Home Extension Builders Sydney

Types of extensions

Most Sydney extensions fall into a few common forms.

• Rear extensions that open the kitchen and living area to the yard
• Ground floor additions for extra bedrooms, a bathroom or a home office
• Second storey extensions over all or part of the existing house
• Living area extensions with alfresco areas or covered decks attached
• Granny flats and secondary dwellings where the lot allows

Structural considerations

A ground floor extension needs footings or a slab that match the existing floor level and suit the soil. Where the back wall comes out, beams carry the existing roof and walls above.

A second storey depends on whether the existing walls and footings can take the extra load. An engineer assesses this, and some homes need new footings or steel before the upper floor can go on.

How an extension runs, start to finish

• Site visit and brief: what you want, the budget range, and what the site allows
• Design and documentation with your designer or architect, plus engineering
• Approval through complying development or a development application
• Written quote and contract with scope, allowances and exclusions
• Construction: demolition, footings, framing, roof, lock up
• Fit out and finishing, then handover

Approvals

Some single-storey extensions can be approved as complying development through a certifier, which is usually faster. Others need a development application, particularly on heritage, bushfire or flood affected land.

What affects the price

• Floor area, and whether it is ground floor or a second storey
• Structural work: beams, steel, new footings, underpinning
• Site access and slope
• Kitchens, bathrooms and wet areas included in the work
• Finishes, windows and doors
• Design, engineering and approval costs