Home Extension Builder Sans Souci — From $150K Fixed Price
Fixed-price home extensions in Sans Souci 2219. Rear extension $150K–$300K, second storey $300K–$500K. Bayside Council approvals managed. Free site consult.
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A home extension in Sans Souci 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.
Sans Souci Home Extensions — Fixed Price
Extension in Sans Souci is peninsula-premium — Georges River and Botany Bay 500–900m² R3 lots. Salt-grade specs. Realistic budget $450K–$1.1M for 50–110m² addition.
On the ground in Sans Souci (2219), the practical numbers shape every home extension. Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore) soil — extremely reactive clay — pushes engineered foundation work into the $45,000–$80,000 bracket on most 500–900m² blocks. R2 Low / R3 Medium (station precincts) / R4 (Wolli Creek, Mascot, Rockdale, Kogarah, Arncliffe high-rise) zoning under Bayside Council sets the building envelope, with R3 Medium Density pockets that open up dual occupancy options on qualifying lots. Median sale price across Sans Souci sits at $2.0M–$4.0M (waterfront $3M–$6M+), which frames the build-versus-buy decision from the start. Nearest rail is Bus to Kogarah (T4, 5 km), and that proximity affects everything from rental demand to construction site access.
Buildana manages the complete home extension process in Sans Souci — 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 Sans Souci from $150K
- Bayside Council DA and CDC approvals managed
- Ground floor, rear and second-storey additions
- Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore) soil — structural engineering included
- 1930s–1970s-era homes assessed for extension suitability
- Connect new to existing — clean, matched finish
- 6-year structural warranty
- Free design consultation — near Bus to Kogarah (T4, 5 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 Sans Souci?
Sans Souci is the peninsula suburb between the Georges River and Botany Bay — inter-war heritage, post-war brick and contemporary on 500–900m² blocks. Direct waterfront premium on the Georges River and Botany Bay. Botany Sands and Wianamatta Shale interface. R3 along Rocky Point Road. Coastal salt-grade specs. Premium peninsula.
Sans Souci's established streetscape and median house prices of $2.0M–$4.0M (waterfront $3M–$6M+) reflect a premium location within Bayside. Building costs sit above the metro average, offset by stronger capital growth and rental returns. Transport access via Bus to Kogarah (T4, 5 km) connects Sans Souci to the wider Sydney network. 1930s–1970s-era homes in Sans Souci often have good structural foundations worth building on. Extensions add living space at a fraction of the full rebuild cost. Soil conditions in Sans Souci (Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore), extremely reactive) are factored into every Buildana foundation design.
Extension in Bayside is mid-tier scope across the post-war fibro/brick stock dominating the LGA — inter-war heritage and Federation cottage extensions on Bexley, Bardwell Valley, Carlton, Botany village, Mascot pockets where Council expects original detail retained. Beachfront extensions on Brighton-Le-Sands, Monterey, Ramsgate Beach, Sandringham, Sans Souci require coastal salt-grade specifications and sometimes Foreshore Building Line consent. Botany Sands soil on the eastern half (Mascot, Botany, Eastlakes, Brighton-Le-Sands, Kyeemagh, Wolli Creek) drives suspended slab tie-ins, Class P/E footing engineering, and dewatering on second-storey/footing-strengthening work — specification overhead $25K–$60K above standard. Wianamatta Shale soil inland with minimal rock excavation. ANIP flight-path overlays mandate sound-rated glazing and insulation on Mascot, Eastlakes, Kyeemagh, Banksia, Wolli Creek, Brighton-Le-Sands, Botany, parts of Arncliffe. Apartment renovations dominant on Wolli Creek, Mascot, Rockdale, Kogarah, Arncliffe high-rise stock — strata bylaws and common-property approval restrict scope. Realistic budget $230K–$580K for thoughtful 50–110m² addition inland; $400K–$950K beachfront with salt-grade specs; $130K–$400K apartment-scale.
