Plans
Plans are documents that contain construction drawings that serve to provide a visual representation of the building project. They contain information such as the sizes and dimensions of construction elements, installation details of materials, and layout of components (e.g. building position, piping).
Specifications
As opposed to plans, specifications are documents that contain a textual description of the drawings found in the construction plans. It further explains the drawings found in the construction plans and presents additional information that cannot be expressed clearly through drawings.
Amendments
As a building and construction project progresses, changes or revisions will most probably occur. Some examples include clients changing the dimensions of spaces based on their preference or contractors changing material specifications due to the unavailability of some construction supplies.
Technology used in developing plans and drawings
In identifying types of plans, two related concepts include computer-aided design (CAD) drawings and building information modelling (BIM). Both CAD and BIM are technologies used in the construction industry to create and manage construction drawings.
Types of plans
In a building project, different types of plans serve different purposes and contain specific technical details regarding the different areas of construction. These can include concept drawings or sketches, architectural plans, structural plans, civil plans, mechanical plans, electrical plans, plumbing and draining plans and utilities and services plans and specifications.
Drawing conventions
Drawing conventions are a set of standards, commonly used techniques used in construction plans. These drawing conventions include the following: datum and reduced levels, title block, scale, dimensions and abbreviations.
Key features of the plans
| Type of plan | Key features |
|---|---|
| Concept drawing/sketches |
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| Architectural |
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| Structural |
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| Civil | (Same as architectural plans and structural plans) |
| Mechanical |
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| Electrical |
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| Plumbing and draining |
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| Utilities and services |
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- To know more about the General Requirements and Performance Requirements, read the National Construction Code, NCC (2019) Volumes 1, 2, and 3 are available on ABCB’s website, upon free registration.
- This document is from Construct Law Group. It covers more discussion about Prime Cost (PC) and Provisional Sum (PS) items
- This document contains a sample specification document for a proposed single storey residence.
- Your Home: Free Home Designs is licensed by © Commonwealth of Australia 2020. Design For Place is licensed under CC BY 4.0, and provided free of charge at www.yourhome.gov.au. Sample plans and drawings can be accessed here regarding Banksia House (Sydney).
- Additional sample plans used throughout the modules can be accessed here: residential floor plan, floor plan with dimensions, site plan, slab plan, construction notes, footing plan and details, roof framing plan and details.
- AS 1100.101-1992 Technical drawing - General principles can be purchased through Standards Australia or SAI Global. The hyperlink shows a sample of the document.
- AS ISO 128.20-2005 – Technical drawings - General principles of presentation, Part 20: Basic conventions for lines can be purchased through Standards Australia or SAI Global.
- AS 1684.2-2021 - Residential timber-framed construction, Part 2: Non-cyclonic areas can be purchased through Standards Australia or SAI Global. The hyperlink shows a sample of the document.
Standards Australia, in partnership with the Australian Building Codes Board (ABCB), produced an online dictionary of terms for the building and plumbing industry. The dictionary can be accessed here.
Below you can see a list of terms explained that were frequently used in this module:
| Term | Definition |
|---|---|
| Architectural plans | Architectural plans are drawings used to acquire information about the architectural aspects of a building and how architectural elements are integrated into the building. |
| BIM | Building Information Modelling that is a 3D model-based process that utilises tools and technologies that enable the creation and management of digital representations of physical and functional characteristics of structures, buildings and places. |
| CAD | Computer-aided design drawings. These can be created and modified with the use of computer software. These drawings may be two-dimensional (2D), or three-dimensional (3D) illustrations or models created and used by engineers, architects, and construction managers to create precise drawings of the building and its components. |
| Civil plans | Civil plans are drawings that are typically provided by Civil Engineers and show an overview of all the construction site elements including storm water management, road-, and other paved areas. They also show how these integrate into each other during the construction phase. |
| Concept drawings/ sketches | Concept drawings and sketches are simple 3D drawings that are drawn free-hand or with sketching software. In other words, creating concept drawing and sketches do not require the use of advanced drawing software such as computer-aided design (CAD). |
| Datum | Datum is a reference point on or near the block upon which all site elevations are measured from. |
| Electrical plans | Electrical plans are drawings used to acquire information about building elements related to electrical systems or circuits, such as power, lighting, and communication. |
| Isometric drawings | They are 3D drawings on a 2D surface where the same scale is used for all axes. Additionally, these drawings are set out using 30-degree angles. Isometric drawings are used for the purpose of viewing a 3D image with the corresponding scaled dimensions since these drawings represent a non-distorted version of an object. |
| Manhole | It is an inspection chamber or opening fitted with a hinged or removable cover, which permits entry of a person under a floor, above a ceiling, or to an inspection chamber, pipeline or closed vessel to facilitate inspecting, testing, or the clearance of obstructions |
| Mechanical plans | Mechanical plans are drawings that contain the plans and specifications related to mechanical equipment and processes, such as heating, cooling, ventilation, and transportation. Examples of mechanical equipment include heating, ventilation and air-conditioning systems (HVAC), lifts, escalators, and ducting. |
| Oblique drawings | Oblique drawings are the 2D projection of 3D drawings that represent an object accurately by showing the true shape and form of the object based on the observer's point of view. This is typically used to directly look at certain features of an object based on the desired view of the viewer. |
| Orthographic drawings | Orthographic drawings are drawings wherein 3D images are presented in 2D, in which three views are produced (e.g. top view, front view, and side view). |
| Path | Any paving works included in the contract |
| Perspective drawings | Perspective drawings are 3D drawings that show an approximate representation of an object as the eye perceives it. These drawings are typically used to give a realistic representation of the building. |
| Plumbing and draining plans | Plumbing and draining plans, also known as plumbing and drainage plans, are drawings that provide visual representations of elements related to plumbing systems. These plans can be used as a guide in the installation of water supply and drainage components such as pipes, fixtures, valves, sanitaryware, etc. |
| Prime cost (PC) | Amount included in the contract documents to cover the purchase by the contractor of a specified item, such as a particular fixture or fitting, but excluding any associated labour. For example: tiles, taps, doors or bathroom fittings. In New Zealand, a prime cost item is called ‘net sum’. |
| Provisional sum (PS) | Amount of money included in the contract documents to cover works proposed as part of the contract but for which there is insufficient detail at the time of calling tenders. Typically, builders will include a PS for sitework costs. For example: excavator hire, underground rock removal, earthworks on a site where there is uncertainty about soil conditions. |
| Scale | Scale refers to the ratio that dictates the size of scale drawings, which are drawings used for accurately illustrating real-life building components or items at fixed, reduced, and enlarged sizes. |
| Utilities and services plans | Utilities and services plans are drawings that contain information about construction site utilities and services. |
