Glossary of Common Terms (A – E)
Whether you’re baffled about BIM or confused about condensation, this is the post for you!
Our industry is one that throws around acronyms (and the word ‘value’) like there’s no tomorrow. We understand that this can become both overwhelming and confusing, especially when reading alongside other technical terms, and that’s why we’ve created this helpful glossary.
We’re starting off with terms beginning with letters A through E. Check back over the next few weeks for the rest of the alphabet.
If you think we’ve missed something important, please do leave a comment and we will do our best to help. You might also want to take a look at this handy booklet: Everything you wanted to know about insulation, but were afraid to ask.
Hint: Use CTRL + F to search for a specific term!
ACD – Approved / Accredited Construction Details are a set of standardised construction details developed by regulators to deal with the issue of heat loss / gain and other issues.
Acoustic Insulation – A product used to impede the transfer of sound, either via airborne or impact transfer. Typically internal constructions within buildings are required to utilise acoustic insulation products to aid in minimising the transfer of sound from one adjacent room into another. “Approved Document E” and “Part E – Robust Details” contain further information on common methods of controlling the transfer of sound in buildings.
Air Tightness – The uncontrolled leakage of air from a building through cracks, unsealed penetrations or interfaces between different building elements.
Ambient – When referring to heat, temperature, etc. ambient describes the surrounding conditions. i.e. the Ambient temperature is the average temperature surrounding a material.
Ballast – A ballast layer is typically used in warm or inverted roofs down to weigh down the insulation or waterproofing system. Common items used to form ballast layers include concrete paving slabs, round washed pebbles or a green roof system (e.g. plants and growing medium such as soil). The weight of the ballast required is dependent on results from a wind uplift calculation.
BER – Building Emission Rate details the energy performance of a building calculated following the NCM (National Calculation Methodology) eg SBEM. These measurements will be compared to the TER to define whether a building passes building regulations.
BIM – Building Information Modelling is a way of managing all the information required for a construction project. This database is referred to as AIM (Asset Information Model). In accordance with the government’s ‘Construction Industry Strategy 2011’, all new public constructions should use Level 2 BIM from April 2016. Further information on BIM is available in our ‘BIM for the Baffled’ series.
Blowing Agent – A substance used during the manufacture of cellular foam insulation products. These agents are typically used to enhance the thermal performance of the finished product by filling the cells within the insulation with a low thermal conductivity gas. The Kooltherm and Therma ranges of insulation products we produce use Pentane based blowing agents with zero Ozone Depletion Potential and low Global Warming Potential (GWP).
BPEO – Best Practice Environmental Option includes initiatives such as Kingspan’s Waste Collection Service.
BREEAM – An environmental assessment and rating system for buildings. It uses recognised measures of performance, which are set against established benchmarks, to evaluate a building’s specification, design, construction and use.
Breathability – A non–scientific term used when discussing moisture transport through a construction.
Building Control Bodies – Public and private organisations that assess and verify compliance with building regulations and standards. Building envelope separates the internal and external environments, such as a roof or walls. In order to provide the adequate protection against heat leakage, the building envelope should have as few thermal bridges and unintended gaps a possible.
Built-Up Roof – A roof made up of layers of building elements, typically roofing felt and asphalt with waterproofing layer and gravel on top.
Butt Joints – A joint made from two materials placed end to end without overlapping. They are used in pipe insulation and when laying loose boards on a floor or roof.
Carrier Membrane – This is a membrane typically used to provide a suitable substrate for laying another product, i.e. such as for a liquid applied waterproofing system to be applied onto. Refer to individual waterproofing manufacturers for specific recommendations on when such layers are required, and if they are what is used for them.
Cavity Closers – Insulated extrusions for closing wall cavities at openings such as window reveals and door reveals. Cavity closers reduce heat transfer, avoiding thermal bridging, condensation and mould growth. They can even be used to pre–form openings when window and door frames are fitted later. Kingspan Kooltherm Cavity Closer and Kingspan Thermabate are examples.
CE Label – This shows compliance with EN and CEN standards.
Cellular Insulation – Insulation such as polyurethane, polyisocyanurate and phenolic insulation, which is made up of small individual cells.
Centres of Rafters / Joists – The centres of joists or rafters are measured by taking the centre point of one joist/rafter to the centre point of the following adjacent joist/rafter. Timber joists and rafters are traditionally located at 400 mm, 450 mm or 600 mm centres, or in refurbishments sometimes their imperial approximate equivalents of 16, 18 and 24 inches.
Closed Cell Insulation – This has a more compact and denser structure than open cell insulation. As a result, it decreases the ingress of moisture and is more resistant to heat transmission. Insulation with a closed cell structure is also more resistant to flood damage. Because of its low water take–up, closed cell insulation panels recover from immersion in flood water more quickly than mineral fibre insulations for example.
Cold Bridging – A type of thermal bridging that occurs when a structural element of a building lets heat flow through it because it has a lower thermal resistance than other components in the construction.
Compressive Creep – The measure of how much a material changes under long–term load. Heavy duty insulation materials ideally have a low compressive creep so they have a suitable durability in heavy duty applications.
Compressive Strength – A material’s ability to maintain its structural integrity when compressed. Insulation products with a high compressive strength such as Kingspan Styrozone are used for heavy duty floors and roofs.
Condensation – The conversion of a substance (typically water when referenced in the construction industry) from the vapour state to a liquid due to a change in temperature or pressure, e.g. such as warm moist air hitting a cold surface causing: a reduction in temperature of the air; and moisture vapour to condense out of the air. The two main occurrences of condensation are:
- Surface Condensation which can lead to mould and staining through its formation on the visible surface of a material.
- Interstitial Condensation occurs between the layers of a construction. This type of condensation can both reduce the effectiveness of insulation components and reduce their lifespan.
CRA – Condensation Risk Analysis is performed on the construction elements of a building, taking into account the order in which they appear, and the building’s geographical location. Kingspan’s Technical department present CRA with U–value calculations.
DER – Dwelling Emission Rate details the energy performance of a building calculated using SAP. These measurements will be compared to the TER to define whether a dwelling passes building regulations.
DFEE – Dwelling Fabric Energy Efficiency. This is compared to the TFEE to comply with building regulations in England.
DPM – A Damp Proof Membrane is used with some insulations to prevent moisture building up on the insulation layer.
Emissivity – The ‘shininess’ of a material. A high emissivity will increase the amount of heat transfer through radiation. It is measured in watts per square metre (W/m2) in relation to an ideal black surface as a ratio from 0 to 1. The closer to 0 the emissivity ratio, the lower the emission of heat as radiation. A foil facing on an insulation board allows a low emissivity to be taken when calculating the thermal resistance of an unventilated airspace eg. in a cavity wall construction.
EPC – An Energy Performance Certificate is required upon completion of a dwelling in accordance with the English, Scottish and Welsh building standards. This necessitates energy calculations eg. SAP or SBEM. They measure on a scale of A–G, the green to red scale covers the energy efficiency rating, while the blue to grey scale measures the environmental impact rating of the construction.
EPS – Expanded Polystyrene is a light rigid foam insulation that has low thermal conductivity and high impact resistance.
EWI – External Wall Insulation – insulation installed on the outside or cold side of a wall.
Share this blog post with your friends and colleagues by clicking on the social media icons below.