LC Construction Studies key terms

The structured investigation of a plot before design begins, covering access, ground conditions, drainage, orientation, services, planning constraints and neighbouring buildings, so that opportunities and risks inform the brief.

Formal consent from the local planning authority allowing a proposed development. It assesses land use, density, design, amenity and access rather than structural or fire safety, which are controlled separately.

Statutory consent confirming that a design meets minimum standards for structure, fire safety, weathertightness, ventilation, drainage, energy use and accessibility. It is distinct from planning permission and is often certified by a private approved inspector.

The recorded heights across a plot, referenced to a fixed datum such as ordnance level or a temporary benchmark, used to set floor levels, falls, drainage and cut-and-fill volumes.

Controlled slopes expressed as a ratio, percentage or angle, used to shed rainwater from roofs and paving and to drive drainage by gravity at a self-cleansing velocity.

The rate at which water soaks through subsoil, tested on site to size soakaways and septic drainage fields. Slow or clay-rich ground may demand storage, pumping or an alternative discharge route.

An excavated inspection hole that reveals soil strata, groundwater level and bearing capacity, allowing the engineer to judge foundation type and depth before construction starts.

Thermal transmittance of a building element in watts per square metre per kelvin. Lower values mean better insulation; it is calculated from the resistance of each layer plus surface resistances.

A localised path of high heat flow where geometry or a more conductive material bypasses the insulation, such as a balcony slab or a steel lintel, causing cold spots and possible condensation.

The linear thermal transmittance of a junction, in watts per metre per kelvin, quantifying the extra heat loss caused by a thermal bridge beyond the U-values of the adjoining elements.

The capacity of a material to absorb and later release heat, slowing temperature swings. Dense materials such as concrete and masonry help stabilise internal conditions when exposed to the room.

Heat entering a building from solar radiation through glazing and absorbed by the fabric. Useful in winter but a major cause of overheating in summer unless shading or glazing choice controls it.

The likelihood that internal temperatures exceed comfort thresholds in summer, assessed from glazing area, orientation, shading, ventilation strategy, occupancy and internal heat gains.

A measure of uncontrolled air leakage through the building envelope, expressed in cubic metres per hour per square metre at a reference pressure and tested by a blower-door test.

A low-permeability membrane placed on the warm side of insulation to restrict water vapour diffusion into the structure, reducing the risk of interstitial condensation and timber decay.

Moisture forming inside a construction where vapour reaches a layer cold enough to condense. It is controlled by correct layer order, vapour barriers, ventilation and breathable outer layers.

Material of low thermal conductivity used to resist heat flow. Performance depends on thickness, continuity, moisture content and whether the insulation is placed inside, within or outside the structure.

The outer skin fixed over a structural frame, providing weather resistance and appearance. It must accommodate movement, allow back ventilation or drainage, and resist wind load and impact.

A cladding principle in which an outer layer sheds most rain while a drained and ventilated cavity behind removes any that penetrates, with an inner leaf giving airtightness.

A wall of two leaves separated by a gap, tied together with wall ties. The cavity sheds water and can hold insulation, while the inner leaf carries load and supports the floor and roof.

A corrosion-resistant connector that transfers wind load between the leaves of a cavity wall while allowing the outer leaf to move and the cavity to drain.

A horizontal member spanning an opening in a wall to carry the load above. It may be timber, steel, reinforced concrete or prestressed masonry, sized for bending and bearing.

An isolated reinforced concrete base that spreads the load of a column onto suitable ground. Size and depth depend on bearing capacity and the position of the water table.

The permanent, self-weight of the structure and fixed finishes, including walls, floors, roof covering and services. It is estimated from material densities and volumes.

A variable load applied in service, such as occupants, furniture, stored goods, snow or wind. Design values come from codes that set characteristic loads for each occupancy type.

The continuous route by which gravity and lateral forces travel from their point of application through slabs, beams, columns, walls and foundations into the ground without interruption.

The structure's ability to resist horizontal forces such as wind and uneven loading, usually through bracing, shear walls, moment frames or diaphragm action of floors.

A measure of how prone a compression member is to buckling, comparing its effective length with its radius of gyration; higher values require greater restraint or larger sections.

Rapid ventilation by opening windows or vents to remove pollutants, moisture or heat quickly. It is a separate requirement from the continuous background ventilation needed for air quality.

A device that moves heat from a cooler source such as air or ground to a warmer space using a refrigeration cycle, delivering more heat energy than the electricity it consumes.

A design approach that manages rainwater close to where it falls using permeable surfaces, swales, basins and storage, reducing flood risk, pollution and load on public sewers.

The total greenhouse gas emissions associated with extracting, manufacturing, transporting, constructing and eventually disposing of building materials and components.

A drawing method in which parallel projectors meet the picture plane at right angles, producing plans, elevations and sections at true shape and to a stated scale.

A cut through a building showing the relationship of floors, walls, roof and foundations, with cut material distinguished from background by line weight and hatching.

The fixed ratio between a drawing and the real object, such as 1:50 for plans or 1:5 for details. It governs the level of information a drawing can reasonably convey.

A coordinated digital model of a building in which geometry and data are shared between disciplines, supporting clash detection, quantities, scheduling and whole-life information management.