Dictionary of Construction Terms
Dictionary of Construction Terms
The construction of a house is accompanied by many technical and construction terms that are often not easy to understand for someone who does not deal with the construction field on a daily basis.
In this dictionary, we have gathered basic terms used in the study, design and construction of a house, as well as concepts that are often found in technical drawings, specifications and construction work.
Each term is explained in a simple and understandable way, so that you can better understand the construction process, the structural elements of a house and the technical solutions applied in a modern building.
The dictionary of construction terms is constantly updated with new explanations, so that it is a useful guide for anyone interested in better understanding the language of construction and architecture.
| Terms | Explanation |
|---|---|
| Agricultural parcel | A tract of land located outside an approved town plan. In practice, the terms “agricultural parcel” and “land parcel” are often used interchangeably. The possibility of building depends on specific requirements (area, frontage on a road, date of creation, etc.). Each case must be assessed by an engineer to determine whether construction is permitted and under which conditions. |
| Building permit (construction permit) | The administrative approval that authorises the construction of a building. It is issued through the electronic system of the Technical Chamber of Greece (TEE), known as e-Permits, following the submission and review of the required studies. The permit defines the main planning parameters of the project, such as: • the position of the building within the plot • the permitted floor area and site coverage • the height of the building • the distances from the plot boundaries Once the permit has been issued, construction may legally begin. 👉 See what you should consider before starting construction. |
| Demolition permit | A permit required for the demolition of an existing structure. It is issued before a building is dismantled and defines the method and safety measures to be followed during the process. |
| Small-scale works permit | A permit covering limited works that do not require a full building permit, such as certain alterations, small structures or technical interventions. The exact works allowed are determined by the legislation currently in force. |
| Unbuilt area | The unbuilt area is the part of a plot that is not covered by a building. It allows natural light and ventilation and may be landscaped as a garden or courtyard. |
| Permit revision | The process of amending a building permit that has already been issued. A revision may be required when elements of the study change, such as: • planning parameters (floor area, coverage, height) • architectural design • structural or mechanical studies • project or owner details The revision is completed through the same electronic system used to issue the original permit. |
| Seismic separation joint | A seismic separation joint is the gap left between two buildings, or between sections of the same building, so that they can move independently during an earthquake. This reduces the risk of the buildings colliding and limits potential damage. |
| Distance D | Distance D is the minimum distance that must be maintained between a building and the boundaries of the plot. It is defined by the building regulations and usually depends on the height of the building. Its purpose is to ensure sufficient natural light, ventilation and separation between buildings. |
| Plot eligibility | Plot eligibility means that a building plot or land parcel meets the minimum requirements set by planning legislation (area, road frontage, etc.) in order to be developed. The applicable requirements vary depending on the area and the relevant planning regime. |
| Industrial zone | An industrial zone is an area designated through urban planning for the establishment of industrial activities. These areas mainly permit production facilities, warehouses and other related uses. |
| Organised industrial area (VI.PE.) | An organised industrial area is a designated zone where industrial and manufacturing activities are concentrated. It usually provides organised infrastructure such as a road network, drainage systems and shared public areas. |
| Land parcel (agricultural parcel) | A land parcel or agricultural parcel is a property located outside an approved town plan or outside the boundaries of a settlement. The possibility of building on such land is determined by specific rules for development outside the town plan, including minimum area, frontage on a legally recognised road and other restrictions provided by law. 👉 See also: Buying a building plot |
| GUP – General urban plan | The General Urban Plan is the main planning instrument for an area. It defines land uses, development zones, protected areas and the principal development guidelines of a municipality. |
| Construction project | A construction project is any structure created through building works, such as a residence, commercial building, warehouse or other construction. |
| Road | A road is a public space used for the movement of pedestrians and vehicles. Access to a legally recognised road is often a key requirement for a building plot or land parcel to be buildable. |
