Home Extensions in Wollongong & the Illawarra

Get a free quote

An extension gives you the room you need without leaving the street you love. We design and build home extensions across Wollongong and the Illawarra: new living areas, bedrooms, ensuites and family rooms that join your existing home as if they had always been there.

We look after the whole job, from design to council approval and build. That means one team for the plans, the approval, the engineering and the trades, from the first site visit to handover.

We are based in Dapto, and our three directors grew up in the Illawarra. We know the local homes, from post-war fibro cottages to 1970s brick houses, and the local conditions: sloping blocks, salt air near the coast and council rules that differ from one area to the next.

Get a free quote Call 0431 552 071

Extensions we build

Rear living extensions

Open up the back of the house with a new family room, kitchen or dining area that flows out to the yard.

Bedroom and ensuite wings

Add a main bedroom with an ensuite and walk-in robe, or extra bedrooms for a growing family.

Side and front additions

Where the block allows it, a side or front addition can add a room, a home office or a bigger entry.

Extend and renovate together

Rework the kitchen and living areas the extension joins, so the new space and the old one work as one.

Home renovations

Rooms over the garage

Build a guest room or studio over an existing garage, using space the house already has.

Or build up instead

If the yard is too small or too precious to build on, a second storey may suit you better.

Second-storey extensions

Our work

Our extension projects

Real photos from our own jobs, from footings to the finished room.

Port Kembla: a gabled living extension

Completed

A new living room added to the back of the house, with a raked ceiling, painted rafters, a gable of triangular windows and a full wall of sliding doors that opens onto the backyard.

White weatherboard-style extension with triangular gable windows above a wall of sliding glass doors, beside a timber deck — The finished extension from the yard: triangular gable windows over a full wall of sliding doors.

Living room with a raked ceiling, white painted rafters, a ceiling fan and a triangular high window — Inside, the raked ceiling and painted rafters make the room feel bigger than its footprint.

Corner of a living room with a sliding glass door open to a lawn and a trampoline — Sliding doors open the living room straight onto the backyard.

The same extension during construction: cladding on, door frames in place, a tradesperson carrying tools through the opening and scaffolding at the side — Mid-build: cladding on and the door frames in place.

Footings for a new extension

Under construction

Every extension starts below ground. An engineer designs the footings for the soil on your block, then the piers or slab go in before any framing starts.

Brick piers standing on new concrete footings in an excavated area beside a house — Brick piers on new footings for an extension, before the floor frame goes on.

Coledale: a guest room and dining addition

Design stage

Plans for an addition to a home in Coledale: a guest room over the garage, and a larger dining area opening off the existing living room and kitchen.

Three-dimensional concept drawing of a weatherboard house with a new addition alongside the existing home — Concept drawing of the addition alongside the existing house.

Floor plan marking a proposed guest room over the garage and a proposed dining addition beside the existing living room and kitchen — The plan: a guest room over the garage and a bigger dining area. Where an existing wall comes out, the beam is sized by the engineer.

OUR APPROACH

Our 3-Step Project Management Framework

From initial consultation to key handover — a proven process that gives you complete clarity and control at every stage.

Discovery & Design

We visit your site to understand your vision, then engage with our draughtsmen to get your plans drawn—ensuring every detail reflects what you want to build.

On-site consultation
Vision alignment
Professional plan drafting

The Specification

A second visit to review a fully broken-down specification list and your initial timeline projection. Every material, fixture, and finish—documented and transparent.

Detailed specification list
Material selections
Timeline projection

Finalization Roadmap

We finalize all adjustments to your project scope and provide an updated, transparent specifications sheet, a clear start date, and a defined timeline for your build.

