Patio & Shed Glossary WA
Plain-English definitions of WA patio, shed, engineering and approval terms
Buying a patio or shed in Western Australia comes with a lot of jargon — wind regions, terrain categories, footings, Z purlins, building permits and more. This glossary explains the terms in plain English so you can read quotes, compare kits and ask the right questions with confidence.
Quick Answer
This glossary defines the key patio, shed, engineering, materials and approval terms used across Western Australia. Understanding them helps you compare DIY kits accurately, understand what a quote includes and read the stated design basis in project documents. Browse by category below, or jump straight to a term.
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Select any term to jump straight to its definition.
Engineering
General structural terms used on patio and shed drawings and specifications.
Wind Region
A geographic classification used as one input when establishing wind design actions.
A wind region is a geographic classification used when wind design actions are established for a site. Australia uses regions A, B, C and D, and Western Australia includes more than one region. Wind region is considered with other site and building information; it does not by itself specify member, footing, bracing or fixing details.
Terrain Category
A classification of the surrounding surface roughness used when assessing wind exposure.
Terrain category describes the general surface roughness around a site, such as open ground or established suburban development. It is one of several inputs used to assess wind exposure. The applicable classification and design consequences are project-specific.
Engineer Certification
Documentation from an engineer about a particular design and its stated design basis.
Engineer certification is documentation from an engineer about a particular design and the assumptions, criteria or standards stated in that documentation. Its scope is project-specific: certification does not by itself confirm planning or building approval, site suitability, or that later changes and installation work are covered. The relevant permit authority or building professional can explain what documents are required for a particular project.
Footing
A below-ground or ground-level part that transfers loads from a structure into the supporting ground.
A footing is the part at the base of a structure that spreads or transfers loads into the ground. Patio and shed footings are often concrete, but their form, size and depth are project-specific matters that can depend on the design, site and ground conditions.
Span
The distance between two supports, such as posts, without another post in the middle.
A span is the distance a member or surface extends between supports. It is one input used in structural design; suitable member sizes and support arrangements depend on the complete project design rather than span alone.
Structural Member
An individual part of a structure that carries or transfers load.
A structural member is one part of a load-carrying system, such as a column, beam, rafter, purlin or girt. Each member has a particular location and role within the overall design.
Column
A generally upright structural member that carries loads down towards its support.
A column is a vertical or near-vertical member in the main frame. In everyday kit language it may also be called a post, although drawings and specifications should be checked for the term used on a particular project.
Beam
A structural member that spans between supports and carries loads along its length.
A beam is commonly horizontal or sloping and transfers loads to columns, posts, walls or other supports. Its exact role is shown by the project drawings.
Rafter
A sloping roof member that runs in the direction of the roof fall.
A rafter forms part of roof framing and supports roof components above it. Depending on the building system, rafters may be part of the main frame or may be supported by other members.
Purlin
A roof-framing member that supports roof cladding and transfers load to the main framing.
Purlins usually run across rafters or main frames and provide intermediate support for roof cladding. They can be made in different shapes and materials; a Z purlin is one common cold-formed steel section.
Girt
A wall-framing member that supports wall cladding between columns or main frames.
Girts generally run horizontally along a wall and transfer loads from wall cladding to the main framing. Their arrangement is defined by the building design.
Portal Frame
A main structural frame made from connected columns and rafters.
A portal frame is a set of columns and rafters connected to act together as a main frame, often creating a clear internal area. A shed can use a series of portal frames, with secondary members supporting the roof and wall cladding between them.
Connection
The place and method by which two or more building parts are joined.
A connection joins members or components so forces can pass between them. Connections may use bolts, screws, welds, brackets or other details, but the required detail is specific to the project drawings and supplied instructions.
Opening
A planned gap in a wall or roof, such as a door, window or access opening.
An opening interrupts the surrounding cladding and may also affect framing layout. Its location and dimensions should be read from the project drawings; changing an opening can change the design basis.
Approvals
The permits and approvals you may need before building — these vary by local government area.
Building Permit
An approval issued by the relevant permit authority where the current rules require one.