| Building outside the town plan | Construction carried out in areas outside an approved town plan or outside the boundaries of a settlement. The building conditions differ from those applying within planned areas, and a detailed assessment by an engineer is required to determine whether the land parcel meets the minimum requirements and is buildable. |
| Building inspector | An independent engineer selected by random draw through the electronic system of the Technical Chamber of Greece (TEE), who carries out inspections to verify that construction is being completed in accordance with the approved building permit. For residential buildings, two main inspections are usually carried out: • before the foundation concrete is poured • after construction has been completed Following each inspection, a report is prepared. Without the required inspections, the building permit process cannot be legally completed. 👉 See what to consider during the construction of your home to avoid issues during the inspection. |
| Clear height | The clear height of a space is the unobstructed internal distance from the finished floor to the ceiling. |
| Permit update | A process for amending a permit without materially changing the planning parameters of the building. It usually concerns minor adjustments or corrections to the submitted information. |
| Permitted floor area | The total number of square metres that may be constructed on a building plot or land parcel, calculated cumulatively across all floors of the building. The permitted floor area is determined by the floor area ratio and the planning characteristics of the property. |
| Permitted site coverage | Site coverage expresses the percentage of the plot that may be covered by the building at ground level. In other words, it is the footprint of the building in relation to the total area of the plot. The permitted site coverage is determined by the site coverage ratio and the planning characteristics of the property. |
| Semi-open space | A semi-open space is a roofed part of a building that remains open towards the unbuilt area on at least one side. It acts as a transitional space between the interior and exterior and contributes to natural ventilation, shading and protection from the weather. |
| EBI – Electronic building identity | A digital file containing all key information about a property, including permits, drawings, surface areas and declarations. It is required for property transfers and for the completion of the building permit process. |
| Ownership | The legal right to possess and use a property. |
| Public spaces | Areas intended for use by all citizens, such as roads, squares, pedestrian streets and public green spaces. |
| Building common areas | Areas within a building used by all owners, such as stairwells, entrances and other shared spaces. |
| Public-purpose areas | Areas designated for public facilities, such as schools, public services, hospitals or other public-benefit functions. Their location is determined through urban planning. |
| Building | A structure containing spaces intended for a specific use, such as residential or commercial use. |
| Maximum permitted height | The building height is the maximum height a building may have under the applicable planning conditions of the area. It is measured from ground level to the highest point of the structure, in accordance with the relevant building regulations. |
| Building permit studies | A series of technical studies prepared by engineers is required for the issuance of a building permit. The main studies include: • Architectural study – defines the form and functional layout of the building. • Structural study – calculates the load-bearing structure and the strength of the construction. • Mechanical and electrical study – covers the building’s mechanical and electrical installations. • KENAK energy study – calculates the energy performance of the residence. • Fire safety study – defines the required fire-protection measures, where applicable. These studies are submitted through the e-Permits system and form the basis for the issuance of the permit. |
| NOK (New Building Regulation) | The principal regulation governing building conditions in Greece. |
| Settlement | A group of residences that is administratively designated and has defined boundaries. |
| Buildability | Buildability is the legal ability of a building plot or land parcel to accommodate a building. For a property to be buildable, it must meet the planning requirements applicable in the area, such as minimum plot eligibility, access to a legally recognised road and the current building conditions. |
| Building line | The building line is the line up to which the building may extend towards the road. It therefore determines the position of the building within the plot in relation to the road. |
| Urban block | The area enclosed by roads within an approved town plan. |
| Building plot | A building plot is a parcel of land located within an approved town plan or within the boundaries of a settlement, which may be developed in accordance with the planning conditions of the area. Its development potential is determined by factors such as the floor area ratio, site coverage, height and distances from the boundaries. 👉 See what to consider before buying a building plot |
| Adjoining plot | A neighbouring plot that shares a boundary with another property. |
| Plot boundaries | The geometric boundaries of a property as shown on the topographic survey. |
| EPC – Energy performance certificate | A document indicating the energy efficiency class of a building. |
