LC Construction Studies flashcards

35 cards. Read the term and the definition here. The deck at the top of this page is optional.

Plot ratio

The ratio of total gross floor area of a building to the area of its site. Local plans set maximum plot ratios to control density and building bulk.

Site survey

A measured record of a site's boundaries, levels, contours, existing structures, services, and access. It forms the base drawing for all subsequent design work.

Safe bearing capacity

The allowable pressure that ground can carry without excessive settlement or shear failure. It is established by ground investigation and determines foundation type and size.

Exempted development

Development that does not require planning permission because it falls within stated limits, such as small domestic extensions. It must still comply with building regulations.

Thermal conductivity

The rate at which heat passes through a material, measured in W/m·K. Lower values indicate better insulation, and it is used to calculate thermal resistance of a layer.

U-value

The overall rate of heat transfer through a building element, in W/m²·K. It is the reciprocal of the sum of all layer resistances plus surface resistances.

Concrete strength class

A designation such as C25/30 giving characteristic cylinder and cube strengths in N/mm² at 28 days. It guides structural specification and mix design.

Damp-proof course

An impermeable layer built into a wall to stop moisture rising by capillary action. It is lapped with the damp-proof membrane under the ground floor.

Anisotropic timber

Timber has different strength and shrinkage properties along and across the grain. It is strongest parallel to grain and shrinks most in the tangential direction.

Cavity wall construction

Two masonry leaves separated by a cavity, tied together with wall ties. The cavity may hold insulation and drains moisture, with weep holes above flashings.

Raft foundation

A reinforced concrete slab spread across the whole footprint, distributing load over weak or variable ground. It is used where strip foundations would settle unevenly.

Cold roof

A roof with insulation at ceiling level and a ventilated void above it. Ventilation removes moisture that would otherwise condense on the cold underside of the deck.

Fire compartmentation

The division of a building into fire-resisting compartments by walls, floors, and doors. It limits fire and smoke spread and protects escape routes.

Stair rise and going

The vertical rise and horizontal tread of a stair. Two rises plus one going should total roughly 550–700 mm for comfortable, safe use.

Bending moment formula

For a simply supported beam with uniform load w over span L, the maximum bending moment is wL²/8 at midspan. It sets the required section modulus.

Bending stress equation

Bending stress equals bending moment divided by elastic section modulus, σ = M ÷ Z. It must stay below the design strength of the material.

Slenderness ratio

Effective length divided by radius of gyration. Higher values reduce compressive resistance, so columns need restraint about both axes.

Triangulation for stability

Bracing members forming triangles prevent a rectangular frame from distorting. Braced frames and shear walls resist lateral loads such as wind.

Dead and live loads

Dead load is the permanent self-weight of construction; live load is the imposed occupancy and use load. Both are combined with partial safety factors in design.

Embodied carbon

Total greenhouse gas emissions associated with extracting, manufacturing, transporting, constructing, and disposing of building materials. It is assessed by life cycle assessment.

Thermal bridging

Localised high heat loss where insulation is interrupted, such as at junctions and lintels. Accredited details and continuous insulation reduce it.

Airtightness testing

A pressure test measuring air leakage at 50 Pa, expressed as air changes per hour or m³/h·m². It identifies gaps that increase heat loss and condensation risk.

Sustainable drainage systems

Techniques that manage rainwater close to where it falls through infiltration, attenuation, and flow control. They reduce flood risk and pollution compared with direct connection.

Overheating risk

The likelihood that internal temperatures exceed comfort limits, driven by solar gain, glazing area, orientation, and ventilation. Thermal mass and shading reduce it.

Coefficient of performance

The ratio of heat delivered by a heat pump to the electrical energy consumed. Lower flow temperatures and well-insulated buildings raise the COP.

Mechanical ventilation with heat recovery

A balanced system that extracts stale air and supplies fresh air while transferring heat between the two streams. It typically recovers 70–90% of exhaust heat.

Rainwater harvesting

Collection and storage of roof runoff for non-potable uses such as WC flushing and irrigation. It requires filtration, storage, and a backup mains supply.

Building energy rating

A certificate rating a building's energy performance on a defined scale. It is based on fabric, services efficiency, renewables, and assessed energy demand.

Thermal resistance formula

Resistance R equals thickness d divided by thermal conductivity λ, in m²·K/W. Layer resistances are summed with surface resistances to find the U-value.

Fabric heat loss

Heat lost through the building envelope, calculated as the sum of U-value times area for each element, multiplied by the temperature difference.

Interstitial condensation

Condensation forming inside a construction when water vapour reaches a layer below dew point. A vapour control layer on the warm side and ventilation reduce the risk.

Degree days

A measure of how cold a climate is over a season, based on the difference between a base temperature and mean outdoor temperature. It estimates heating energy use.

Orthographic projection

A method of drawing separate plan, elevation, and section views of a building. First-angle and third-angle conventions arrange the views differently on the sheet.

Drawing scale notation

A ratio such as 1:50 stating that one unit on the drawing represents fifty units on the building. Details use larger scales than site plans.

Title block

A panel on every drawing recording project name, drawing number, scale, revision, date, and author. It makes drawings traceable and controls revisions.