Whether a patio or shed needs a building permit depends on the project, property and current requirements applied by the relevant permit authority. Do not assume that a project is exempt or that a particular document set applies; confirm the current pathway for the specific proposal before building.
Planning Approval
A separate approval that looks at where your patio or shed will be built on your property.
Planning approval is different from a building permit. Planning approval looks at where your patio or shed will be built on your property, and can include things like how close it is to boundaries, how tall it is and whether there are special rules in your area. Some projects need planning approval, some need a building permit, some need both and some may not need either. The rules can be different depending on where you live, so it is best to check with your local council before you build.
Certified Building Permit Application
A BA1 building permit application lodged with a Certificate of Design Compliance.
A certified building permit application (BA1) is lodged with a Certificate of Design Compliance (BA3) signed by a registered building surveyor. The permit authority still assesses the application; certification does not guarantee that a permit will be granted.
Uncertified Building Permit Application
A BA2 pathway for eligible Class 1a and Class 10 building permit applications.
An uncertified building permit application (BA2) is available only for eligible Class 1a and Class 10 projects. The permit authority carries out assessment and certification in that pathway; eligibility and approval must be confirmed for the project.
Certificate of Design Compliance
A BA3 certificate from a registered building surveyor used with a certified application.
A Certificate of Design Compliance (BA3) is issued by a registered building surveyor for a certified building permit application. Its scope and suitability are project-specific, and it is not itself a building permit.
Permit Authority
The authority with the statutory role of receiving and deciding a building permit application.
A permit authority receives and assesses building permit applications and makes the permit decision under its statutory role. Confirm the relevant authority and its current requirements for the particular property and project.
Local Government
The local public authority for an area, with roles that can include planning and permit functions.
A local government is the public authority for a defined area. It may have planning and permit-related roles, but the applicable process and requirements depend on the project and current rules.
Development Approval
A planning decision about a proposed development, separate from a building permit.
Development approval is a planning decision that can address matters such as land use, siting, setbacks, height and applicable planning controls. It is separate from a building permit, and one approval does not automatically replace the other.
Owner Builder
A person who manages their own building project instead of hiring a builder to do everything.
An owner-builder manages building work on their own property rather than engaging one builder for the whole project. The legal meaning, eligibility and approval requirements depend on the work and jurisdiction, so the relevant authority should be consulted. Buying a DIY kit does not by itself establish owner-builder status or approval.
Materials
Plain-English names for steel sections, roofing, walling, cladding and coatings.
Colorbond
A brand of pre-painted steel products commonly used for building components in Australia.
COLORBOND® steel is a branded, pre-painted steel product used for items such as roof and wall cladding, gutters and fascia. It is not a generic name for every coloured or coated steel product; when comparing materials, check the product named in the quote or specification.
Insulated Roofing
A special type of roof that helps keep patios and sheds cooler.
Insulated roofing combines roof skins or sheets with an insulating layer. Its thermal and acoustic performance varies by product, thickness, installation and site conditions, so those properties should be checked in the relevant product information.
Cladding
The outer sheet or panel material fixed over a building's roof or wall framing.
Cladding forms an external covering rather than the main load-carrying frame. Roof cladding and wall cladding have different locations and may use different profiles, finishes and fixing details.
Roofing
The materials and components that form the weather-facing roof covering.
In kit descriptions, roofing commonly means roof cladding or roof panels and may also refer more broadly to associated flashings and fixings. A quote or component list should identify exactly what is included.
Walling
The sheets or panels used to form a building's external walls.
Walling is another name commonly used for wall cladding. It is fixed to wall framing such as girts and is separate from the building's main structural frame.
Framing
The connected members that support a building and its roof or wall coverings.
Framing is the supporting arrangement of members such as columns, beams, rafters, purlins and girts. Main framing carries loads through the primary structure, while secondary framing supports components such as roof and wall cladding.
Coated Steel
Steel with a protective metallic, painted or combined coating applied to its surface.
Coated steel is a broad description rather than one particular brand or product. Coating systems, finishes and intended uses vary, so a product name and specification are more precise than terms such as coloured steel or coated metal.
Fascia
A finishing board or member along a roof edge, often associated with the gutter.