| Pedestrian street | A road intended exclusively for pedestrians. |
| Plot outline | The exact representation of the plot boundaries on the topographic survey. |
| Road width | The total width of a road, which affects building conditions and required setbacks. |
| Mandatory planting percentage | The percentage of the plot that must remain planted. |
| Front setback (prasia) | The front setback, also known as the prasia or front garden area, is the mandatory distance between the street planning line and the building line. This area normally remains unbuilt and is used for planting or landscaping. |
| Vertical extension | The construction of an additional floor above an existing building. |
| Horizontal extension | The horizontal expansion of a building at the same level. |
| Frontage | The length of the plot boundary that adjoins a road. |
| Street planning line | The street planning line is the boundary separating a building plot from the public space, usually the road. In certain cases, part of the plot may need to be ceded for the formation or widening of the road. |
| Structural adequacy | The ability of a building to withstand the applicable loads and remain structurally safe. |
| Floor area ratio (FAR) | The floor area ratio determines the total floor area of buildings that may be constructed on a plot. It is calculated by multiplying the area of the plot by the floor area ratio applicable in the area. Example: On a 500 m² plot with a floor area ratio of 0.4, a total floor area of 200 m² is permitted. |
| Building volume ratio | An index related to the maximum permitted volume of a building. |
| Town plan | The approved urban planning scheme of an area. |
| SCHOAP | The Spatial and Residential Organisation Plan for an Open City, which defines land uses and development in areas outside an approved town plan. |
| Mandatory open space | The part of the plot that must remain free of structures. |
| Existing building | A building that has already been constructed and exists either legally or without the required authorisation. |
| Permit tax documentation | During the building permit process, certain tax-related documents connected with the project must also be submitted, including project declarations and information required by the competent authorities to monitor the construction. |
| Building use | The purpose for which a building is used, such as a residence, shop or other use. |
| Project timeline | The project timeline describes the sequence and duration of the works, from the issuance of the permit through to the completion of construction. It supports effective planning and the coordination of contractors and suppliers. |
| Provision for a future storey | Where permitted by the floor area ratio (FAR), the structural and construction design can include provision from the outset for the future addition of another storey. |
| Building volume | The overall three-dimensional form created by the dimensions and geometry of a building. |
| TERMS | EXPLANATION |
|---|---|
| 3A | A mixture of aggregates (sand and gravel) with a specific particle-size distribution, mainly used as a sub-base in construction, in levelling layers, floor bases or beneath foundations. |
| Aggregates | Natural materials such as sand, gravel and crushed stone, used in the production of concrete and mortars and forming a basic component of almost every construction project. |
| Rafters | Rafters are the inclined timber elements of a roof that follow its slope and help support the roof covering, insulation and the remaining roof layers. They are usually connected to the main beams or the ridge beam and transfer loads to the supporting points. In roofs with exposed timber, the rafters may remain visible in the interior, creating a warmer, more natural and architecturally distinctive result. |
| Seismic design | Seismic design concerns the way a structure is designed so that it can withstand seismic actions. In Greece, buildings are designed in accordance with the applicable regulations and Eurocodes to ensure the safety and stability of the structure in the event of an earthquake. |
| Retaining wall | A structure, usually made of reinforced concrete, that retains soil at different levels when there is an elevation difference within the plot. |
| Drainage | A system for removing water from the ground or from structures, commonly applied around foundations, basements and areas where moisture accumulates. |
| Concrete test specimen | A concrete sample taken during concrete pouring and tested in a laboratory to confirm the strength and quality of the concrete. |
| Beam | A beam is a horizontal structural element that transfers the loads of the structure to columns or walls. Beams work together with slabs and form a key part of a building’s load-bearing structure. |
