
Licensed Home Extension Builder Mays Hill
NSW licensed extension specialist. Mays Hill 2145 extensions on 1950s–1970s-era homes require structural sign-off, Class M footings, and matched connection — we engineer and document properly.
Quick Answer
A home extension in Mays Hill costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, Cumberland City Council approvals, and construction under one fixed-price contract.
Second-Storey & Rear Additions in Mays Hill
Mays Hill sits between Parramatta and Merrylands — proximity to Parramatta CBD makes extension here a strong investment. Add living space to an established home on R2 land. Cumberland City Council approvals managed by Buildana.
For a extension in Mays Hill, the economics are the framing question. Median price $1.0M–$1.3M; build cost on 450–650m² blocks scales by site conditions and specification. Class M ground (moderately reactive) keeps foundations honest — $15,000–$32,000 band — and blowouts on that line are the single most common reason fixed-price contracts elsewhere don't stay fixed. Buildana itemises the slab, structural engineering, and geotech work upfront so you see the actual cost in the contract. R3 zoning in pockets of Mays Hill opens up dual occupancy potential — worth exploring even if you're not initially considering it.
Buildana manages the complete home extension process in Mays Hill — from design consultation and structural engineering through to DA or CDC approval, and fixed-price construction to handover. Extend your home without the stress.
Read our Home Extension Cost Guide 2026 or explore extension approval pathways in NSW.
- Home extensions in Mays Hill from $150K
- Cumberland City Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- Class M soil — structural engineering included
- 1950s–1970s-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near Westmead (1 km) station

Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Why Extend Your Home in Mays Hill?
Mays Hill is a small suburb between Parramatta and Merrylands with established housing stock. Proximity to Parramatta CBD drives strong demand for quality residential construction.
Mays Hill sits in the Cumberland City local government area with 450–650m² residential blocks and R2 Low Density & R3 Medium Density zoning. Building costs are around the Sydney metro average, balancing construction value with lifestyle and growth. Transport access via Westmead (1 km) connects Mays Hill to the wider Sydney network. 1950s–1970s-era homes in Mays Hill often have good structural foundations worth building on. Extensions add living space at a fraction of the full rebuild cost. Ground conditions (Class M) across Mays Hill are well understood by local builders — Buildana's engineering accounts for moderately reactive soil movement.
Home extensions across Cumberland LGA are popular in suburbs like Greystanes, Girraween, and Wentworthville where 1970s–1990s homes have good structural foundations worth building upon. Rear living extensions, second-storey additions, and master suite upgrades are the most common projects. Cumberland Council requires DA for extensions exceeding certain thresholds. Buildana manages structural engineering, design, approvals, and fixed-price construction.
Planning Controls — Cumberland City Council
Cumberland LEP 2021 & DCP. R2 zones: FSR 0.5:1, R3 zones: FSR 0.7:1, building height 9m, front setback 6m, landscaped area 35%. Heritage items and conservation areas apply in parts of Granville and Auburn. CDC available for eligible designs.
Home extension builder in Mays Hill — key facts
- Suburb
- Mays Hill, NSW 2145
- Council / LGA
- Cumberland City Council (Cumberland City)
- Primary zoning
- R2 Low Density & R3 Medium Density
- Typical lot size
- 450–650m²
- Soil class
- Class M
- Median house price
- $1.0M–$1.3M
- Home era
- 1950s–1970s
- Typical price range
- $150,000 – $600,000+
- Typical timeline
- 6–12 months design to handover
- Approval pathway
- CDC for most rear extensions, DA for second-storey
Building in Mays Hill — Local Context
Mays Hill Block Realities
Typical Mays Hill blocks are 450–650m² on Class M ground (moderately reactive). For a extension, the structural envelope is more constrained than the headline lot size suggests — once you subtract setbacks, easements, landscaped area requirements, and any tree preservation, the actual buildable area is usually 35-45% of the block. We map that early in the feasibility stage so you're designing to what's actually allowed, not what looks possible from the title plan. Foundation cost band on most Mays Hill blocks: $15,000–$32,000.
Approval Timeline for Mays Hill
Realistic timeline for a extension in Mays Hill: 8–14 weeks for DA through Cumberland City Council. Add 2–4 weeks before lodgement for documentation, BASIX certificate, geotech report, and survey if you don't already have one. Construction Certificate is issued separately before works commence.
Realistic Budget for Mays Hill
For a home extension in Mays Hill, the budget conversation starts with what you actually want versus what the site supports. Most quotes you'll get from volume builders strip out the things that matter on Class M soil — engineered slab upgrade, decent waterproofing, real drainage design, BASIX-compliant glazing — and present them as variations after you sign. We don't do that. Buildana's contract is fixed-price including everything required to deliver a extension that complies with NCC 2025 on a 450–650m² block in Mays Hill.
