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How to plan your perfect home extension

Have you ever wondered:

• What is involved in getting your ideas to council approval?
• What do you need to do?
• Who do you need to ask or engage?
• Do you have to talk with the council?

We are going to cut through the noise and answer all your questions about planning your home extension.

It may all seem daunting at the start but there is a process you can follow to create your dream home. There are six distinct phases involved in designing your home and preparing it for construction. Here’s  everything you need to know about working with Designer Home Extensions to extend your home.

1. Meet with us to discuss your vision for your home

We will meet together at your home to discuss your vision for your home and to make sure it aligns with the expertise that Designer Home Extensions can offer.

If you have a design brief, wish list, and/or a mood or vision board. Bring this to our meeting. It will definitely help me to explore your ideas. It will also allow me to see if it fits in with council guidelines and your home’s limitations. I will be able to see pretty quickly whether your ideas will be achievable within council guidelines.

2. Building Design and Documentation Fees

Once I have a good understanding of your extension needs, I will provide you with a proposal that outlines our fees. These will include not only our design fees but also any consultant fees (refer to building permit application below), council fees and any other items required. I will give you a detailed breakdown so that you know exactly what you are spending and when you are expected to spend it by.

When you’re ready to engage us to extend your home, we will complete the next steps.

3. Pre-Concept Design Research

At this stage, finding all the relevant information to your site and house prior to any design work starting is crucial. Knowing what your limitation sare is very important.

We will liaise with relevant council and confirm council guidelines and codes, character retention precincts and heritage listed areas.

We will also source information from Water Corporation for sewer line locations as well as ‘Dial Before You Dig’ DYBD for water, power, gas and telecommunications locations.

As the client, you may also have information from a previous owner or works undertaken yourself which can provide further documents to assist us with the design.

4.  Concept design

These concept design drawings are used to formalise your ideas on paper. They cannot be used for council lodgement. When we put our ideas onto paper along with our previous research, we can start to see what can and can’t be achieved.

If existing house plans are not available, it will require measuring the existing home. Even with existing plans, they often are in imperial measurements or not consistent with what has been built, so creating current as existing measured drawings is advised. Council archive searches are also an option, as they may have existing plans and documents regarding your house.

Feature site surveys are required for any proposed first floor additions or where the ground level varies/slopes as required by relevant council.

Now we use our magic to create your vision. 

We will be looking at the flow of your home, natural light and ventilation, architectural features and repurposing/creating new spaces based on your needs.

This will be achieved through floor plans, elevations, 3D images and/or video walkthroughs.

During this process, site information such as site area versus building area will be assessed. For example, ‘overlooking’ issues might arise if you’re doing a first floor addition, or if your ground floor is more than 500mm above natural ground level, this might also cause overlooking problems. 

Boundary setbacks could be an issue, and we need to make sure we get those right for council approval. You will have restrictions around your building and roof height maximums. All this will be taken into consideration at this stage.

During this phase, as your designer, we meet with the on-duty planning officer at your local council to make sure that the design we propose to you is within council regulations.

This step can potentially save you thousands of dollars and disappointment. 

If the council doesn’t agree with certain design components, we work with you to find a compromise that you’re happy with.

Once we present you with your preliminary concept design, there’s always an opportunity for you to make changes. As we always say: “It’s easier to change now on paper than when it’s being built or under construction”.

This is also a good time to get some ballpark figures of construction cost and talk to potential builders. We can also tender documents on your behalf (building permit documents).

5. Development Approval Application

The next step in the process is to submit certain documents to the council for development approval.

Some councils insist that you must meet with them before lodging your development application.

Other councils allow you to request a meeting or you can request written advice on your application. We recommend meeting with your council face-to-face where possible as it builds the relationship and makes your path easier.

When you are happy with the final concept design, these drawings can be developed to a Development Application standard.

Development Application drawings generally include:

• a site plan
• existing floor plan/s
• external elevations
• site information such levels, building and roof heights 
• overlooking or privacy issues
• materials and finishes
• sun shadow diagrams.

The following documentation is required for lodgment of your Development Approval:

• drawings as above
• Development Application forms
• Certificate of Title
• Feature Site Survey
• Development Application lodgement fees.

Depending on the council, the timeline for Development Approval ranges from 60 to 90 days.

6.  Building Permit Application

Once your Development Application (DA) is approved, we must adhere to any conditions that have been itemised on the Approval. 

If there are changes required to the DA, you will need to resubmit the application as an Amended Plans Application.

Once your Development Application is approved, it is time to pull out the champagne and celebrate!

After DA approval, we will work towards providing more technical building information to comply with the Building Code of Australia (BCA) and Australian Standards (AS). This all forms part of the Building Permit Application.

Working Drawings

As part of the Building Permit Application, your Development Application drawings will be further developed to ‘Working Drawings’ standard, which requires the provision of additional information, including:

Site plan: proposed addition, boundary setbacks, soak well sizes and locations, driveways and crossovers

Floor plan: existing and proposed addition and alterations, room and overall dimensions

Elevations: external elevations showing window and door heights;,ground levels, roof material and pitch, gutters, wall and roof height

Detail Section: larger section drawing showing connection between existing house and proposed addition or upper floor

Internal wall elevations: wet areas such as kitchens, bathrooms, laundries showing cabinetworks, wall tiling layout and extent, fixtures and fittings

Electrical plan: placement of electrical fixtures and fittings such as lights, power points, switches, data points, exhaust fans, smoke detectors

Consultant Drawings

During the Building Permit Application phase, other consultants need to be engaged to complete the lodgment of the following documents:

Engineering drawings: Structural plans and detailing including concrete slab and footings, masonry walls, structural steel construction, timber wall and roof framing, connection details.

Energy Assessment: Assessing the thermal efficiency of your existing house and proposed addition/s.

Building Certification: Independent building certifier assesses all the documentation required for building permit against the BCA and council, the certified application takes roughly 10 working days and the uncertified application takes roughly 25 working days.

BAL statement and/or reports: If the property is in a Bushfire Prone Area, a Bushfire Attack Level (BAL) statement and/or report needs to be provided. 

For Submission of your Building Permit Application, your Council will Require:

• working drawings
• consultant drawings
• Building Permit application forms.
• Building Permit lodgement fees.

Building Permit Approval – Yay!

You have the green light to build!

It usually takes around six months from the time you engage your designer, right through to Building Permit Approval.

Usually, half of this time is spent waiting for council approvals.

Be sure to allow yourselves this amount of time, if you have a tight time schedule.