| Structural timber | Structural timber is timber used for load-bearing construction elements and graded according to specific strength classes. It is tested for its mechanical properties and moisture content to ensure the stability and durability of the structure over time. Specific strength classes are used in construction in accordance with the European standard EN 338, such as C24 or C30. These classes indicate the timber’s characteristic bending strength and mechanical properties. Structural timber is generally classified into categories such as: C18–C24 for standard construction C24–C30 for structures with higher strength requirements The timber also undergoes kiln drying to achieve a controlled moisture content. According to Eurocode 5, the moisture content of structural timber is associated with the so-called service classes: Service class 1: timber moisture content of up to approximately 12% (heated indoor spaces) Service class 2: moisture content of up to approximately 20% (covered but unheated spaces) Service class 3: moisture content above 20% (external conditions) Structural timber is kiln-dried so that its moisture content is reduced to controlled levels, usually approximately 10–14%. This low moisture content limits shrinkage and warping and contributes to the stability of the structure, while also significantly reducing the likelihood of fungi and other microorganisms developing. EasyGreen constructions use C30 strength-class Nordic Spruce structural timber with a controlled moisture content of approximately 12%, suitable for high-quality load-bearing structural elements. The structural timber is CE marked and classified in accordance with European standards (EN 14081 / EN 338). 👉 See what to look out for when building a timber house |
| Reinforcement mesh (welded wire mesh) | A steel reinforcement mesh used to strengthen concrete elements such as slabs and floors. |
| Lightweight concrete | Concrete with reduced weight, generally used in levelling layers or to create falls, mainly on flat roofs and floors where a lower load is required. |
| Exposed concrete | Concrete that remains without cladding or plaster and serves as the final architectural finish, creating an industrial or modern aesthetic. |
| Plaster (render) | A mortar coating applied to walls for protection, surface levelling and preparation before painting or another final finish. |
| Roof truss | A roof truss is a timber or steel structural element used to support a roof. It consists of members connected in a specific geometry so that the roof loads are transferred to the walls or the building’s other load-bearing elements. In timber houses, trusses are commonly used for the construction of tiled roofs. They may be closely spaced and covered internally with a suspended ceiling or, in special cases, left exposed when the roof forms part of the interior architecture. |
| Foundation | The foundation is the part of the structure that transfers the building loads to the ground. It forms the base that supports the entire load-bearing structure of the house. The correct foundation design depends on the weight of the building and the geotechnical characteristics of the soil. For this reason, the foundation is determined by the project’s structural design. Various foundation types are used in residential construction, such as footing beams or a raft foundation (radier). |
| Formwork | A temporary structure into which concrete is poured so that it takes the required shape until it hardens. |
| Mortar | A mixture of cement, sand and water used for plastering, masonry or other surface bonding and levelling works. |
| Rounded gravel | Larger-diameter rounded gravel used mainly for drainage or decorative applications in external areas. |
| Single-sided formwork | A type of formwork supported from one side only, generally used for walls or structures where access is not available from both sides. |
| Construction debris (excavation or demolition waste) | Materials resulting from excavation or demolition, such as soil, stones and construction remains, which are either removed from the site or used as fill. |
| Timber load-bearing structure (timber frame) | A timber load-bearing structure is a construction system in which the building frame is made of structural timber. The frame’s main components are vertical and horizontal timber elements that form the walls, floors and roof of the house. The building loads are transferred through these elements to the foundation. This system is widely used in many countries because of its high strength, good seismic performance and the high level of construction precision it allows. |
| Formwork | A temporary structure made of timber or metal elements into which concrete is poured until it hardens and acquires its final shape. |
| Reinforced concrete | Concrete reinforced with steel bars to provide greater tensile and bending strength, used in the load-bearing elements of structures. |
| Footing | A local widening of the foundation beneath columns or walls that increases the contact area with the ground and helps transfer loads safely. |
| Footing beam | A foundation element that connects the footings and contributes to the uniform transfer of loads to the ground. |
| Floor slab | A floor slab is the horizontal surface that separates the storeys of a building, serving as the floor of the upper storey and the ceiling of the lower one. The slab works together with the beams and columns and forms part of the structure’s load-bearing system. |
| Rebar installation | The process of placing the steel reinforcement inside the formwork before reinforced concrete elements are poured. |
| Crushed stone aggregates | Crushed materials produced by breaking rock in quarries. They have an angular shape and are mainly used in concrete production, foundation bases and road construction. |
