Home Extension Builder Wahroonga — From $150K Fixed Price
Fixed-price home extensions in Wahroonga 2076. Rear extension $150K–$300K, second storey $300K–$500K. Ku-ring-gai Council approvals managed. Free site consult.
HIA Member
MBA NSW0476 300 300Quick Answer
A home extension in Wahroonga costs $150,000–$600,000+. Rear extension from $150K, second-storey addition from $300K. Buildana manages design, Ku-ring-gai Council approvals, and construction under one fixed-price contract.
Wahroonga Home Extensions & Additions
Extensions in Wahroonga split heavily — heritage Federation homes east of Pacific Hwy need carefully composed second-storey or wing additions through full DA, while post-war west-side homes take simpler rear extensions. Hospital precinct zoning checks on the western edge. Hornsby boundary north. Realistic budget $400K–$800K including pre-construction heritage work where applicable.
Wahroonga's housing stock is mostly from the 1920s–1960s (heavy heritage stock), which is the era where structural bones either hold up or don't — and we see plenty of both across the suburb. For extending here, that history matters: asbestos survey before any demolition is non-negotiable, and licensed removal lands somewhere between $5,000 and $25,000 depending on what's actually there. Median price $3.0M–$4.6M on typical 800–1,500m² blocks. Class M ground, foundation cost band $15,000–$32,000.
Buildana manages the complete home extension process in Wahroonga — 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 Wahroonga from $150K
- Ku-ring-gai Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- Class M soil — structural engineering included
- 1920s–1960s (heavy heritage stock)-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near Wahroonga 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 Wahroonga?
Wahroonga is premium upper north shore — Knox Grammar, Sydney Adventist Hospital (the San), and Wahroonga Park frame the suburb. Blocks 800–1,500m², heritage Federation streetscapes east of the Pacific Highway, and one of the strongest school catchments in Sydney. The hospital precinct adds zoning complexity on the western edge. Wahroonga station puts the city around 32 minutes away. The northern boundary runs into Hornsby Shire at Waitara.
Wahroonga's established streetscape and median house prices of $3.0M–$4.6M reflect a premium location within Ku-ring-gai. Building costs sit above the metro average, offset by stronger capital growth and rental returns. Wahroonga benefits from Wahroonga station on the doorstep — walkable rail access lifts both rental demand and property values. 1920s–1960s (heavy heritage stock)-era homes in Wahroonga often have good structural foundations worth building on. Extensions add living space at a fraction of the full rebuild cost. Soil conditions in Wahroonga (Class M, moderately reactive) are factored into every Buildana foundation design.
Home extensions across Ku-ring-gai mostly target the post-war and 1960s–1970s stock that sits between the Federation heritage homes — those mid-century houses often have small kitchens, closed-off living, and no connection to backyards that average 400m² of lawn. Rear ground-floor extensions for kitchen-living-dining and outdoor flow are the most common scope. Second-storey additions on heritage Federation homes need careful design to satisfy Council's character controls — pitched roof forms, articulated dormers, and matched eave detailing. Tree Preservation Order applies to any tree close to the work zone. Realistic budget: $250K–$650K for a 60–120m² addition on a typical Ku-ring-gai block, plus $40K–$80K of council/heritage/structural pre-construction.
Planning Controls — Ku-ring-gai Council
Ku-ring-gai LEP 2015 & Ku-ring-gai DCP. R2 Low Density: FSR 0.3:1 on lots under 1,200m² (sliding down to ~0.27:1 on larger lots), building height 9.5m, front setback 9–12m varying by streetscape, landscaped area 50%, deep soil 30%. Heritage Conservation Areas cover significant portions of Gordon, Killara, Pymble, Wahroonga, Warrawee, Roseville and Turramurra — heritage character assessment is required before any DA. Tree Preservation Order is one of Sydney's strictest: any tree over 5m high or 0.45m trunk circumference needs Council consent before removal. Bushfire planning (Planning for Bushfire Protection 2019) applies in St Ives, St Ives Chase, North Turramurra, North Wahroonga and bush-edge lots — BAL assessment is mandatory. The 2024 NSW TOD reforms permit medium density inside 400m of Roseville, Lindfield, Killara, Gordon, Pymble, Turramurra and Warrawee stations, but Council scrutiny on built form and tree retention remains heavy.
Home extension builder in Wahroonga — key facts
- Suburb
- Wahroonga, NSW 2076
- Council / LGA
- Ku-ring-gai Council (Ku-ring-gai)
- Primary zoning
- R2 Low Density
- Typical lot size
- 800–1,500m²
- Soil class
- Class M
- Median house price
- $3.0M–$4.6M
- Home era
- 1920s–1960s (heavy heritage stock)
- 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 Wahroonga — Local Context
Ground Conditions That Affect Your Build
Class M is the rule across Wahroonga — moderately reactive. For your home extension, expect engineered footings in the $15,000–$32,000 range. The variables that shift you up or down inside that band: building footprint, number of storeys, point loads (heavy stone benchtops, masonry feature walls), and whether the adjacent stormwater system needs upgrading. site access on tighter blocks adds a logistics premium, which is why we cost cranage and material delivery before signing, not after.
