Duplex builder in Ermington

We know Ermington well. Our base in Rydalmere is right next door, and we recently designed and built an attached duplex here, completed in late 2024. AGA Building is a family-run, licensed builder, and Andrew supervises every job on site from demolition to handover.

Can you build a duplex in Ermington?

Ermington is in the City of Parramatta, and much of it is zoned R2 Low Density Residential, where duplexes are allowed. The suburb already has plenty of them. In the 2021 census, about one in five Ermington homes was semi-detached.

Ermington doesn’t have a train station or one of the town centres covered by the NSW Low and Mid-Rise Housing Policy, so the City of Parramatta’s own minimums apply:

Control	Ermington (Parramatta LEP 2023)
Minimum lot size for a duplex	600 m²
Minimum lot width	15 m

Many of Ermington’s homes date from the years after World War II, and a lot of those blocks are big enough for a duplex. If your block is a little under 600 m² or 15 m wide, it’s still worth asking. A DA can sometimes allow a small variation.

What we check on Ermington blocks

• Flooding. Ermington runs down to the Parramatta River, and Subiaco Creek flows through the suburb, mostly in a pipe. Blocks near the river or the creek line can be flood-affected, which changes floor levels and design.
• Slope and drainage. Streets falling toward the river often need careful stormwater design.
• Pipes and easements. Stormwater pipes and sewer lines running through backyards can limit where the homes go.
• Corner and wide blocks. These can sometimes fit two detached homes, or two homes facing different streets.

CDC or DA in Ermington?

A regular block that meets every standard and isn’t flood-affected may suit a complying development certificate (CDC), which is usually faster. Flood-affected blocks, undersized lots and designs that need some flexibility go through a development application (DA) to the City of Parramatta. We work this out at the start and manage the approval for you.

Our Ermington duplex

Our Ermington duplex is an attached pair of two-storey homes, each with its own garage, kitchen, ensuite, main bathroom and powder room, finished to the same standard in both homes and completed in late 2024. We handled the design, approval and construction. We’ve also built duplexes next door in Rydalmere and nearby in West Ryde.

How we build your Ermington duplex

1. Free block check. Zoning, flooding, lot size, width and any red flags.
2. Design. Plans that suit your block and your goals, whether you live in one home, sell or lease.
3. Approval. CDC or DA, including flood and stormwater reports if needed.
4. Demolition and construction. Andrew runs the site, just minutes from our base.
5. Handover. A final walkthrough, with every certificate and warranty document.

Ermington duplex questions

How do I know if my block is flood-affected?

A Section 10.7 planning certificate from the City of Parramatta shows whether flood controls apply. We check flood information as part of our free block check.

Can I live in one home and sell or rent the other?

Yes, that’s a common plan in Ermington. A duplex can usually be subdivided so each home has its own title, and we can plan the design around it.

What will an Ermington duplex cost?

It depends on the size, finishes and any flood or drainage requirements. Our duplex cost guide covers the main costs, and we’ll give you a realistic budget once we’ve seen the block.

General information, current as of October 2026. Planning controls change, so always confirm the rules for your property with the City of Parramatta or a certifier. Source: City of Parramatta – Low and Mid-Rise Housing Policy.