| Concrete | A mixture of cement, water and aggregates that develops high strength after hardening and is widely used in construction. Concrete is classified into strength classes in accordance with European standards (EN 206), such as C16/20, C20/25, C25/30 or C30/37. These classes indicate the characteristic compressive strength of the concrete. Classes such as C20/25 or C25/30 are commonly used in residential construction for foundations, slabs and beams, while higher classes may be used for more demanding structures. |
| Concrete pouring | The process of placing and compacting concrete inside the formwork to create the final structural element. |
| Glued laminated timber (glulam) | Glued laminated timber, or glulam, consists of multiple layers of timber bonded together to create an element with greater strength and stability. It is often used for large structural elements, such as beams or roof members, because it can span greater distances than conventional timber. |
| Cement screed | A thin layer of cement-based mortar applied to level floor surfaces before the final flooring materials are installed. |
| Column | A column is a vertical structural element that transfers the loads of beams and slabs to the foundation. It is a key part of the load-bearing structure and is designed to withstand the loads and seismic actions applied to the building. |
| Load-bearing structure | The load-bearing structure is the building’s main structural frame, which receives and transfers all loads to the foundation. It consists of the main structural elements, such as beams, columns, slabs or load-bearing walls, depending on the construction system. The load-bearing structure can be made from different materials. The most common are: • reinforced concrete • steel • timber In timber houses, the load-bearing structure is made of structural timber, and the loads are transferred through the timber elements to the foundation. The load-bearing structure is designed as part of the structural study so that the building has the required strength and seismic performance. |
| OSB (Oriented Strand Board) | OSB is an engineered wood product made from compressed wood strands bonded together with special resins. It is widely used in timber construction for sheathing walls, floors and roofs. This material provides high mechanical strength and contributes to the stability and rigidity of the structure. |
| Radier (raft foundation) | A radier, or raft foundation, is a type of foundation in which the building rests on a single reinforced concrete slab covering the entire footprint of the building. This slab acts as one structural element and distributes the building loads evenly to the ground. A radier foundation is commonly used in residential construction because it provides good load distribution, high structural rigidity and very good seismic performance. In many cases, the building’s main services, such as drainage and pipework, are incorporated before the concrete is poured. |
| TERMS | EXPLANATION |
|---|---|
| Atrium | An internal open-air space within a building, usually open to the sky. It brings natural light and ventilation into the interior. |
| Opening (for a door or window frame) | An opening in a wall where a window or door is installed. |
| Architectural study | The study that defines the form, layout and function of a building. It includes floor plans, elevations, sections and the overall architectural appearance of the structure. |
| Architectural projection | A section of the building that projects beyond the main volume, such as boxes or cantilevered elements. It adds depth and character to the design. |
| Architectural composition | The way in which spaces, elevations and morphological elements are organised to create a complete architectural result. |
| Veranda (filled or raised) | An outdoor area that forms an extension of the house. It may be at the same level as the house or raised. |
| Bioclimatic design | A design approach that makes use of the sun, air and surrounding environment to save energy. It reduces heating and cooling requirements. |
| Roof eaves | The part of the roof that extends beyond the external wall of the building. It protects the façade from rain and contributes to shading the building. |
| Flat roof (roof terrace) | A horizontal roof with no slope. It may be used as an outdoor area or accommodate installations such as photovoltaic panels or mechanical equipment. |
| Accessible flat roof | An accessible flat roof is a level roof that can be used as a functional outdoor space. The final surface is usually finished with ceramic tiles installed on adjustable supports (pedestals), allowing the area to be used as a terrace or seating space. |
| Non-accessible flat roof | A non-accessible flat roof is a level roof whose final surface consists of the waterproofing layer. Access is allowed only occasionally for maintenance work, such as servicing the solar water heater. |
| Balcony | A projecting structure extending from the façade of a building and used as an outdoor space. |
| Bay window | An enclosed projecting space that extends outwards from the façade of a building. |
| Internal layout | The arrangement of spaces within a building and their functional organisation. |
| Floor plan | An architectural drawing showing the layout of the spaces on a floor, as if the building were viewed from above. |
| Drawing scale | The ratio used to represent a building in a drawing in relation to its actual dimensions, for example 1:50 or 1:100. |
| Sloped ceiling | An internal ceiling with a slope that follows the shape of the roof. It creates greater height, a stronger sense of space and a more distinctive architectural result. |
