Ground Floor vs First Floor Extension — Cost and Design Comparison
Going out (ground floor) costs less per sqm but uses backyard space. Going up (first floor) costs more but preserves outdoor area. Buildana (Lic. 487805C) builds both across Western Sydney.
Cost Comparison
Ground floor extension (60 sqm, brick veneer): • Shell: $136,800–$147,300 • Fit-out (kitchen + bathroom): $53,750–$60,625 • Structural modifications to existing house: $5,000–$15,000 • All-in: $195,550–$222,925
First floor addition (60 sqm, brick veneer): • Shell: $205,500–$221,400 • Fit-out (2 bedrooms + bathroom): $40,000–$50,000 • Structural reinforcement: $20,000–$40,000 • Staircase: $10,000–$18,000 • Scaffolding: $8,000–$12,000 • All-in: $283,500–$341,400
60 sqm first floor costs 45–53% more than 60 sqm ground floor.
Design Considerations
Ground floor advantages: lower cost, simpler construction, can live in house during part of build, no staircase needed. Ground floor disadvantages: reduces backyard size, may affect outdoor living, limited by rear and side setbacks.
First floor advantages: preserves backyard, creates bedroom separation from living (upstairs = bedrooms, downstairs = living), views and breezes. First floor disadvantages: higher cost, more disruptive construction (roof removal required), may not suit all existing structures, needs council assessment of structural capacity.
When to Choose Each
Ground floor: you need more living/kitchen space, backyard is large enough to absorb the extension, budget is under $250,000. First floor: you need more bedrooms, backyard space is important, existing ground floor layout works well, budget supports $280,000+.
Some projects combine both — ground floor living extension + first floor bedroom addition. This creates a comprehensive transformation but at significant cost ($400,000–$520,000).
Contact Buildana for a free extension assessment.