Refined specifications confirmed
Start date projection
Contractual transparency

Step by step

From first visit to handover

Site visit and design

We look at the house, the block and how you live, then work with our draughtsmen on plans that suit.
Engineering and reports

A structural engineer designs the footings, beams and any steel. Depending on the block you may also need a survey, a BASIX certificate, a bushfire or flood report, or a stormwater design.
Approval

The plans are approved as a complying development certificate (CDC) or a development application (DA). More on which applies below.
Contract and insurance

You sign a written contract with the specification and start date in it. For work over $20,000 you also receive the home building insurance (HBCF) certificate before any deposit is paid.
Footings and frame

The footings or slab go in, then the floor, wall and roof frames. The certifier inspects at set stages before work is covered up.
Lock-up and joining up

Roof, windows and cladding go on. Opening into the existing house is usually left until the new part is weathertight, which keeps dust and weather out of the rooms you are living in.
Fit-out

Electrical, plumbing, insulation, linings, waterproofing, tiling, joinery and painting.
Final inspection and handover

The certifier carries out the final inspection and issues an occupation certificate, and we walk through the finished work with you.

Building an extension in the Illawarra

A few local conditions shape almost every extension we design here.

Salt air

Close to the coast, fixings, flashings, windows and cladding need to be rated for a marine environment, or they corrode early.

Reactive soils

Parts of the region sit on clay that swells and shrinks with moisture. A soil test sets the site classification, and the engineer designs the footings to suit.

Sloping blocks

Many blocks below the escarpment fall away steeply, which changes the footings, access, drainage and stormwater design.

Joining the old house

Most extensions join an older home. Roof pitch, ceiling heights, floor levels and cladding can be matched so the addition looks original, or deliberately contrasted for a modern look.

Approvals

Do I need council approval for an extension?

Yes. In NSW, any extension that adds rooms to your home needs approval. Some small decks and internal changes can be exempt, but a new room never is. Whichever route applies, an extension costing $50,000 or more also needs a BASIX certificate, which sets energy and water targets for the new work. There are two routes:

Complying development certificate (CDC)

If your block and design meet the NSW Housing Code (setbacks, a height limit of 8.5 m, floor area and landscaping rules), a council or registered certifier can approve it as complying development. Because the rules are fixed rather than assessed case by case, it is usually faster than a DA.

Development application (DA)

If the design falls outside the Housing Code, or the land has constraints such as a heritage listing, it goes to council as a DA. Council assesses it against its local planning rules, may notify your neighbours, and it usually takes longer.

Things that can affect your approval

Bushfire-prone land: a bushfire attack level (BAL) assessment sets the construction standard.
Flood-affected land: new floor levels may need to sit above the flood planning level.
Heritage items and conservation areas: usually a DA, with limits on how the addition looks.
Steep or unstable land: council may ask for a geotechnical report.
Sewer mains and easements: building over or close to them needs the water authority’s approval (Sydney Water across most of our area).

Local planning rules differ between councils, including Wollongong, Shellharbour and Kiama, so the right approval path is worked out for your block at the design stage.

Cost

What does an extension cost?

Every extension is priced from its own plans and specification, because the block, the existing house and the finishes change the number so much. These are the things that move it most:

Size and shape

The floor area, and how complex the roofline and the join to the existing roof are.

Ground conditions

Slope, soil classification, rock, and how deep the footings need to go.

Joining the existing house

Removing walls (with engineered beams), roof tie-ins and matching floor levels.

Wet areas

Kitchens, bathrooms and laundries cost more per square metre than bedrooms or living rooms, because of plumbing, waterproofing and cabinetry.

Site access

Narrow side access or a steep driveway means more handling, and sometimes a crane.

Hidden conditions

Asbestos, old wiring, rot or termite damage found when the existing walls are opened.

Finishes

Windows and doors, flooring, cabinetry, tiles and fixtures.

Approvals and reports

Certifier and council fees, engineering, BASIX, and any bushfire, flood or geotechnical reports.

You will see a fully broken-down specification list before anything is signed, so you know exactly what is included.