| Flat ceiling | A horizontal internal ceiling, regardless of the type of roof. It creates a clean and modern interior. |
| High ceiling | A ceiling with a greater clear height than usual. It makes the space feel more comfortable, brighter and more impressive. |
| Building elevation | The external surface of a building as viewed from each side, including the front, rear and side elevations. |
| Mezzanine | An intermediate level within a space with a high ceiling. It makes use of the vertical volume of the space. |
| Pergola | A pergola is a lightweight shading structure, usually consisting of beams or slats without full coverage. It is used to provide shade on verandas, in gardens or in other outdoor areas. According to the New Building Regulation (NOK), a pergola is considered a shading structure and is permitted in specific areas of a plot or residence without counting towards the building area, provided that the relevant requirements are met. |
| Façade | The main elevation of a building, usually the side facing the street or the principal outdoor area. |
| Attic | A space beneath the roof, usually with limited height. It may be used as a bedroom or storage area. |
| Canopy | A canopy is a structure that covers an outdoor area and provides protection from the sun and rain. Unlike a pergola, it usually has full coverage, such as roof tiles, panels, polycarbonate sheets or other materials. Under the New Building Regulation (NOK), a canopy is considered an auxiliary structure and is permitted under specific conditions regarding its dimensions and location. |
| Roof | The uppermost structure of a building, which protects it from weather conditions. It may be flat or pitched and may be covered with various materials, such as roof tiles or metal sheets. |
| Gable roof | A roof with two sloping surfaces that meet at a ridge. A classic and timeless form. |
| Exposed roof structure | A roof whose structural elements remain visible from the interior, without a suspended ceiling. In gable roofs, the main large engineered-timber beams are usually visible, while in hip, half-hip or multi-level roofs, the roof trusses are generally exposed. |
| Mono-pitched roof | A roof with a single slope. It creates a modern and clean result. |
| Butterfly roof | A roof with opposing slopes that form a “V” shape. An impressive and distinctive architectural feature. |
| Multi-level pitched roof | A roof with more than one slope and different levels, combining multiple volumes and geometries. It gives the building a more complex and distinctive form. |
| Hip roof | A roof with four sloping sides. It has a more enclosed form compared with a gable roof. |
| Section | An architectural drawing showing a vertical cut through the building so that the heights of the spaces and the construction elements can be seen. |
| Clerestory window | A small opening or window usually positioned high on a wall or in the roof to provide light and ventilation. |
| Lightwell | An empty vertical space within a building that allows natural light and ventilation to reach internal spaces. |
| TERMS | EXPLANATION |
|---|---|
| Lump sum | An agreed total price for the project. |
| Project budget | A detailed estimate of the project’s total cost. |
| Withholding tax | An amount withheld for tax purposes. |
| IKA construction insurance contributions | The social security contributions paid for workers employed in construction works. In conventional construction, most of the work is carried out on site, and the insurance contributions are usually calculated based on the building’s surface area, covering the full range of construction works. In prefabricated homes, a large part of the construction takes place in factory facilities. The workers employed there are insured by the company as normal, and their social security contributions are included in the production cost of the building. For work carried out on site, a special calculation method provided for by law applies, known as Table 3. The insurance contributions arising from the project mainly concern so-called non-sheltered construction trades, such as concrete, plastering, tiling and painting works. For this reason, the insurance contributions calculated for the construction site are usually significantly lower than in conventional construction, as a large part of the work and the workers’ insurance coverage has already been completed at the factory. |
| Building permit fees | The issuance of a building permit includes two main cost categories: the cost of the studies (that is, the engineers’ fees for preparing the required studies) and the permit fees. Building permit fees are amounts paid to public or municipal authorities during the project licensing process and do not constitute engineers’ fees. These fees usually include: fees payable through the e-Permits system contributory fees in favour of the Technical Chamber of Greece (TEE) Building Control inspection costs advance payment of construction-sector IKA insurance contributions contributions to the Green Fund in certain cases (e.g. construction outside the town plan) the cost of participation in the excavation and demolition waste recycling system (AEKK) The exact amounts depend on the size of the project, the building’s surface area and the legislation in force. |
| TERMS | EXPLANATION |
|---|---|