Designing for the Mays Hill Streetscape
Mays Hill's housing stock is predominantly from the 1950s–1970s. Westmead (1 km) from the nearest station. The local anchor is Mays Hill shops & Parramatta Park. For a home extension, the streetscape question matters more than most builders admit — a brand-new double-storey on a street of single-storey 1950s–1970s weatherboards will draw council attention on bulk and scale, even if technically compliant. Buildana designs the front elevation to read appropriately for the street while modernising the floor plan and structure behind it. Materials palette, roof pitch, fenestration rhythm — all chosen to settle into the existing rhythm rather than fight it.
What Recent Approvals Show
Cumberland City Council's recent decisions for Extensions in Mays Hill reveal a clear pattern — applications with proper structural engineering tied to the existing footings on Class M soil and clean shadow analysis to neighbours' POS are progressing without RFIs. Sloppy lodgement adds 4-8 weeks of round-trip; clean lodgement doesn't.
Builder’s Take on Mays Hill
Existing-structure assessment is the non-negotiable first step. Mays Hill 1950s–1970s homes often have undersized footings or termite-damaged wall plates that won't carry a second storey. We check with drilled inspections before quoting — no point designing a dream that's not structurally viable.
Second storey on a Mays Hill home: the existing single-storey footings usually need reinforcement, which adds $15K–$40K. The roof comes off. The house is exposed for 4–8 weeks (weatherproofed nightly). Clients often underestimate the disruption — but the result is a doubling of floor area for 50% of the cost of a rebuild.
Mays Hill vs Nearby Suburbs
Mays Hill vs nearby suburbs — key metrics for extending.
| Suburb | Median Price | Typical Lot | Soil Class | Era | Station |
|---|---|---|---|---|---|
| Mays Hill2145this suburb | $1.0M–$1.3M | 450–650m² | Class M | 1950s–1970s | Westmead (1 km) |
| Westmead2145 | $1.1M–$1.5M | 450–650m² | Class M | 1950s–1970s | Westmead |
| Merrylands2160 | $1.0M–$1.3M | 500–700m² | Class M | 1950s–1970s | Merrylands |
| Holroyd2142 | $1.0M–$1.3M | 450–650m² | Class M | 1950s–1970s | Merrylands (1.5 km) |
Median price, soil class, and lot size shape build feasibility and final cost. Buildana assesses every site against these and other constraints during the free feasibility stage.
Want a real number for YOUR block — not a generic estimate?
Free site assessment, fixed-price contract, line-itemised quote within 48 hours. No high-pressure sales — just a real builder talking real numbers.
How It Works
From First Call to Final Key
Everything that has to be right before we touch the ground. We assess your Mays Hill home — existing structure, block size (450–650m²), R2 Low Density & R3 Medium Density zoning, setbacks, FSR, and your space requirements. You'll know what's achievable before spending on detailed design. Design phase covers the extension layout, junction with existing structure, window and door placement, and external finish to match your Mays Hill home's streetscape. Multiple design options presented.
⏱The Mays Hill construction phase. Fixed price, programmed, supervised. Documentation pack covers structural engineering for the new footings sized to match existing depths on Class M soil, BASIX 2025 compliance, shadow diagrams to neighbours' POS, hydraulic, and detailed sections through the wall-tie junction. Approval-grade, not concept-grade. Fixed-price construction of your extension. New footings engineered for Class M soil, structural connection to existing home, frame, fit-out, and finishes. Weekly updates from your project manager.
⏱The job isn't done when the site's clean; it's done when you have keys, certificates and warranties. Handover documentation covers the new work specifically — OC for the extension, structural certs, BASIX certificate updates, and warranty for the new section plus the junction detailing. Existing house remains under whatever warranty position applied before.
⏱Quality Promise
Every Buildana home extension in Mays Hill is delivered under a fixed-price contract — from design consultation through to defect-free handover.
Cost Guide
| Item | Estimated Range |
|---|---|
| Small rear extension (up to 30m²) | $93,000 – $190,000 |
| Medium rear/side extension (30–60m²) | $190,000 – $330,000 |
| Large ground-floor extension (60–100m²) | $330,000 – $520,000 |
| Second-storey addition (60–120m²) | $290,000 – $570,000 |
| Wrap-around (ground + 1st floor) | $520,000+ |
| Structural engineering & tie-in | Included |
Prices are indicative for Western Sydney (2025). Actual costs depend on site, specifications, and approvals.
Our Team
Oliver Alameri
Founder / Director / Builder · MPropDev · PhD Student
Ahmad Alameri
Accounts Manager
Claire Wendell
Project Manager
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Frequently Asked Questions
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Liverpool, NSW
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Headquartered in Western Sydney's Fairfield. Active across all 28 metropolitan Sydney LGAs — from Penrith to the Eastern Suburbs, the Hills to the Sutherland Shire.
Last updated: 1 April 2026
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Other Buildana services in Mays Hill
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Mays Hill 2145. Cumberland City Council regulations and local controls are covered on each page.