Additions and Extensions
Service · Additions and Extensions
Additions and Extensions
Extending or adding to your existing home creates more room for your family while adding lasting value to your property.
Ready to discuss your additions and extensions project in Sydney?
Service Overview
Additions and Extensions done properly.
Additions and extensions are the smartest way to unlock value from a home you already love. Instead of selling, moving out of the school catchment, and paying stamp duty on the next place, you get the space, layout and light you actually need — often for a fraction of the cost of buying up.
We build rear extensions, side extensions, first-floor additions, granny flats and secondary dwellings across Sydney. Our team handles structural carpentry, integration with the existing home, roof integration, fix out and the coordination required to keep an occupied home functioning while the works are happening.
Single and double storey additions
Rear and side extensions
Structural integration with existing home
Roof extensions and tie-ins
Seamless fix out between old and new
Full build management and trade coordination
Why this service matters
An extension has to feel like part of the original home, not a bolt-on. That takes structural planning, matched roof lines, correct floor-to-floor tie-ins and finish work that reads consistently across old and new.
When homeowners and builders need it
Homeowners engage us when they've outgrown their home, want a second bathroom, need a bigger kitchen and living area, are adding a home office or teenage retreat, or are creating a rentable secondary dwelling. Builders bring us in for structural carpentry on ground-up extensions.
Where this service is used
RenovationsRear extensionsSide extensionsFirst-floor additionsGranny flatsCustom homesDuplex conversions
Choosing a contractor
Common mistakes we help clients avoid.
- Underestimating structural work required to tie new roof and floor systems into old.
- Ignoring existing footings, which may not be adequate for a second storey.
- Poor matching of eaves, roof pitch and facade materials between old and new.
- Not accounting for the reality of living on-site during works.
- Skipping engineering because the extension 'looks small'.
Why experience matters
The benefits of hiring experienced carpenters.
- New structure that ties cleanly into old without cracking or movement.
- Consistent roof lines, eaves and facades between original and addition.
- Reduced disruption because sequencing is planned for occupied living.
- Better resale value because the extension reads as intentional, not tacked on.
Our Approach
How Platinum Carpentry Group completes this service.
We start with the plans and engineering, walk the existing home to identify structure, services and constraints, then plan the sequence to keep the home as functional as possible during works. Structural connections between new and existing are planned in detail, roof lines are set out to match, and fix out is coordinated so old and new joinery share the same standard.
Extensions differ from new builds because you inherit every decision the original builder made — good and bad. That means the trade needs to problem-solve on the run, working with existing structure, foundations and services rather than starting fresh from a slab.
Materials, methods and workmanship
- New floor systems tied into existing bearers or slabs
- Structural steel beams and posts to open up existing rear walls
- Roof extensions matched in pitch, tile or metal profile to existing
- Matched skirtings, architraves and doors between old and new
- Careful integration with existing plumbing, electrical and HVAC
Featured Projects
Recent additions and extensions work across Sydney.
Additions and Extensions
Second-storey addition — scaffold and roof frame
Additions and Extensions
Ground-floor rear extension tied into brick home
Additions and Extensions
Extension wrapped and weather-tight
Additions and Extensions
Street view — second-storey addition in progress
Why Choose Us
Why Choose Platinum Carpentry Group for additions and extensions.
Extension specialists
Structural tie-ins, matched roofs and consistent finishes are what we do most weeks.
One team, one point of contact
Framing, structural steel, cladding and fix out under one roof — fewer handovers, faster program.
Occupied-site experience
We know how to run a build around a working family — school runs, sleep, hot showers.
Honest about what your home can take
We'll flag footing, roof or structural limits before you spend money on plans that don't work.
Our Process
A clear, organised process from enquiry to completion.
Initial enquiry
Share plans and photos of the existing home — we do a first-pass feasibility.
Site inspection
We walk the home, check structure, services and access, and note what needs to be planned around.
Quotation
Detailed fixed-price quote broken into structural, external, fix out and finishing stages.
Planning
Program built around your occupancy, trades booked, materials scheduled and neighbours notified.
Construction
Demolition, structure, lock-up, fix out and finishing delivered in sequence.
Quality inspection
Full defect walk before hand-over — every join, door, and roof line checked.
Project completion
Clean hand-over, warranty documentation and follow-up after you've lived in the space for a few weeks.
Common Problems We Solve
Genuine issues clients bring to us — and how we solve them.
Existing footings not adequate for second storey
We identify this early with the engineer and quote underpinning honestly rather than hoping.
Roof lines that don't match
We survey the existing roof and set out the extension to match pitch, overhang and gutter line.
Cracking at the join line
Correct movement joints and structural detailing between old and new prevent hairline cracking down the track.
Living on-site chaos
Zoning the site, staging the works and clear daily communication keep the family sane.
Professional Standards
Benefits of Professional Carpentry.
A professionally built extension increases your home's floor area and value, integrates cleanly with the existing structure, and lasts as long as the original home. Compliance with the BCA, engineering, and council approvals protects your resale and insurance — a poorly built extension can actively reduce a home's value at sale.
Our team is fully licensed in NSW (Licence 295229C), insured, and delivers every project to the National Construction Code and relevant Australian Standards. Structural integrity, weatherproofing and compliance aren't extras — they're the baseline we work to on every Sydney site.
Frequently Asked Questions
Common questions about additions and extensions.
How long does a home extension take in Sydney?
A single-storey rear or side extension of around 40 to 60 square metres typically takes four to six months from site start to handover, including structural, lock-up, fix out and finishing. A first-floor addition on an existing home usually runs six to nine months because of the temporary roofing, structural upgrades and weather management involved. Custom or complex designs, heritage overlays and delays in council approval can push these out. We give you a stage-by-stage program with the quote so you know when structure, roof, lock-up and fix out are due to complete.
Do I need council approval for an extension?
In most cases, yes. Depending on your council and zoning, an extension will either be a Complying Development (fast-tracked through a private certifier) or a full DA lodged with council. Complying Development typically applies where you're within setbacks, height and floor space limits and there's no heritage overlay. First-floor additions and larger works usually go via a DA. We work regularly with local certifiers and draftspeople across Sydney and can point you towards the right team if you don't already have plans. Never start an extension without approval — councils actively pursue unapproved works and it can affect resale.
Can we live at home during the extension?
Usually, yes. Rear and side extensions can almost always be built while you stay in the house — we seal the works area from the existing home and keep kitchens and bathrooms functional. First-floor additions are trickier because the roof comes off; some families stay through with careful staging and weather management, others rent short-term during the roof-off period. We'll walk through the realistic options with you before you commit. Either way, we work to keep noise, dust and disruption to sensible windows, and we clean the site every evening.
How much does an average Sydney extension cost?
Costs vary based on size, spec and site conditions, but as a general guide a single-storey rear extension in Sydney currently runs from around $3,500 to $5,500 per square metre for a mid-to-premium finish, and a first-floor addition typically ranges higher because of structural upgrades and temporary roofing. Kitchens, bathrooms and joinery are usually costed separately. We provide a fully itemised quote so you can see exactly where the budget is going and adjust the spec to match what you want to spend. We're honest early about whether the brief and budget line up.
Client Reviews
Recent feedback from Sydney clients.
“The team delivered exceptional workmanship from framing through to the final details. Professional, clean and easy to work with.”
Matthew R.
New Home Build
“Our renovation felt organised from day one. Great communication, premium finishes and a result that exceeded expectations.”
Sophie T.
Full Renovation
“Platinum Carpentry Group brought real craftsmanship to our project. Reliable, detail-focused and clearly experienced builders.”
Daniel K.
Extension
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