| Thermal insulation | Thermal insulation is the combination of materials and construction solutions that limit heat transfer between the interior and exterior of a building. Proper thermal insulation helps maintain a stable temperature inside the home and significantly reduces heating and cooling requirements. Thermal insulation materials are usually installed in external walls, roofs and floors. |
| Thermal transmittance coefficient (U-value) | The thermal transmittance coefficient expresses the amount of heat that passes through a building element, such as a wall, roof, floor or window. It is measured in W/m²K and indicates how easily heat is transferred through a material or construction assembly. The lower the U-value, the better the thermal insulation performance of the element. |
| Thermal resistance (R-value) | Thermal resistance expresses the ability of a material or building element to resist heat transfer. It is measured in m²K/W and is the inverse of thermal transmittance. The higher the thermal resistance, the better the thermal insulation performance of the element. |
| Thermal insulation material | Thermal insulation materials are materials used in construction to reduce heat transfer through a building’s structural elements. Various insulation materials are used in residential buildings, including rock wool, expanded or extruded polystyrene and other modern insulation materials. |
| External thermal insulation system | An external thermal insulation system is applied to the exterior walls of a building. It usually consists of insulation boards fixed to the wall, special mortars, reinforcing fibreglass mesh and a final render coat. External thermal insulation significantly reduces heat loss and helps improve the building’s energy performance. |
| Rock wool | Rock wool is a thermal insulation material produced from natural rocks that are melted and spun into fibres. It is widely used in walls, roofs and floors because it provides good thermal insulation, very good sound insulation and high fire resistance. It is also a vapour-permeable material that allows building elements to breathe. |
| Expanded polystyrene (EPS) | Expanded polystyrene is a lightweight thermal insulation material made from polystyrene beads that expand when heated. It is widely used in external thermal insulation systems and other insulation applications because of its low weight and good thermal insulation properties. In Greece, it is commonly known by the trade name Styrofoam, a name popularised by a company that widely distributed the material in previous decades. |
| Extruded polystyrene (XPS) | Extruded polystyrene is a thermal insulation material with a closed-cell structure that gives it high resistance to moisture and mechanical stress. It is often used in areas of a building where increased strength is required, such as floors, foundations or inverted flat roofs. In everyday use in Greece, it is often referred to as blue polystyrene or by the trade name Dow, after a company that widely introduced the product to the market. |
| Thermal bridge | A thermal bridge is an area of a building where the insulation is interrupted or reduced, allowing more heat to pass through than in the surrounding building elements. Thermal bridges usually occur at junctions between building elements, such as wall corners, wall-to-slab connections or around window and door frames. Proper insulation design and construction help minimise thermal bridges and improve the building’s energy performance. |
| Wall vapour permeability | Wall vapour permeability is the ability of a construction assembly to allow water vapour to pass gradually through its building materials. Proper vapour permeability helps prevent moisture from accumulating inside the wall and contributes to maintaining a healthy indoor environment. For this reason, the selection of materials and the correct arrangement of the wall layers are particularly important. |
| Passive building | A passive building is a building with very high energy performance, designed to require exceptionally little energy for heating and cooling. This is achieved through very effective thermal insulation, the reduction of thermal bridges, an airtight building envelope and the use of ventilation systems with heat recovery. The aim of passive design is to achieve a high level of thermal comfort with minimal energy consumption. |
| Passive building study | A passive building study is a specialised energy study that assesses whether a building meets passive design criteria. It evaluates parameters such as thermal insulation, airtightness, thermal bridges, windows and doors, and the building’s ventilation system. Based on the results of the study, the building may be certified as meeting passive building standards. |
| Building airtightness | Building airtightness expresses the extent to which the building envelope prevents uncontrolled air movement from outside to inside and vice versa. Good airtightness helps reduce heat loss and improve the building’s energy performance. At the same time, it allows better control of ventilation and indoor air quality. In high-energy-performance buildings, airtightness is a fundamental design element. |
| Mechanical ventilation | Mechanical ventilation is a ventilation system that uses fans and ducts to renew the air inside a building. Unlike natural ventilation through windows, mechanical ventilation allows controlled ventilation of the rooms and a continuous supply of fresh air to the interior of the home. It is often used in high-energy-performance buildings where airtightness is increased. |
