Some terms relating to Construction and Building Elements are:
Footings: Houses, sheds, garages, etc need to have adequate foundations to support them and reduce the risk of damage occurring to the structure. Footing types can be either isolated (pad) footings, strip footings, Raft Slab footings, Waffle Slab footings (using polystyrene blocks under the slab), special suspended slabs, and also footings to take account of poor ground conditions such as filled sites and sites affected by Mine Subsidence.
There is an Australian Standard for Footing Design that is referenced in the Building Code of Australia. This standard is AS2870 – Residential Slabs and Footings, with the current revision being issued in 2011. This code details dimensions, reinforcement details, layouts and construction constraints for various types of footing construction.
The required type of construction is dependant upon the type of ground encountered on the site, that is in turn specified by a Geotechnical Engineer following site testing of your lot (Refer to previous blog post for further details). Site Classifications defined in the Standard can generally be grouped loosely into the following types of soil:
- Class A – Rock
- Class S – Sand
- Class M – Moderately reactive Clays
- Class H1 – Highly Reactive Clays
- Class H2 – More Highly Reactive Clays
- Class E – Extremely Reactive Clays
- Class P – Problem Site, e.g. Filled Sites, Sites subject to Mine Subsidence
The type of site (or the Site Classification) is specified by the Geotechnical Engineer and is based on the results of their testing. Different site classifications may also limit the type of construction that you are able to build on the site. For instance, cavity brick construction is not generally allowed on Class H2 Sites due to the risk of footing movement damaging the brick walls. Our next Blog post will go into more detail on the benefits of various types of footing systems.
Following on from our recent post, some more terms used in the Building process are:
Council Certifier: A Council Certifier (or Building Inspector) is employed by your Local Council to perform the same tasks as a Private certifier. They will inspect various stages of the building construction and then provide Certification on completion that the building works comply with the Approved Plans and Specifications.
Prior to 2000, Council Building Inspectors were the only people approved to inspect and certify works. Following the introduction of Private Certifiers, responsibility has been moved away from Local Council with more developers choosing to use Private Certifiers for their projects. Most inspections and certifications are now carried out by Private Certifiers (2019)
Geotechnical Engineer: A Geotechnical Engineer will carry out investigation (usually by drilling bore-holes) on your site, and provide a report that will determine the “Site Classification” of the soil on your site. This Site Classification will then allow the Structural Engineer to prepare a footing design that suits the specific conditions on your site. Footing designs need to be carried out either in accordance with the specifications set out in the Australian Standard AS2870 – Residential Slabs and Footings, or in accordance with Engineering Design principles.
In any case, the Structural Engineer needs to know what the ground is like that the building will be sitting on. They need to know if there is rock underlying the site that may make excavation difficult, if there is sand, or if there are clays on site that may expand and contract depending on moisture conditions (ie, clays will contract during period of dry weather). Each of these different soil types will require different footing designs to ensure that the building will remain stable and will reduce the likelihood of damage occurring to the structure.
This list is a brief introduction to some terms used in the planning, approval, and building of your home or renovations.
Local Council: Your Local Council will need to approve of any development or construction work carried out on your site. They will need plans and specifications prepared showing what the works are that you are planning, whether it is a small extension, a new family home, or a multi-unit development. Depending on the complexity of the works, you may be able to provide a simple hand-drawn plan showing your works. Otherwise either an Architect or Draftsperson will need to prepare plans to the required standard for Council Submission.
Architect: A person with a University Degree in Architecture. These people or firms are generally experienced in preparing design drawings for houses and renovations. They will usually meet with you and discuss what your ideas are. They will then prepare plans for your review and will revise as needed. They are familiar with Local Council development guidelines and will ensure that what you wish to do complies with relevant requirements. If required they can provide a cost estimate for your development, and even carry out construction supervision and project management for the building. Architects are sometimes portrayed as producing “fancy” designs (not your normal project home style building).
Draftsperson: These people are usually less qualified than Architects and will provide various levels of detail in preparing your plans. For smaller or more straight-forward projects they can be more cost effective than Architects. They will prepare plans to comply with Local Council guidelines. They are generally less expensive than Architects. They are usually more suited to preparing drawings for more conventional “standard style” buildings or renovations.
Structural Engineer: They are Engineers with a University Degree in Civil or Structural Engineering. They will generally have experience in different types of construction, with some engineers focussing on residential developments, some on Commercial developments, and others on Industrial Buildings. Residential construction can range from simple additions, to new houses, multi-unit town houses, and multi-story apartment buildings. Structural Engineers will need to design such elements as footings, beams, frames, retaining walls, etc. These elements will need to be signed off to ensure that they are structurally adequate and safe, and will be required prior to obtaining Council approval for your project. You should ensure that your Structural Engineer is competent in the types of works you are carrying out, has adequate Professional Indemnity insurance in case something goes wrong, and that they are a Member of the Institution of Engineers Australia. Depending on which state our are building in, the Engineer may also require additional State-Specific Certification (ie, Registered Professional Engineer of Queensland (RPEQ), Victorian Building Authority (VBA) Membership in Victoria, etc)
Private Certifier: During construction, various building elements will need to be inspected and certified to ensure that the construction matches the design plans. Such things as footings, frames, waterproofing, drainage, and plumbing need to be inspected during the works. This is the role of Council or alternatively a Private Certifier.
