Residential building design project Williamstown, Melbourne western suburbs

Registered building designer for Williamstown properties

Design and permits for extensions, rebuilds, and secondary dwellings in Williamstown. One practice, start to finish.

Getting the design right on a coastal property takes local knowledge and planning experience. RD Building Design is a registered building designer working across Hobsons Bay, managing everything from initial concept through to approved permit drawings.

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Who is RD Building Design?

Rhys Davies Building Designer (DP-AD 43008) Adv.Dip. Building Design (Arch.), Registered Building Practitioner (Arch.) RD Building Design

A registered building design practice based in Melbourne's western suburbs, working across Hobsons Bay and neighbouring councils.

We specialise in residential projects: extensions, granny flats, dual occupancy, knockdown rebuilds, and new homes. One designer leads your project from start to finish.

Straightforward communication, realistic timelines, and permit documentation that is right the first time.

Curious about the difference between a building designer and an architect?

Heritage overlay design in Williamstown

A heritage overlay does not mean you cannot build. It means the design needs to respond to the existing character of the property and its surroundings.

Extensions, secondary dwellings, and alterations in heritage areas proceed through planning permission. The design needs to sit comfortably alongside the original building without copying it.

RD Building Design works within Hobsons Bay's heritage provisions and can advise at the outset what approvals your property requires under the Hobsons Bay Planning Scheme.

Dual occupancy design in Williamstown

Dual occupancy is realistic for Williamstown homeowners with blocks in the right zone and of sufficient size. A two-lot subdivision typically requires a design meeting ResCode requirements, adequate frontage, and landscaping considerations.

The planning process is more involved than for extensions or granny flats, but the outcome, two separately titled properties, is substantially different financially.

RD Building Design carries out dual occupancy feasibility assessments at initial consultation. We review block size, zoning, and planning provisions before any design work, so you know whether the project is viable before committing.

Extending on a smaller Williamstown lot

Compact blocks require careful design. Every square metre of extension affects setbacks, site coverage, and overlooking provisions. What you gain in one area, you often give up in another.

The skill is in finding the layout that gets the most from the site while staying within the Hobsons Bay Planning Scheme controls. RD Building Design works on tight western suburbs sites regularly and knows where the constraints have flexibility.

What you can build in Williamstown

Planning controls and development potential under the Hobsons Bay Planning Scheme

Council

Hobsons Bay

Planning scheme

Hobsons Bay Planning Scheme

Predominant zones

NRZ Neighbourhood residential zone

Limits housing growth. Maximum two dwellings per lot in most cases. No apartment-style development. Protects established neighbourhood character.

GRZ General residential zone

Allows moderate housing growth. Dual occupancy viable on lots of 300sqm+ per resulting title. Medium density development permitted with a planning permit.

Planning overlays

Heritage overlay

Heritage overlays apply to parts of this suburb. Works visible from the street typically require a planning permit. Rear additions may be exempt depending on the specific overlay schedule.

Flood overlay

Land subject to inundation overlay (LSIO) applies to some areas. Minimum floor levels and drainage requirements affect design. Site-specific checking required.

Typical lot size

Small to medium (typically under 500sqm)

Site coverage is frequently the binding constraint. Extensions and secondary dwellings need careful positioning to stay under the 60% site coverage limit.

Granny flat viability

Permitted up to 60sqm without a planning permit under Victoria's 2023 provisions, but site coverage is likely to be the binding constraint. Many blocks can accommodate a secondary dwelling if existing building footprint allows.

Dual occupancy

Viable on selected lots

Some GRZ zoning available, but NRZ dominates or lot sizes limit opportunities. Feasibility depends on specific block dimensions and frontage.

Location

11km from Melbourne CBD. Nearest station: Williamstown.

This summary reflects general planning conditions for Williamstown as of 2025. Individual properties may have additional overlays or conditions. A property assessment confirms exactly what applies to your block.

Building design services in Williamstown

Whatever your project RD Building design can help.

New home design

Custom home design from initial brief through to permit-ready documents

Knockdown rebuild designs

A completely new design on your existing block, built around the life you want

Residential extensions and renovations

Additions that connect and blend with your existing home

Townhouses / Multi-Unit design

Multiple dwellings on one site, with all planning and documentation managed

From first conversation to approved plans

RD Building Design manages the full process.

Consultation. We discuss the project, review your Williamstown property, and outline what is possible. No charge.
Feasibility. Goals tested against site conditions and planning controls. Done before design starts.
Concept. Floor plans and external design showing how the project works on your block. You guide the revisions.
Planning permit (where needed). Full application prepared and managed through Hobsons Bay assessment.
Permit drawings. Working drawings for building permit and builder quoting.
Completion. A full set of approved drawings, ready for construction.

RD Building Design serves homeowners across Melbourne's western suburbs and beyond.

Building design questions for Williamstown homeowners

Will I need a planning permit to extend in Williamstown?

That depends on the scope of the work and any overlays on your property. Many standard extensions go straight to building permit. Heritage or design overlay areas typically need planning approval first. We check this at your initial consultation.

What is the typical permit timeline in Williamstown?

Building permits are usually assessed in around 10-20 business days. If a planning permit is needed, Hobsons Bay generally takes about 10-60 days. RD Building Design provides realistic timelines at the outset of every project.

Is a granny flat possible on my Williamstown block?

Under Victoria's 2023 reforms, a secondary dwelling up to 60sqm can be built on most NRZ and GRZ lots without a planning permit, provided site coverage, setback, and open space requirements are met. We assess this as part of an initial consultation.

Can I subdivide my Williamstown property for dual occupancy?

Dual occupancy requires adequate lot size, and sufficient frontage. RD Building Design assesses feasibility at the initial consultation stage.

How does heritage affect my extension in Williamstown?

Heritage overlays shape the design approach but do not prevent extensions. RD Building Design works within Hobsons Bay's heritage provisions and can advise on what approvals are needed for your property.

Can I add a second storey in Williamstown?

Usually, yes. The main considerations are the existing structure's load capacity and planning controls around overlooking, overshadowing, and character. RD Building Design checks both at concept stage.

How can I find out what is buildable on my Williamstown property?

A property assessment from RD Building Design reviews your block against the Hobsons Bay Planning Scheme and provides a written summary of development potential, including extension capacity, granny flat viability, and dual occupancy options.

Ready to talk about your Williamstown project?

Book a free consultation and we will review your property, discuss your goals, and give you an honest picture of what is possible.

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