We know that the world of Architecture is full of some confusing jargon. So, we wrote this jargon buster to help clarify a few of the terms your architect may use. We hope that you find it helpful! Please do let us know if there’s anything you think should be added. Email [email protected].

Air admittance valve (AAV): Commonly called Durgo valves, air admittance valves are designed to decrease the number of pipes that need to penetrate the roof and walls of a property. They reduce the number of parts required to ventilate soil and waste removal systems and do not compromise the performance or either. These valves essentially let trap seals within the system work correctly and effectively by creating negative air pressure in the system.

Articulation: creating interest to a large or uninteresting surface by adding windows, alternative materials, features, etc.

Approved Documents: a set of documents providing guidance on how to meet the requirements of the Building Regulations

Boundary: An imaginary line that marks the limits of two adjacent pieces of real property. The line is generally, but not necessarily, marked or indicated on the surface of the land by a wall, fence, ditch or another object.

Building Envelope: the walls, floors, roofs, windows, and doors

Area of Outstanding Natural Beauty (AONB): An area with statutory national landscape designation, the primary purpose of which is to conserve and enhance natural beauty. Together with National Parks, AONB represents the nation’s finest landscapes. AONB are designated by the Countryside Agency.

Axonometric projection: A three-dimensional drawing to combine the plan and elevations. The accurate plan is drawn at a convenient angle and verticals from suitable points create the elevations. All horizontal and vertical dimensions are to scale, but diagonals and curves on a vertical plane are distorted. The result is similar to a perspective.

Best Value (Value for Money): The value that is represented by considering quality and lifetime costs, rather than construction costs alone. Central and local government clients are charged with obtaining best value for their construction projects, as for all other aspects of government, rather than seeking lowest price.

Bill of quantities: A list of the costs – usually a contract document – which is calculated by a quantity surveyor (see below) from the architect’s drawings and specifications using a ‘standard method of measurement’. If planned works are changed they are re-measured to calculate the change in cost.

Building Information Modeling (BIM) software: Building Information Modeling (BIM) is an intelligent 3D model-based process that gives architecture, engineering, and construction (AEC) professionals the insight and tools to more efficiently plan, design, construct, and manage buildings and infrastructure.

Brief: Description of what a client wants to include in the project and how the finished building is to perform. Different terms are used in different guidance documents. The brief develops in complexity from a simple statement of need and/or a vision, through an outline or strategic brief, to a detailed, quantified brief for design. See Detailed design brief, Outline brief, Strategic brief, Statement of need/requirements, Project brief, Vision.

Building inspector: The person responsible for inspecting building projects on site to ensure that all building regulations are being met. Normally an officer in the local authority.

Building Regulations: statutory standards for design and construction of buildings which ensure minimum standards for health, safety, welfare, energy efficiency, sustainability, etc.

Building Surveyor: A surveyor trained in building construction, law and sometimes costing. Often leads the design team for alterations to an existing building.

Cable Capping: Thin metal or plastic channelling sometimes used to contain electrical cables when fixed to a wall. This capping makes it easy to run multiple cables together.

CAD [Computer-aided Design]: drawings and design produced on a computer rather than by hand

CDM [Construction (Design and Management) Regulations]: a set of regulations for managing the health, safety and welfare of construction projects

Change of Use: A change in the way that land or buildings are used (see Use Classes Order). Planning permission is usually necessary in order to change from one ‘use class’ to another.

Character: A term relating to Conservation Areas or Listed Buildings, but also to the appearance of any rural or urban location in terms of its landscape or the layout of streets and open spaces, often giving places their own distinct identity.

Cladding: Where the mortar used to join bricks or stone of a building begins to degrade, repointing renews the exposed mortar. This reseals the building from the elements. The remaining old mortar is usually chipped away first.

Conservation Area: Areas of special architectural or historic interest, the character or appearance of which it is desirable to preserve or enhance.

Context: the features, both natural and manmade, surrounding a building or site

Contingency: Provision of time or money for unforeseen problems arising during the construction project. The money set aside should relate to the degree of risk, and be part of a formal risk management approach. Risk and
uncertainty and can be reduced as the project proceeds.

