Home Extensions Seaforth

If you’re looking for home extensions Seaforth homeowners trust, you’ve found the right team. Monstructions handles everything from initial design through to final handover, proudly serving Seaforth, Balgowlah, Manly Vale and all neighbouring suburbs across the Northern Beaches area.

10+ years experience guarantee

10 years guarantee

100% customer satisfaction

Get A Free Quote Now!

🔥 June Special! Free site inspection + council feasibility check included. Limited to 3 jobs this month. Call 1300 098 730

IS YOUR HOME READY FOR AN EXTENSION?

Monstructions specialises in home extensions Seaforth, expertly designing and building additions that suit the homes and families throughout the Northern Beaches area. We’re proud to serve homeowners throughout Seaforth, Balgowlah and Clontarf and surrounds with our licensed team managing everything from initial design through to final handover.

Fully licensed general contracting

Quality Workmanship

Over a decade of renovation experience across Sydney

Home Extensions Seaforth
Built For The Way You Live

Seaforth homes are predominantly brick and weatherboard from the 1950s through to the 1980s, sitting on generous blocks between 500 and 700 square metres. Many properties feature original layouts with smaller living areas and enclosed kitchens that don’t suit modern family life. Extending these homes makes far more sense than moving, especially given the waterside location and established community.

We’ve completed dozens of extensions across Seaforth and neighbouring suburbs like Balgowlah and Clontarf, working with families who need more space but don’t want to leave the area. Our team understands the local character and council requirements, making sure your extension fits the streetscape while maximising usable space. From ground floor rear additions to full second storey builds, we handle the lot.

Seaforth offers a rare combination of harbor and beach access within 20 minutes of the city, which keeps property values strong and competition tight. Adding a well designed extension can increase your home’s value by $200,000 or more while giving your family the extra bedrooms, living space or home office you actually need. Most of our Seaforth clients tell us they wish they’d extended years earlier instead of making do with cramped spaces.

Our Home Extension Services

Whether you need a single room addition or a full second storey, our licensed team delivers quality extensions on time and within budget.

Ground Floor Extensions

Expand your living space with a ground floor addition tailored to your block and lifestyle.

Second Storey Additions

Add a full second storey to your home and double your living space without moving.

Rear & Side Extensions

Maximise your block with a rear or side extension designed to suit your existing home.

DA & CDC Approval Managed

We handle the full council approval process so you don’t have to deal with the paperwork.

Benefits of a Home Extension

Extending your home is one of the best investments you can make as a Sydney homeowner.

Significant Property Value Increase

A well-built extension adds substantial value to your property at resale

Stay in Your Suburb

Extend instead of moving and keep the location, school zone and community you love

More Space for Your Family

Get the extra bedroom, living area or open plan space your family actually needs

Cheaper Than Buying

In most Sydney suburbs, extending costs far less than buying a larger home

Get Started with Monstructions Today!

Ready to extend your home and create the space your family needs? Contact us today for a free quote and let our home extension specialists bring your vision to life.

Our Extension Process

Initial Consultation

Free consultation to discuss your extension ideas, block constraints and budget.

Design and DA Approval

We design your extension and manage the full council approval process on your behalf.

Site Preparation

Full site preparation, structural work and foundation ready for building.

Construction

Licensed builders construct your extension to the highest standard with all trades managed.

Final Handover

Full inspection and walkthrough before handover to ensure everything is built to specification.

How Much Does a Home Extension Cost in Seaforth?

Every extension is different. Click the button below to hear back from us within 2 hours!

Why Seaforth Homeowners Choose Us For Their Extension?

As home extension specialists across Sydney, we manage everything from design and approvals through to construction and handover.

10+ Years of Extension Experience

Our team has delivered ground floor extensions, second storeys and full home additions across Sydney.

We Manage the Full Process

From DA approval to final handover, we handle every step so you don’t have to.

Trusted by Sydney Homeowners

Homeowners across Sydney trust Monstructions to deliver their extension on time and to budget.

Licensed and Fully Insured

Every extension is built by licensed professionals with full insurance and a fixed price contract.

Don't Take Our Word For It

"I contacted Monstructions to get an idea of a price for doing an extension on my home. Of course I contacted many other people but they were the only ones who came back to me and assisted in giving me an idea of the price. I was so grateful. I wouldn't hesitate in recommending this company as we couldn't be more happy with the team, thank you for your help and support."

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Amanda

Manly

"We had a plan of what we wanted with our 2nd story + granny flat addition, but also had a budget to meet..the Monstructions team worked hard to make that happen for us. With a few little hiccups along the way from weather delays, the boys kept the job moving as smoothly as possible and the team were amazing in keeping mess to a minimum. Allowing us to stay at home during the reno. 100% highly recommended!"

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Angela

Dee Why

"Fantastic! Monstructions did an amazing job on my home extension, all the boys that worked on my house were professional and polite, and their quality of work was second to none. From drawings to completion it was a breeze working with them. They were easy to work with and extremely efficient and professional. Thank you for all the hard work and effort, I will recommend you to everyone I know."

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David

Narrabeen

Products we use

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FAQS

Got a question?

How much does a home extension cost in Seaforth?

A single room addition typically starts from $80,000, while a full ground floor extension begins around $150,000. Second storey additions generally start from $250,000 depending on size and finishes. We provide a detailed, obligation free quote after assessing your property and understanding what you need.

How long does a home extension take in Seaforth?

Most extensions take between three to six months from DA approval through to final handover, depending on the scope and complexity of the work. Ground floor additions are usually quicker, while second storey builds take longer due to structural requirements. We’ll give you a realistic timeline during the quoting process and keep you updated throughout the build.

Do I need council approval for a home extension in Seaforth?

Most home extensions in Seaforth require either a Development Application or Complying Development Certificate through Northern Beaches Council. Some smaller additions under 25 square metres may qualify for exempt development, but this depends on your property and setbacks. We manage the entire approval process for you, including plans, submissions and any council queries.

Can I add a second storey to my Seaforth home?

Yes, most Seaforth homes are structurally suitable for a second storey addition, though some older homes may need foundation or frame strengthening. We conduct a thorough inspection and provide engineering assessments before starting any work. Second storey additions are popular in Seaforth because they maximise water views without sacrificing valuable yard space.

Do you service Seaforth and surrounding suburbs?

Yes we service Seaforth and all surrounding suburbs. Call 1300 098 730 to discuss your project.

Monstructions provides home extensions across Northern Beaches, including Scotland Island, Terrey Hills and all surrounding suburbs.