Once you have obtained your Development Approval from your Council, you must decide whether you will engage the Council or a Private Certifier to prepare your Construction Certificate (your “CC”) and carry out the require inspection, before you commence building.
The Private Certifier will inspect your works at various stages to ensure that the works are in accordance with the Architectural plans, Engineers’ details, and other requirements. At completion of the project, they will issue Certification that the works have been carried out in accordance with the Approved Plan, Engineers Details, etc. They will then issue an Occupation Certificate for the works, and you can move in or sell the property without any issues.
To be continued……
Now that you made the decision to build a new house. You now have a few decisions to make.
Choose a Builder: Who is going to build the house? Are you going to use a Project Home builder? Are you going to engage a Licensed Builder to build it? Are you going to Owner Build it and organise all the trades yourself? Each of these scenarios will require different approaches.
If you engage a Project Home type of builder, they will prepare all plans, specifications, engineering details, and usually Local Council submission and approvals. You then don’t need to engage an Engineer yourself.
If you are going to use one of the other methods, then you will need to arrange the following:
Architectural Plans – These detail the size, appearance, position on the site, and dimensions of the house. These can be prepared by an Architect or Draftsperson, with enough detail to show the Council what the house will look like, where it is located, and any other information required.
Council Submission and Approval – This is required prior to commencing Construction. Generally you will first need to obtain a Development Approval from your Local Council which will detail Local Government requirements, planning restrictions, based on the plans you have provided. This does not need to be fully detailed, with all dimensions etc on them. It is a good idea to show if possible any external buildings (ie, garage, pool, etc) that you may be considering building in the future even if you are not building them to start with. Once you DA is approved and construction has commenced, your approval will remain in place indefinitely, thus reducing any future issues with changes in planning policies.
Once you receive your Development Approval from the Local Council, you will then need to prepare more detailed plans for the Construction Certificate (CC) application. This CC can be assessed and approved either by your Local Council, or a Private Certifier. It is up to you which one to use. Sometimes using a Private Certifier can be easier and quicker as they will guide you thru the CC and construction process. The Certifier (either Council or a Private Certifier) will monitor and inspect the works during construction to confirm that they comply with relevant designs, codes, specifications, and designs, and on completion will provide a certification called an Occupation Certificate that confirms that the building has been built correctly in accordance with the approval.
Engineering Plans and Specifications: You will need Plans and Specifications for such things as concrete footings & slabs, beams, frames, etc. These things you need can be assessed by an Engineer based on your Architectural Plans, and can be commenced before you receive Council Approval. This is where we come in, and we can provide initial advice and a quote for supplying Engineering Plans and Specifications for your project. Contact us on 02 49886111 or go to the link on the webiste.
This is just a brief overview of the process, and there may be additional items required depending on your specific design, Local Council, or other planning requirements.
When Building or Renovating, there are many tasks that need to be carried out, approvals to be sought, plans to be prepared, and finally builders to be engaged and construction carried out.
In general, if you are thinking of Building a New Home or Renovating your existing house, you will need to carry out most of the following tasks:
- Engage a draftsman or architect to prepare plans for your new house or renovation.
- Submit plans to your Local Council showing what you are intending to do.
- Obtain Development Approval (a “DA”) from your local Council in relation to your development.
- Obtain any other approvals needed for your area (ie, Hunter Water, Mine Subsidence, etc)
- Pay Council and other Fees required.
- Engage a Structural Engineer to prepare details for such things as footings, retaining walls, beams, and frames.
- Apply for a Construction Certificate (a “CC”) from either your Local Council or a Private Certifier to allow construction to commence.
- Obtain quotes from Builders for the proposed works.
- Select a Builder to carry out the works, or if you are confident in managing trades-people you can obtain your Owner Builders Licence and build it yourself.
You should seek advice from your Architect or Drafts Person on the best way to proceed, whether you owner-build or engage a builder. Generally, Owner Building is seen as being less expensive than engaging a Licensed Builder, as you do not pay for the builders mark-up on trades and materials. However, depending on how confident you are of managing a building project, it can take longer and end up being more expensive than if you had engaged a builder.
Structural Engineers can also provide advice during the initial stages. Sometimes your architect or drafts person will use an Engineer regularly that they will discuss various aspects of your design with. Sometimes they leave the structural aspects of the building to the Builder to sort out.
If you are going to get quotes from Multiple builders, then to receive competitive, accurate quotes you will need to provide the builder with as much information as possible, including Structural Engineers details.
Paul Clarke and Associates can provide advice and designs on all aspects of your development, and work regularly with builders, architects, and Draftspeople to assist in preparing plans for your development. For more information please contact our office on (02) 4988 6111, or via email at email@example.com (or via the link on this website)
Structural Engineers are experienced in providing advice, designs, plans, and specifications for all of the Structural aspects of your house, extension, shed, or retaining walls.
If you are looking at building a new house, carrying out extensions, renovating the inside of your house, or excavating your yard, you need to seek advice from a Structural Engineer to ensure that what you want to do is stable, safe, and will support loads that will be imposed on it. Your Local Council or Private Certifier will also require Engineering Certification of various aspects of your project to ensure that it complies with relevant Regulations and Australian standards.
As Structural Engineers with over 30 years experience, Paul Clarke & Associates can provide advice and specifications on anything you want to do to your house, shed, yard, or commercial property.
For further advice please contact us via our Contact details page.