Ku-ring-gai Planning Context
Ku-ring-gai has its own LEP and DCP layered over State planning controls. For extending in Wahroonga, the practical impact: Ku-ring-gai Council's DCP sets local rules for streetscape character, materials palette in some precincts, vehicle crossover widths, and tree retention. R2 Low Density zoning on most Wahroonga blocks permits single dwellings, alterations, and additions. Buildana checks every overlay (heritage, bushfire, flood, acid sulfate soil, biodiversity) before quoting.
What a Extension Costs in Wahroonga
Wahroonga's median house price sits at $3.0M–$4.6M. That's the number that decides whether a home extension stacks up financially. If you're spending more than 50% of $3.0M–$4.6M on a extension, the economics tilt toward knockdown rebuild instead. Worth running the numbers properly before locking in scope. Buildana provides itemised quotes — no provisional sums, no allowances, no "as per engineering" line items.
Lifestyle Fit in Wahroonga
Wahroonga has a settled residential character.. Local landmark: Knox Grammar & Sydney Adventist Hospital (San). For families extending here, the design considerations that matter day-to-day: orientation for natural light (north-facing living wherever the lot allows), separation between adult and kids' zones, a kitchen that opens to outdoor entertaining, garage size that fits a real family vehicle plus storage, and a layout that doesn't require renovating again in 10 years as the kids grow. Buildana designs for the long arc of how families actually use a home, not just the showroom photo.
Ku-ring-gai Council Processing & Wahroonga Activity
Ku-ring-gai Council processes thousands of residential applications a year across the Ku-ring-gai LGA, and Wahroonga (2076) sits in the active end of that workload. For a home extension, the realistic clock from lodgement to DA determination is 8-14 weeks. The applications that move to the front of the queue are the ones where every required document is correctly named, drawn to scale, and matched against the SEPP or LEP clause it's claiming compliance with. Buildana lodges every project at that standard — not because it's required, but because it's how you avoid sitting in the RFI loop for an extra month.
Builder's Take on Wahroonga
Existing-structure assessment is the non-negotiable first step. Wahroonga 1920s–1960s (heavy heritage stock) 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 Wahroonga 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.
Wahroonga vs Nearby Suburbs
Wahroonga vs nearby suburbs — key metrics for extending.
| Suburb | Median Price | Typical Lot | Soil Class | Era | Station |
|---|---|---|---|---|---|
| Wahroonga2076this suburb | $3.0M–$4.6M | 800–1,500m² | Class M | 1920s–1960s (heavy heritage stock) | Wahroonga |
| Warrawee2074 | $3.2M–$4.6M | 900–1,500m² | Class M | 1920s–1960s (heavy heritage stock) | Warrawee |
| North Wahroonga2076 | $2.4M–$3.4M | 1,000–2,000m² | Class M | 1950s–1970s | Wahroonga (2 km) |
| Turramurra2074 | $2.8M–$4.2M | 700–1,100m² | Class M | 1920s–1960s (heavy heritage stock) | Turramurra |
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.
Have a question about your project?
Talk to our team — free site assessment and fixed-price quote.
How It Works
From First Call to Final Key
Everything that has to be right before we touch the ground. Walk through your Wahroonga home with our designer and structural engineer. We measure, photograph, and check the bones — footings, frame condition, roof structure. The cost estimate that follows is grounded in what we found, not a generic per-m² number. Our designer works with your existing home's layout — connecting new living areas to existing rooms, matching materials and roof pitch, and maximising natural light. You approve floor plans and 3D renders before we proceed.
⏱The Wahroonga construction phase. Fixed price, programmed, supervised. Most rear extensions in Wahroonga qualify for CDC — cleaner, faster, no neighbour notification. Second-storey additions typically need DA through Ku-ring-gai Council because of overshadowing and privacy assessments. We choose based on your design, not on what's easier to lodge. Extension built from new footings to completion — connecting structurally to your existing home. Class M soil design managed. Temporary weatherproofing maintains liveability where possible.
⏱The job isn't done when the site's clean; it's done when you have keys, certificates and warranties. Walk through the completed extension, confirm finishes, collect your OC. Six-year structural warranty covers all new work including the junction with your existing home. Maintenance guide provided.
⏱Quality Promise
Our Wahroonga home extensions connect old-to-new cleanly. Matched brickwork, tied roofline, no awkward transitions.
Cost Guide
| Item | Estimated Range |
|---|---|
| Small rear extension (up to 30m²) | $119,000 – $240,000 |
| Medium rear/side extension (30–60m²) | $240,000 – $420,000 |
| Large ground-floor extension (60–100m²) | $420,000 – $660,000 |
| Second-storey addition (60–120m²) | $370,000 – $730,000 |
| Wrap-around (ground + 1st floor) | $660,000+ |
| 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
Estimate Your Build Cost
Use our free calculator to get an instant cost estimate for your project
Ready to take the next step?
Free consultation — no obligation, no pressure.
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
Buildana builds across greater Sydney — with deep roots in Western Sydney's Fairfield, Liverpool, Cumberland, Canterbury-Bankstown, and Blacktown LGAs.
Last updated: 1 April 2026
Wahroonga Extension — Free Consultation
Free design consultation for Wahroonga 2076. We'll assess your home, design the extension, and provide a fixed-price quote.
Start Your Project