Planning Controls — Bayside Council
Bayside LEP 2021 (consolidating the legacy Botany Bay and Rockdale LEPs) & Bayside DCP. R2 Low Density covers most older streets: FSR 0.5–0.55:1, building height 8.5–9m, front setback 4.5–6m, landscaped area 35–45%. R3 Medium Density along Princes Highway, Forest Road, Rocky Point Road, The Grand Parade and around station precincts (Rockdale, Kogarah, Carlton, Bexley North, Banksia, Arncliffe, Mascot, Kingsgrove) permits FSR up to 0.9:1. R4 High Density and B4 Mixed Use concentrated on Wolli Creek (master-planned apartment precinct), Mascot, Rockdale town centre, Kogarah St George Hospital precinct, Arncliffe, Eastgardens around Westfield, and station-precinct overlays. Bayside DCP enforces 600m² R2 dual-occupancy minimum. Heritage Conservation Areas in pockets covering Botany village, Bexley Federation streets, Rockdale heritage core, Mascot inter-war pockets and parts of Kogarah/Carlton. Tree Preservation Order LGA-wide. Wianamatta Shale soil predominant inland; Botany Sands soil with elevated water table on the eastern half of the LGA (Mascot, Botany, Eastlakes, Eastgardens, Brighton-Le-Sands, Kyeemagh, Wolli Creek) requiring suspended slabs, Class P/E footings, and dewatering on basement excavations. Coastal salt-grade specifications mandatory across all Botany Bay foreshore builds (Brighton-Le-Sands, Monterey, Ramsgate Beach, Dolls Point, Sandringham, Sans Souci). Cooks River and Botany Bay foreshore riparian setbacks 10–40m. Foreshore Building Line restrictions on direct waterfront. Industrial-legacy contamination management protocols apply to remediated parcels in Mascot, Botany, Wolli Creek, Eastlakes (former industrial, brick pits, light industry, Port Botany adjacency). Aircraft Noise Insulation Project (ANIP) overlays are LGA-defining — the Sydney Airport flight path runs directly over Mascot, Kyeemagh, Wolli Creek, Arncliffe, Banksia, Brighton-Le-Sands, Botany, Eastlakes and parts of Tempe; ANIP-covered properties mandate sound-rated glazing, mechanical ventilation and insulation upgrades. WestConnex/M8 corridor through Arncliffe, Wolli Creek and Tempe defines the northern transport spine. Aboriginal cultural heritage protocols apply on parts of the Botany Bay and Cooks River foreshore (La Perouse, Kurnell adjacency).
Home extension builder in Sans Souci — key facts
- Suburb
- Sans Souci, NSW 2219
- Council / LGA
- Bayside Council (Bayside)
- Primary zoning
- R2 Low / R3 Medium (station precincts) / R4 (Wolli Creek, Mascot, Rockdale, Kogarah, Arncliffe high-rise)
- Typical lot size
- 500–900m²
- Soil class
- Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore)
- Median house price
- $2.0M–$4.0M (waterfront $3M–$6M+)
- Home era
- 1930s–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 Sans Souci — Local Context
Ground Conditions That Affect Your Build
Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore) is the rule across Sans Souci — extremely reactive clay. For your home extension, expect engineered footings in the $45,000–$80,000 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. Sans Souci is close to Bus to Kogarah (T4, 5 km) station — site access on tighter blocks adds a logistics premium, which is why we cost cranage and material delivery before signing, not after.
Bayside Planning Context
Bayside has its own LEP and DCP layered over State planning controls. For extending in Sans Souci, the practical impact: Bayside Council's DCP sets local rules for streetscape character, materials palette in some precincts, vehicle crossover widths, and tree retention. R2 Low / R3 Medium (station precincts) / R4 (Wolli Creek, Mascot, Rockdale, Kogarah, Arncliffe high-rise) zoning on most Sans Souci 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 Sans Souci
Sans Souci's median house price sits at $2.0M–$4.0M (waterfront $3M–$6M+). That's the number that decides whether a home extension stacks up financially. If you're spending more than 50% of $2.0M–$4.0M (waterfront $3M–$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.