Density: In the case of residential development, a measurement of either the number of habitable rooms per hectare or the number of dwellings per hectare.

DPC [Damp Proof Course]: a ribbon of plastic that stop moisture moving from one part of a building to another.

DPM [Damp Proof Membrane]: the sheet of plastic that separates the building from the ground and prevents damp getting in

Detail: The technical construction specifications you will see on your plans.

Economic impact: The effect a project has on the local economy. An increasingly important factor in achieving a successful project. Specialist input should be sought when a business case requires the prediction of economic impact and regeneration benefits.

Elevations: drawings showing what each external face of a building looks like

Energy efficiency: The quest to reduce the amount of fuel required to heat, cool, light and run a building, compared to standard consumption.

Façade: exterior wall of a building, which is usually, but not always, the front

Fascia: Part of the face or elevation of a building, where the shop or occupier’s name is usually displayed.

Fenestration: openings in the walls and roof, including windows, doors, roof lights, etc.

Feasibility study: A review carried out objectively and early in the process to check whether a set of proposals is likely to fulfil the organisation’s objectives and whether the chosen site is suitable for the intended building. It is not a fundraising document.

FFL [Finished Floor Level]: the top of the floor that you walk on

Flood Risk Assessment: An assessment of the likelihood of flooding in a particular area so that development needs and mitigation measures can be carefully considered.

Gable: A peaked, usually triangular, portion of wall at the end of a double pitched roof. The terms ‘gable wall’ and ‘gable end’ mean the entire external wall.

Habitable rooms: Any room used or intended to be used for sleeping, cooking, living or eating purposes. Enclosed spaces such as bath or toilet facilities, service rooms, corridors, laundries, hallways, utility rooms or similar spaces are excluded from this definition.

Handover: The moment at which responsibility for the completed building, including insurance and management, is passed from the contractor to the client. A full check is needed to ensure that everything promised under the contract has been fulfilled.

Herringbone pattern: The pattern of bricks, wood or tiles where they are arranged like the bones of a fish. See the image below of herringbone wood flooring at Beamish Museum.

Infill Plot: Infill plots are in an urban or village setting and are a gap in the street scene.

Insulation: materials used to stop heat escaping (thermal insulation) or the transfer of noise (acoustic insulation)

Jettying: In timber-framed homes, a jetty is a projection of an upper storey beyond the storey below to maximise the available space in buildings without increasing the footprint. Using a cantilever, the system is made by the beams and joists of the lower storey oversailing to support the wall above.

Latent defects: These are building defects that appear after completion. They are covered by Limitation Acts, which state a time limit after which claims cannot be brought for errors in the design and construction. If, during this period, the client can prove that the design or construction team is responsible for any defect, they will normally be liable for losses suffered by the client as a result.

Legibility: The ease of understanding a building and knowing how to find one’s way around and use it.

Lintel: a beam that is used over a door or a window to create the opening

Massing: the shape, form and size of a building

Mixed use: Provision of a mix of complementary uses, such as residential, community and leisure uses, on a site or within a particular area.

Orientation: the positioning of a building or parts (Eg. windows) in relation to the sun, wind, etc.

Original house: The term \’original house\’ means the house as it was first built or as it stood on 1 July 1948 (if it was built before that date). Although you may not have built an extension to the house, a previous owner may have done so.

OS Plan [Ordnance Survey Plan]: a plan produce by the Ordnance Survey mapping company which shows buildings in relation to their surroundings – roads, paths, other buildings, etc.

Outline planning permission/consent: Outline permission can be sought for a building before detailed designs have been proposed, based on an outline scheme. Normally full planning permission is sought after discussion to determine the likely acceptability of the project. See Planning permission below.

Party Wall: a shared wall between two adjoining buildings

PD [Permitted Development]: what you can build without planning permission

Planning permission: Permission that must be obtained from the local authority before construction starts on most projects. It controls the proposed use, how much of the site is covered, the size of the building, site access, external landscape and parking and conformity with existing local plans. If permission is not granted, an appeal may be heard by a public enquiry and determined by a planning inspector. The Secretary of State for the Environment makes the final decision.