| Heat recovery ventilation (HRV) | Heat recovery is a technology used in mechanical ventilation systems. In these systems, warm air extracted from the interior of the building transfers part of its heat to the fresh air entering from outside. This renews the air inside the building without significant heat loss, improving energy performance and indoor comfort. |
| TERMS | EXPLANATION |
|---|---|
| Heat pump | A heating and cooling system that uses energy from the surrounding environment (air or ground), transferring heat with very high efficiency (COP of up to 3–5). In simple terms, for every 1 kW of electricity it consumes, it can deliver up to 4–5 kW of heat. It is currently one of the most modern and efficient solutions for homes, especially when combined with underfloor heating or fan coil units. |
| Solar water heater (dual / triple energy) | A hot-water production system that uses solar energy and can be combined with backup energy sources. 🔹 Dual energy: Solar energy + electric heating element (the standard solution for most homes) 🔹 Triple energy: Solar energy + electric heating element + connection to the heating system (e.g. a heat pump or boiler / radiator system) |
| Boiler | A hot-water storage tank connected to a heating system. |
| Buffer tank | A tank that stores thermal energy to ensure more stable operation of the heating system. |
| Room thermostat | A device that controls the operation of the heating or cooling system based on the room temperature. |
| COP | The coefficient of performance of a heat pump under specific operating conditions. |
| SCOP | The average seasonal performance of a heat pump throughout the heating season. |
| Underfloor heating | A heating system with pipes installed within the floor that distribute heat throughout the space. |
| Fan coil | A heating and cooling unit that uses water and a fan to distribute air throughout the space. |
| Circulation pump | A pump that circulates water through the heating system. It ensures the proper distribution of heat. |
| Expansion vessel | A vessel that absorbs pressure fluctuations within the heating system. It is essential for the safe operation of the installation. |
| Main connection line – Power supply | The connection between the building and the electricity grid. It is essential for the operation of all electrical systems. |
| HEDNO pillar | An external electrical cabinet where the property’s power supply terminates. It is usually installed at the boundary of the plot. |
| TERMS | EXPLANATION |
|---|---|
| Wastewater drainage | A piping system that removes used water from the residence. |
| Stormwater drainage | A system for collecting and removing rainwater. |
| Drainage inspection chamber | An underground access point to the drainage network for inspection and cleaning. |
| Floor drain | A drainage fitting that collects water from the floor and prevents odours from flowing back into the room. |
| Drainage ventilation | A piping system that allows air to circulate within the drainage network. |
| Cesspit | An underground tank used to collect wastewater in areas without a sewer network. |
| Biological wastewater treatment | A system that treats wastewater through natural and biological processes. |
| Greywater | Lightly used water from showers, washbasins and washing machines. |
| Separation of greywater and blackwater | The separation of wastewater so that greywater can be treated and reused. Provision for this separation must be made at the design stage, as it requires a separate piping network. |
| Drainage non-return valve | Prevents wastewater from flowing back. |
| Septic tank | A tank used to collect wastewater without treatment. It is selected for simple installations in areas without a sewer network. |
| Soakaway pit | A tank that allows liquids to be gradually absorbed into the ground. It is usually used in combination with a septic tank. |
| Single-lever mixer tap | A tap that mixes hot and cold water using a single control. It provides easy temperature adjustment and comfortable use. |
| Concealed mixer tap | A tap whose mechanism is installed inside the wall, with only the controls visible externally. It creates a minimal and clean aesthetic result. |
| Floor-mounted mixer tap | A tap installed on the floor, usually next to a freestanding bathtub. It forms a strong design feature. |
| Deck-mounted mixer tap | A tap installed on a washbasin or countertop. It is the most common choice for bathrooms and kitchens. |
| Wall-mounted mixer tap | A tap installed on the wall above the washbasin. It keeps the countertop clear and creates a cleaner visual result. |
| Concealed cistern | A cistern installed inside the wall and hidden from view. It is usually combined with a wall-hung toilet. |
| Exposed cistern | A visible cistern installed behind the toilet. A simple and cost-effective solution. |
| Wall-hung toilet | A toilet fixed to the wall without touching the floor. It offers a modern appearance and makes cleaning easier. |
| Floor-standing toilet | A traditional toilet installed directly on the floor. Simple, reliable and easy to install. |
| Shower column | A shower system with a vertical column that includes an overhead shower, a hand shower and controls. It provides a complete showering experience. |
| Main connection line – Water supply | The connection between the building and the water supply network. It is essential for the operation of all plumbing installations. |