{{ propApi.closeIcon }}
Our industry
Our industry $vuetify.icons.faArrowRight
Housing industry insights Economics Insights Data & forecasts Tailored research and analysis Advocacy & policy Advocacy Policy priorities Position statements Submissions News and inspiration Industry news Member alerts Media releases HOUSING Online
Business support
Business support $vuetify.icons.faArrowRight
Become an apprentice host Hire an apprentice Why host a HIA apprentice? Apprentice partner program Builder & manufacturer program Industry insurance HIA Insurance Services Construction works insurance Home warranty insurance Tradies & tool insurance Member perks Toyota vehicles The Good Guys Commercial Fuel savings See all Planning & safety solutions Building & planning services Safe Work Method Statements (SWMS) Solutions for your business Contracts Online Advertise jobs Trusted support & guidance Contracts & compliance support Industrial relations
Resources & advice
Resources & advice $vuetify.icons.faArrowRight
Building it right Building codes Australian standards Getting it right on site See all Building materials & products Concrete, bricks & walls Getting products approved Use the right products for the job See all Managing your business Dealing with contracts Handling disputes Managing your employees See all Managing your safety Safety rules Working with silica See all Building your business Growing your business Maintaining your business See all Other subjects Getting approval to build Sustainable homes See all
Careers & learning
Careers & learning $vuetify.icons.faArrowRight
A rewarding career Become an apprentice Apprenticeships on offer How do I apply? Frequently asked questions Study with us Find a course to suit you Qualification courses Learning on demand Professional development courses A job in the industry Get your builder's licence Continuing Professional Development (CPD) Further your career Find jobs
HIA community
HIA community $vuetify.icons.faArrowRight
Join HIA Sign me up How do I become a member? What's in it for me? Mates rates Get involved Become an award judge Join a committee Partner with us Our initiatives HIA Building Women GreenSmart Kitchen, bathroom and design hub Get to know us Our members Our people Our partners Support for you Charitable Foundation Mental health program
Awards & events
Awards & events $vuetify.icons.faArrowRight
Awards Awards program People & Business Awards GreenSmart Australian Housing Awards Awards winners Regional Award winners Australian Housing Award winners 2024 Australian Home of the Year Enter online Industry events Events in the next month Economic outlook National Conference Events calendar
HIA shop
HIA shop $vuetify.icons.faArrowRight
Most popular products National Construction Code Vol 1 & 2 Waterproofing wet areas AS 3740:2021 HIA Guide to Waterproofing HIA Guide to NCC Livable Housing Provisions Top categories Building codes & standards Contracts & documents Guides & manuals Safety documents Signage For your business Contracts Online Digital Australian Standards Digital Resource Library Forecasts & data
About Contact Newsroom
$vuetify.icons.faMapMarker Set my location Use the field below to update your location
Change location
{{propApi.text}} {{region}} Change location
{{propApi.successMessage}} {{region}} Change location

$vuetify.icons.faPhone1300 650 620

Using AS 1684 for timber framing

How should AS 1684 Residential Timber Framed Construction be interpreted for installation of residential timber – and which part of the Standard suits your needs?

AS 1684 – Four parts

AS 1684 Residential Timber Framed Construction has four parts: 

  • Part 1 relates to design criteria that can be used as a basis for the preparation of span tables and design data for the other parts. This is the document commonly used by engineers 
  • The other three parts provide building practices and procedures that assist in the correct specification and determination of timber members, bracing and connections. Part 2 and 4 are used in non-cyclonic areas and Part 3 is designed for the cyclonic areas of northern Australia. Part 4 is referred to as the ‘Simplified’ version.

As the name suggests, Part 4 being the ‘simplified’ version was developed as a more user-friendly document than Part 2. But there are differences between the two Standards that users must be aware of that places limitations on the simplified version.

The criteria in both versions are specifically for conventional timber-framed buildings of one or two storeys.

Part 4 can only be used in the two lower wind classifications of N1 and N2 where Part 2 covers wind classifications up to N4.

The maximum width of a building designed under Part 4 is 12m where Part 2 can be used for building widths up to 16m and maximum external wall heights are 2.7m and 3m respectively.

There is a limit placed on the maximum roof pitch in both documents of 30 degrees for Part 4 and 35 degrees for Part 2.

To assess the amount of bracing a building requires under Part 4 only requires four steps, the bracing units are expressed as type A or type B and a simple table will indicate how many units are required.

Part 2 is a lot more complex in relation to bracing calculation and requires the raking forces to be determined and the calculation of bracing expressed in kilo Newtons per metre designed to counter that force.

The simplified version is popular for its hard copy span tables and minimal information is required to determined spans. Part 2 has supplementary span tables on CD that requires more input to calculate timber sizes but delivers more choice.

The disadvantage of using Part 4 is that it generally over-engineers building components, the span tables are less comprehensive and can be less economical to use than Part 2, so this should be considered when deciding which part to adopt. 

To find out more, contact HIA's Building Services team.

Email us

Share with your network:
More articles on:
{{ tag.label }} {{ tag.label }} $vuetify.icons.faTimes
Find the latest expert advice, guides and much more!

Building it right topics


Can’t find what you need, check out other resources that might be closer to the mark.

Start learning
View all $vuetify.icons.faArrowRight
22 Jul
CPC30220 Certificate III in Carpentry

This qualification provides the essential skills required to gain a trade in carpentry, covering work in both residential and commercial applications.

22 Jul
Asbestos Awareness

Gain a basic awareness of asbestos - where it may be found; its health hazards; and the safety control measures that should be applied to prevent exposure of workers and others.

25 Jul
NCC 2022: AS1684 Timber Framing Changes

Gain an overview and understanding of the changes to AS1684 Timber Framing Code.

26 Jul
Essential Elements of Roof Framing Trusses in South Australia

This course is designed to provide knowledge on the correct use and understanding of wall and roof framing plans specifically in South Australia.

Carports & Pergolas - Design & Construction Manual

This construction manual is suitable for any design and construction work with timber carports and pergolas. It contains clear and concise information to help in the building of flat or skillion-roofed carport structures that supp...

Hancock's Roof Cuts & Rafter Lengths

Hancock’s Roof Lengths and Rafter Lengths is well known throughout the building industry as the Little Red Roofing Book. No self-respecting roofer should be without it. It’s an easy-to-read, handy-sized pocket guide to roof constr...

Pocket Span Table Book

The Pocket Span Table Book comes in an easy-to-carry, pocket-sized (A5), durable book in a spiral-bound format. It includes span tables for commonly used sawn structural timber grades, as well as engineered LVL and I-Beam floor jo...

Timber Decks Design and Construction Manual

The Timber Decks Design and Construction Manual is an illustrated guide to the design and construction of low-maintenance timber decks for domestic applications. This is a hard copy version of the manual and will be mailed to you...