| i beam | timber beam or steel girder constructed so that, in cross-section, it resembles a capital letter 'I' |
| impermeable surface | an artificial non-porous surface that generates a surface water runoff after rainfall. |
| indoor air quality (iaq) | the cleanliness or health effects of air in a building is affected by the amount of compounds released into the space by various materials, carbon dioxide levels, and microbial contaminants. iaq is heavily influenced by both choice of building materials and ventilation rates. |
| infiltration trench | a trench, usually filled with stone, designed to promote infiltration of surface water to the ground. |
| infiltration trenches and filter drains | infiltration trenches are stone filled reservoirs to which stormwater runoff is diverted and from which the water gradually infiltrates into the ground. filter strips, gullies or sump pits can be incorporated at inflow points to remove excess solids. filter drains are similar to infiltration trenches but have a perforated pipe running through them. they are widely used by highway authorities for draining roads and help to slow down runoff water en route towards the receiving watercourse. they allow storage and filtration of water before the discharge point. pollutant removal is by absorption, filtering and microbial decomposition in the surrounding soil. |
| infiltration trenches and filter drains | infiltration trenches are stone filled reservoirs to which stormwater runoff is diverted and from which the water gradually infiltrates into the ground. filter strips, gullies or sump pits can be incorporated at inflow points to remove excess solids. filter drains are similar to infiltration trenches but have a perforated pipe running through them. they are widely used by highway authorities for draining roads and help to slow down runoff water en route towards the receiving watercourse. they allow storage and filtration of water before the discharge point. pollutant removal is by absorption, filtering and microbial decomposition in the surrounding soil. |
| infiltration | the uncontrolled movement of outdoor air into the interior of a building through cracks and gaps. the gaps are usually found around walls, joints, windows, doors, roofs etc. |
| infiltration | the uncontrolled movement of outdoor air into the interior of a building through cracks and gaps. the gaps are usually found around walls, joints, windows, doors, roofs etc. |
| insulation batt | a semi rigid block of insulation. |
| intelligent buildings | buildings designs featuring extensive use of sensors, microprocessor controls, and automated systems and able to detect, diagnose, and control the response to varying environmental conditions or operational requirements. also called smart buildings. |
| interstitial condensation | interstitial condensation is condensation that occurs within a building element. it can be very harmful if interstitial condensation occurs on surfaces within the structure, as this can lead to the rot of timber or oxidation of metal surfaces, and other problems. there are many instances when condensation can form on the surface or interface of two materials without causing problems i.e. the cavity side of an external brick or block leaf |
| iso 9000 and iso 14000 | the international organisation for standardisation (iso) is a worldwide federation of national standards bodies. iso 9000 and iso 14000 are families of standards and guidelines relating to management systems. iso 9000 is associated with quality management. iso 14000 is associated with environmental management. |