Floor type 2 - external cavity wall with masonry internal leaf 3.16 Floor type 2 - external cavity wall with masonry internal leaf
    • 3.17 Floor type 2 - floor penetrations 3.17 Floor type 2 - floor penetrations
    • 3.18 Floor types 2.2B(a) and 2.2B(b) - wall type 1 3.18 Floor types 2.2B(a) and 2.2B(b) - wall type 1
    • 3.19 Floor types 2.1C - wall types 3.1 and 3.2 3.19 Floor types 2.1C - wall types 3.1 and 3.2
    • 3.20 Floor type 3.1A 3.20 Floor type 3.1A
    • 3.21 Floor type 3 - floor penetrations 3.21 Floor type 3 - floor penetrations  
    • 3.22 Floor type 3 - wall type 1 3.22 Floor type 3 - wall type 1
    • 3.23 Floor type 3 - wall type 2 3.23 Floor type 3 - wall type 2
    • 4.1 Treatments for material change of use 4.1 Treatments for material change of use
    • 4.2 Wall treatment 1 4.2 Wall treatment 1
    • 4.3 Floor treatment 1 4.3 Floor treatment 1
    • 4.4 Floor treatment 1 - high window head detail 4.4 Floor treatment 1 - high window head detail
    • 4.5 Floor treatment 1 - wall treatment 1 4.5 Floor treatment 1 - wall treatment 1
    • 4.6 Floor treatment 2 4.6 Floor treatment 2
    • 4.7 Floor treatment 2 - wall treatment 1 4.7 Floor treatment 2 - wall treatment 1
    • 4.8 Stair treatment 4.8 Stair treatment
    • 4.9 Floor penetrations 4.9 Floor penetrations
    • 5.1 Internal wall type A 5.1 Internal wall type A
    • 5.2 Internal wall type B 5.2 Internal wall type B
    • 5.3 Internal wall type C 5.3 Internal wall type C
    • 5.4 Internal wall type D 5.4 Internal wall type D
    • 5.5 Internal floor type A 5.5 Internal floor type A
    • 5.6 Internal floor type B 5.6 Internal floor type B
    • 5.7 Internal floor type C 5.7 Internal floor type C
    • 6.1 Ceiling void and roof space 6.1 Ceiling void and roof space
    • A1 Block and mortar dimensions A1 Block and mortar dimensions
    • A2 Beam and block floor dimensions A2 Beam and block floor dimensions
    • Table 0.1a Dwelling-houses and flats - performance standards for separating walls, separating floors, and stairs that have a separating function Table 0.1a Dwelling-houses and flats - performance standards for separating walls, separating floors, and stairs that have a separating function
    • Table 0.1b Rooms for residential purposes - performance standards for separating walls, separating floors, and stairs that have a separating function Table 0.1b Rooms for residential purposes - performance standards for separating walls, separating floors, and stairs that have a separating function
    • Table 0.2 Laboratory values for new internal walls and floors within dwelling-houses, flats and rooms for residential purposes, whether purpose built or formed by material change of use Table 0.2 Laboratory values for new internal walls and floors within dwelling-houses, flats and rooms for residential purposes, whether purpose built or formed by material change of use
    • Table 2.1 Separating wall junctions reference table Table 2.1 Separating wall junctions reference table
    • Table 3.1 Separating floor junctions reference table Table 3.1 Separating floor junctions reference table
    • Table 7.1 Absorption coefficient data for common materials in buildings Table 7.1 Absorption coefficient data for common materials in buildings
    • Table 7.2 Example calculation for an entrance hall (Method B) Table 7.2 Example calculation for an entrance hall (Method B)
    • Table A1 Blocks laid flat Table A1 Blocks laid flat
    • Table A2 Blocks laid on edge Table A2 Blocks laid on edge