Quantity surveyor (QS): A specialist in all aspects of the costs of construction, providing information on the likely cost of a project at every stage including cash flow. The QS can also advise on the form of contract, procurement routes, suitable contractors, inflationary allowances and the need to make contingencies in the cost model.

Rainwater Downpipe: A rainwater downpipe is a pipe that is used to direct rainwater away from a building, typically from roof guttering to a drainage system. It is sometimes also referred to as a downspout, drainspout, roof drain pipe or leader.

Render: The coating applied to the exterior of a home to protect the building from weathering. Render can be simply decorative.

Revit: Autodesk Revit is Building Information Modeling (BIM) software for Microsoft Windows, which allows the user to design with parametric modelling and drafting elements. We use this state of the art software to design and develop your project. It enables us to show you 3D models of how your project will look.

RWP [Rain Water Pipe]: the pipes that take rain water from the roof to the sewer

RSJ [Rolled Steel Joist]: a beam, usually ‘I’ shaped

Scale: the size of a building in relationship to another building or its surroundings

Section: drawing based on a vertical cut through the building

Setback: distance a building is set back from a street or from an adjacent part of the same building

Site Plan: A plan of your whole site, including surrounding land.

Snagging: the process of identifying and fixing defects prior to project completion. The responsibility for remedying these normally lies primarily with the contractor. The project timetable should always allow time for snagging before move-in. However, some items, such as air handling systems, can only be fully tested after running through all seasons of the year.

Soil vent pipe: this commonly runs vertically from the underground drainage system to the top of a property, just above roof gutter level. It is also known as a soil stack pipe, a drain waste vent or a ventilated discharge pipe.

Statutory Applications: applications required by law in relation to building projects. Eg. Planning and Building Regulations

Structural calculations: A structural calculations report provides a full outline of design and build work to be carried out. It is minutely detailed and will include such information on how the foundations are to be dug, materials required, structural works, supporting walls, measurements, beams, joists, rafters, load bearings and concrete reinforcement or steel connection calculations. The report will be created by a qualified structural engineer. Where required, this report will ensure that our design meets to correct safety standards.

Structural engineer: Engineer specialising in the design of building structures. Decisions about the type of structure are integral to the design and should be taken with the architect. The engineer is responsible for ensuring that the structure has the appropriate strength and flexibility.

Structural Opening: opening in the wall of a building, often for a door or window

Surveyor: a surveyor measures and maps out various aspects of land and buildings, for example in relation to dimensions, costs and construction.

Sustainable materials: resources that will not be exhausted. For example, timber from renewable forests is sustainable, while that from slow-growing tropical hardwoods is not. Sustainability is a concept that good design is expected to incorporate, reducing waste, promoting whole life value and a healthy environment

Tender process: this is the process of inviting organisations to submit a proposal, with costs, to carry out a piece of work. It covers the preliminary invitation to tender, formal invitation to tender and the actual form of tender.

U-Value: a measurement of how good walls, roofs, walls and windows are at stopping heat escaping from a building

Value management/Value engineering: A formalised approach to managing a project through its whole life that seeks best value for money. Multi-disciplinary workshops can be organised to determine whether better value solutions are possible within the constraints of the brief and the project.

Variation: a statement of the costs associated with changes to the contracted works.

Vernacular: design that is based on identifiable local materials, styles and traditions

Weatherboarding: A type of cladding which is usually made from timber – sometimes UPVC – which is laid with an overlap to prevent damp.

Whole life costs: The full cost of all the parts that go to make up a building, including initial capital costs, replacement costs, maintenance and repair costs. Sometimes referred to as life cycle costs.

Whole life value: Value of an asset when its whole life costs are considered. Sustainability is an important aspect of whole life value.

The Team @ Acre Design hope that you have found this architect’s jargon buster useful! Please check out or latest projects if you’d like to see what we’re made of. Our Instagram, Pinterest and Facebook pages are all brimming with extension, loft conversion and self-build inspiration too!