Engineering On Demand
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/ Granny Flats Perth

Design, Engineering & Approvals for Granny Flats

Planning a granny flat in Perth?

Engineering On Demand provides the professional services required to take Granny Flats Perth projects from an initial concept through design, structural engineering, building certification and council approval.

Whether you’re building a custom granny flat, installing a prefabricated unit or working with a builder, our team can coordinate the technical documentation needed to get your project ready for approval and construction.

From Granny Flat Design Perth and engineering through to Granny Flat Approval Perth, you can deal with one experienced team instead of coordinating multiple consultants yourself.

Granny Flat Design & Engineering

Plans, Certification & Documentation

Council Approval Support

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Tell us about your project.

Engineering Your Granny Flat From the Ground Up.

A granny flat is still a dwelling and needs an appropriate structural solution for its site, construction system and design.

As your Granny Flat Engineer Perth, Engineering On Demand can provide structural engineering for the major elements of the building, including:

  • Footings and foundations
  • Concrete slabs
  • Structural framing
  • Beams and lintels
  • Columns and posts
  • Structural steelwork
  • Timber framing
  • Roof structures
  • Bracing
  • Structural connections
  • Site-specific structural details

Our engineers work alongside our drafting and approval team so the structural design can be coordinated with the wider project documentation.

GRANNY FLAT DESIGN PERTH.

What May Need to Be Engineered?

Good granny flat design needs to balance available space, functionality, construction requirements and the applicable planning and building requirements.

Our Granny Flat Design Perth services can help develop the documentation required to move from an idea to an approval-ready project.

Depending on the project, this may include:

Site Assessment.

Reviewing the property, available space and relevant site constraints.

Site-Specific Drawings.

Preparing plans appropriate to the proposed granny flat and property.

Structural Engineering.

Engineering the foundations, framing and other structural elements.

Technical Documentation.

Preparing the information required to support certification and approvals.

Coordination.

Bringing together the different consultants and documents required for the project.

GRANNY FLAT APPROVAL PERTH.

Do Granny Flats Need Council Approval?

Planning / Development Approval

Under WA’s current R-Codes, a compliant ancillary dwelling on residential land may be exempt from planning approval if it meets the relevant requirements, including the applicable development standards and a maximum internal floor area of 70 m².

Building Permit

Being exempt from planning approval does not mean you can simply start building.

A building permit is still required for an ancillary dwelling. Local government guidance also confirms that planning approval may be required where a proposal doesn’t qualify for the applicable exemption.

This distinction is important.

NO DEVELOPMENT APPROVAL REQUIRED ≠ NO BUILDING APPROVAL REQUIRED

Engineering On Demand can assess the proposed project and help determine the appropriate approval pathway.

WA Government – Residential Design Codes

 

THE 70m² GRANNY FLAT RULE.

More Opportunities for Granny Flats in WA

Changes to Western Australia’s R-Codes significantly expanded opportunities for ancillary dwellings.

The WA Government confirms that R-Code-compliant granny flats can be constructed on residential lots of any size without planning approval where the applicable requirements are satisfied and the granny flat does not exceed 70 m². The current R-Codes also provide for granny flats on residential land including grouped and multiple dwelling sites and strata lots.

That doesn’t mean every granny flat automatically qualifies.

Factors such as setbacks, site conditions, design and the applicable planning framework still need to be considered.

We can review your proposed project before detailed documentation begins to identify the likely approval pathway.

 

Every Granny Flat Has to Sit on Something.

Before an appropriate foundation system can be engineered, the site’s ground conditions need to be understood.

A site classification provides information used when determining the footing and slab requirements for residential construction.

Depending on the granny flat system, the structural solution may involve:

  • Concrete slabs
  • Strip footings
  • Pad footings
  • Pier systems
  • Proprietary footing systems
  • Engineered supports for transportable structures

Our engineers can develop a foundation solution appropriate to the building and available site information.

Frequently Asked Questions.

Under the current WA R-Codes, the relevant maximum internal floor area for an ancillary dwelling on residential land is 70 m². Other development requirements still apply.

Not necessarily. A compliant granny flat may be exempt from planning approval where it meets the relevant R-Code requirements. Projects that don’t satisfy the applicable requirements may require planning approval.

Yes. Planning exemption should not be confused with building approval. A building permit is still required for an ancillary dwelling.

Structural engineering may be required for elements including foundations, slabs, framing, beams, bracing, structural connections and site-specific installation requirements.

Yes. Our Granny Flat Plans Perth services can provide project documentation and coordinate it with structural engineering and approval requirements.

Yes. We can review available manufacturer documentation and determine the site-specific structural engineering required for the proposed installation.

Yes. Where included in our scope, we can prepare and coordinate the required documentation and submit the relevant application to the local government on the client’s behalf.