Home Extension Botany — Design, Approval, Structural, Build
Full-service extensions in Botany 2019: structural survey of existing 1910s–1970s home, design, Bayside Council approval, engineering, weatherproofed construction, matched finish to original dwelling.
HIA Member
MBA NSW0476 300 300Quick Answer
A home extension in Botany costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, Bayside Council approvals, and construction under one fixed-price contract.
Second-Storey & Rear Additions in Botany
A home extension in Botany rewards reading the ground and the air before the design. The Federation pockets extend character-behind and the post-war stock reads honestly, but this is reclaimed-sands country near the port, so the water table gets checked ahead of any excavation and the plan is drawn for acoustics under the flight path.
The village HCA pockets keep their frontages, remediation overlays near the port get mapped, and the era fabric gets licensed lead and asbestos handling.
At a $1.7M to $2.6M median the wing beats the friction of upsizing eastward out of the village.
We build these fixed-price, licence HBL 487805C. Get our extension scope, with the conditions mapped, before you commit.
Buildana manages the complete home extension process in Botany — 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 Botany from $150K
- Bayside Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- M — structural engineering included
- 1910s–1970s-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near Bus to Mascot (T8, 2 km) station
Reviewed by Oliver Alameri
Licensed Builder (NSW 487805C) · Master of Property Development · PhD Student · Building across Western Sydney since 2010
Read the conditions first
Botany's village stock extends well, but the site tells you how: water table on the reclaimed sands, remediation overlays near the port, acoustic design under the path.
None of it stops the work — it just belongs in the scope from day one rather than turning up as a surprise.
Ground and era handled
Where the wing touches excavation, the sands are tested and the footings engineered to suit.
Pre-war fabric gets licensed lead and asbestos removal, all of it priced in up front.
Home extension builder in Botany — key facts
- Suburb
- Botany, NSW 2019
- Council / LGA
- Bayside Council (Bayside)
- Primary zoning
- R2 Low
- Typical lot size
- 400–700m²
- Soil class
- M
- Median house price
- $1.7M–$2.6M
- Home era
- 1910s–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
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.
Cost Guide
| Item | Estimated Range |
|---|---|
| Adding a master suite (1910s–1970s Botany home) | $130,000 – $270,000 |
| Kitchen/living open-out to backyard | $150,000 – $340,000 |
| Second storey for teenagers/office | $270,000 – $530,000 |
| Extension + bathroom (growing family) | $190,000 – $390,000 |
| Full rear + roof tie-in (entertainer's zone) | $340,000 – $580,000 |
Prices are indicative for Western Sydney (2025). Actual costs depend on site, specifications, and approvals.
How It Works
From First Call to Final Key
Free consultation at your Botany home. We inspect the existing structure, check Bayside Council's controls, measure available space, and discuss what you need.
⏱Two design moves are usually on the table: match the existing house so the extension reads as original, or contrast with it so the new section is clearly modern. Both work — choice is aesthetic, and we'll show 3D renders of both before you commit.
⏱CDC (10–15 business days) or DA through Bayside Council depending on scope. Structural engineering, BASIX, and all documentation prepared and lodged.
⏱Construction phase connects new to existing — footings, frame, roof tie-in, waterproofing at junction, internal fit-out and external finish. Staged works minimise disruption to your daily routine in Botany.
⏱Final inspection focuses on the integration: paint blend, flooring transitions, ceiling height, junction waterproofing, sound transmission. The extension shouldn't feel bolted on — it should feel like the house was always meant to be this size.
⏱Our Team
Oliver Alameri
Founder / Director / Builder · MPropDev · PhD Student
Ahmad Alameri
Accounts Manager
Claire Wendell
Project Manager
Estimate Your Build Cost
Use our free calculator to get an instant cost estimate for your project
Still got questions? Talk to Oliver directly.
30-min free call — bring your block, your brief, your budget. We'll map out feasibility, timeline, and realistic cost. No sales pitch.
Frequently Asked Questions
Buildana built our granny flat in just 12 weeks. Fast approvals, great communication, and a beautiful final product. Highly recommend.
Fatima Al-Rashid
Liverpool, NSW
We Build Across Sydney
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.
Start a Botany Home Extension
Free design consultation for Botany 2019. We'll assess your home, design the extension, and provide a fixed-price quote.
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Other Buildana services in Botany
Costs, approval pathway and fixed-price contract detail for every other build type we deliver in Botany 2019. Bayside Council regulations and local controls are covered on each page.