Fascia runs along a roof edge and can provide a finished face or support for associated components such as guttering. Its presence and structural role must be established for the particular building rather than assumed from appearance.
Patio Styles
The common patio designs available across Western Australia.
Attached Patio
A patio fixed to the home, typically using the house wall or fascia as one line of support.
An attached patio connects directly to the house, extending the existing roofline or attaching to the wall. It is the most common patio type for adding shade and outdoor living space close to the home.
Freestanding Patio
A self-supporting patio that stands on its own posts, independent of the house.
A freestanding patio is supported entirely by its own posts and is not attached to the home. This style suits pool areas, entertaining zones and locations away from the house, and gives more freedom in positioning and orientation.
Raised (Flyover) Patio
A patio set higher than the home's existing roofline to allow extra height, light and airflow underneath.
A raised or flyover patio is mounted above the existing gutter line, creating a higher, more open feel and allowing more natural light. It suits sloping blocks, second-storey clearances and larger entertaining areas.
Gable Patio
A patio with a pitched, triangular roof that creates extra height, ventilation and a feature roofline.
A gable patio has a pitched roof that rises to a central ridge, creating a sense of space and improving airflow. Gable designs are one of WA's most popular patio styles for larger outdoor living areas.
Roof Pitch
The amount and direction a roof surface slopes.
Roof pitch describes the slope of a roof surface. It influences the roof profile, the direction water travels and, for pitched forms, the relationship between the roof edge and ridge or apex; the suitable pitch is project- and roofing-specific.
Gutter Height
The level of a roof gutter at the roof edge, rather than the clear space below a patio.
Gutter height identifies the level of the gutter at a roof edge. It is not automatically the same as eave height, attachment height, beam underside, usable headroom or the roof's ridge or apex.
Eave
The part of a roof that projects beyond the outside wall.
An eave is the overhanging roof-edge area beyond an external wall. It can include or sit near fascia, gutter and the underside lining, so drawings or measurements should identify the exact feature being referenced.
Ridge
The upper line where two sloping roof planes meet.
A ridge is the high line formed where sloping roof planes meet, as on a gable roof. It is different from an edge or gutter level and may not apply to every roof form.
Headroom
The usable clear vertical space beneath a roof, beam or other overhead part.
Headroom is clear space available below the lowest relevant overhead component. It is not the same as gutter, eave, attachment, ridge or apex height, and the controlling component depends on the complete design.
Buying
The terms you will see on quotes and in DIY kit packages when comparing suppliers.
Factory Direct
Buying a kit directly from its manufacturer rather than through a separate retailer.
Factory direct describes the sales path, not the contents, price or engineering status of a kit. Compare the written inclusions, exclusions, documentation and total quoted cost when assessing different offers.
DIY Kit
A package of patio or shed components intended for the customer or chosen trades to assemble.
DIY describes who arranges or carries out assembly; it does not guarantee that every component, approval or engineering document is included. The quote, component list, drawings and instructions define the package and any project-specific requirements.
Approval Information
The information on this page is only a general guide.
Rules about building permits, planning approval and owner-builder requirements can be different depending on where you live and the type of project you are building. These rules can also change over time.
Before you order or build your patio or shed, check with the relevant local government, permit authority or an appropriately qualified building professional about what applies to your property and project.
Key Facts
- WA spans several wind regions, from the lower-wind south-west to higher-wind coastal and cyclonic zones.
- Wind region and terrain category are among the project inputs used to establish wind design actions.
- Engineer certification has a defined scope and does not itself grant planning or building approval.
- Z purlins are cold-formed steel members used as secondary framing to support a shed's roof and wall cladding.
- COLORBOND® steel is a brand of pre-painted steel, not a generic term for every coated steel product.
- A DIY kit's inclusions and documentation are established by its quote, component list and project documents.
Key Takeaways
- Wind region and terrain category are among the inputs considered when a patio or shed is designed for a particular site.
- Engineering documentation and approval requirements depend on the project, site and relevant authority.
- Roof cladding, wall cladding and framing are different parts of a building; a quote should identify what is included.
- Shared terminology helps you compare written inclusions, but similar descriptions do not prove that two kits are equivalent.
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