Book a free consultation

Peace of mind

Your protections under NSW law

A written contract

Residential building work over $5,000 (including GST) needs a written contract, and the deposit can be no more than 10% of the contract price.

Home building insurance

For work over $20,000, the builder must give you a Home Building Compensation Fund (HBCF) certificate before asking for a deposit or starting work. It protects you if the builder dies, disappears or becomes insolvent.

Statutory warranties

Building work carries a warranty of six years for major defects and two years for all other defects.

Inspections and sign-off

The certifier inspects approved work at key stages and issues an occupation certificate before the new space is used.

These come from the Home Building Act 1989 and the NSW planning laws.

What our clients say

“I found Brad to be very professional when I had any questions he would always get back to me quickly they built my extension and its magic im very happy with the end result. Also all the staff were very polite and hard working and clear up all the rubbish.”

Kathy R.

5.0 on Google

FAQs

Home extensions: common questions

Do I need council approval for a home extension?

Yes. In NSW any extension that adds rooms needs approval, either as a complying development certificate (CDC) under the Housing Code or as a development application (DA) to council. Some small decks and internal changes can be exempt, but a new room never is. Which route suits depends on your block and the design, so it is worked out early.

Can we live at home during the extension?

Usually, yes. Most of an extension is built outside the existing house, and the wall between the old and new parts is often one of the last things opened up. There may be short periods without power, water or a kitchen while services are connected, and those are planned with you in advance.

How long does a home extension take?

It depends on the size, the approval route and the weather, so there is no standard timeframe. Once the design is settled you get a timeline projection with the specification, then a confirmed start date and build timeline before you sign.

How much does a home extension cost?

Every extension is priced from its own plans and specification. The main cost drivers are the size and roofline, the ground conditions, how the extension joins the existing house, wet areas, site access and finishes. You will see a fully broken-down specification list before anything is signed.

Do you handle the plans and the council approval?

Yes. We look after it end to end, from design to council approval and build. We work with our draughtsmen on the plans and coordinate the engineer, the reports and the approval.

Will the extension match the rest of the house?

It can. Roof pitch, cladding, windows, ceiling heights and floor levels can all be matched so the addition looks original. Some homes suit a deliberately modern addition instead, and that is a design conversation to have at the start.

Can an extension suit a federation or period home?

Yes. Period homes often have high ceilings, steep roofs and decorative details, and an extension can be designed to match them so it looks original, or to contrast with them as a deliberately modern addition. If the home is heritage-listed, the extension goes to council as a development application (DA).

Can you add a bathroom or ensuite to our house?

Yes. A new bathroom or ensuite can be part of an extension, often with a main bedroom and a walk-in robe. Wet areas must be waterproofed to the Australian Standard (AS 3740) and connected to the existing plumbing, so they are planned into the design from the start.

Do you build sunrooms and patio enclosures?

Yes. We build sunrooms, including turning an existing patio into an enclosed room you can use all year. Enclosing a patio makes it part of the house, so it generally needs approval like any other extension, either a CDC or a DA. We work out which applies at the start.

Do you build glass and steel-frame extensions?

Yes. As well as timber-framed extensions, we build glass and steel-frame extensions. A structural engineer designs the steel, and the glazing is chosen to meet the BASIX energy targets where they apply.

What insurance does a builder need for an extension?

For residential building work over $20,000 in NSW, the builder must take out Home Building Compensation Fund (HBCF) cover and give you the certificate before asking for a deposit or starting work. It protects you if the builder dies, disappears or becomes insolvent.

Should we extend out or build up?

Building out on the ground is usually simpler and cheaper per square metre. Building up keeps your yard and can be the only option on a small or sloping block. Our second-storey extensions page explains how that works.

Which areas do you build extensions in?

We build across Wollongong and the wider Illawarra, Shellharbour, the Kiama region, Wollondilly and the Southern Highlands, as far south as Berry.

Other ways we can help

Where we build