What Makes a Extension Work in Sans Souci
Sans Souci (2219) is part of Bayside. Bus to Kogarah (T4, 5 km) from the nearest station. Building well here means understanding what the suburb actually rewards — and what it punishes. Reward: thoughtful orientation, family-scale outdoor entertaining, durable materials that look right against the 1930s–1970s streetscape, and floor plans that handle multi-generational living without feeling cramped. Punish: over-glazing on west elevations (summer heat is brutal), thin slab specs on Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore) ground, generic project-home elevations that ignore the street rhythm. Buildana has built across Bayside long enough to know where the line sits.
Building Activity in Sans Souci Right Now
Sans Souci is seeing steady residential activity — extensions are picking up as families choose to upsize their existing home rather than face stamp duty on a move. Buildana sits inside that pipeline — we know what's getting approved, what's stalling, and why.
Builder's Take on Sans Souci
Second storey on a Sans Souci 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.
BASIX re-certification on extensions catches people out. Any extension over 50m² triggers BASIX on the combined envelope. Your existing home might be well short of 7-star, so the extension has to pull the whole house closer to compliance. That can mean insulation upgrades in the existing walls and ceiling.
Sans Souci vs Nearby Suburbs
Sans Souci vs nearby suburbs — key metrics for extending.
| Suburb | Median Price | Typical Lot | Soil Class | Era | Station |
|---|---|---|---|---|---|
| Sans Souci2219this suburb | $2.0M–$4.0M (waterfront $3M–$6M+) | 500–900m² | Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore) | 1930s–1970s | Bus to Kogarah (T4, 5 km) |
| Sandringham2219 | $2.2M–$4.0M (beachfront $3M–$6M+) | 500–900m² | Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore) | 1930s–1970s | Bus to Kogarah (T4, 5 km) |
| Dolls Point2219 | $2.0M–$3.5M (beachfront $3M–$5M+) | 500–800m² | Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore) | 1930s–1970s | Bus to Kogarah (T4, 4 km) |
| Ramsgate2217 | $1.7M–$2.5M | 450–700m² | Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore) | 1930s–1970s | Rockdale (T4, 3 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.
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How It Works
From First Call to Final Key
Extension feasibility comes down to two things: what the existing structure can carry, and what Bayside Council will let you build. We assess both at the consultation — no point designing for a second storey if the slab can't take the load.
⏱Extension designed to integrate with your existing Sans Souci home — matching roof lines, materials, and flow between old and new sections. Floor plans, elevations, and 3D renders.
⏱All approval documentation prepared: structural drawings, BASIX, shadow analysis, stormwater, and statement of environmental effects (if DA). Lodged and managed through to Construction Certificate.
⏱Extension construction takes 3–6 months on average. Footings excavated and poured to match existing depth on Class M (Wianamatta Shale + Botany Sands) / Class P/E (alluvial near Cooks River + Botany Bay foreshore) soil, frame stand, roof tie-in (most weather-critical phase), lock-up, then internal fit-out at the same standard as the existing house.
⏱Defect-free inspection, OC issued, 6-year warranty on all new work. Junction between old and new sections waterproofed and warranted. Maintenance guide covers care of new and existing areas.
⏱Quality Promise
Buildana's Sans Souci home extension process: assess the existing structure, design the addition, approve, build. Fixed price throughout.
Cost Guide
| Item | Estimated Range |
|---|---|
| Single-room addition (bedroom/study) | $63,000 – $150,000 |
| Kitchen/living extension | $160,000 – $370,000 |
| Master suite + ensuite addition | $140,000 – $290,000 |
| Second storey (full or partial) | $290,000 – $580,000 |
| Multi-room ground floor wrap | $370,000 – $630,000 |
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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Last updated: 1 April 2026
Extend, Don't Move — Sans Souci
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