Second Storey Additions and Extensions

2nd Storey Additions in Sydney!

Table of Contents

We handle ALL NSW council approvals for a adding a second story to a house!

Second-storey additions will add significant value to your Sydney home and lifestyle. The possibilities are endless, from cozy bedrooms for each child to a spacious parents’ retreat to a large open-plan living and entertaining area.


Why would you consider adding a second storey?

A second story addition not only gives the family more room to expand, but it also adds value to the property. It can also increase the value of your home as well as the quality of life for anyone who lives there. Families need space to develop while still spending quality time together. A second-story extension ensures this, allowing you to enjoy your home in comfort for many years to come.

Building upstairs extension

Perhaps you have a growing family and require additional rooms or play areas in your home. Perhaps you’ve run out of storage space and can’t find a suitable location for all of your belongings. Perhaps you’ve finally paid off your mortgage and are ready to move into your much-anticipated, larger living quarters. When it’s time to upgrade your home, you’ll most likely have to start looking for a new, larger place to live.

What if, on the other hand, you didn’t have to? Moving is unlikely to appeal to you if you already enjoy your current location, which is convenient to your workplace, children’s school, and friends and family. Not to mention the inconvenience and sheer stress of packing and moving.

So, instead of expanding outward, why not consider remodelling and adding a second story?

Extensions to your home, particularly those that add a second level, are a fantastic way to increase the value of your home by increasing the space within it, as well as boost capital growth by creating potential views that enhance your living experience.

While adding a second storey to your home is more disruptive than adding same-level extensions, the benefits can be greater, both financially and in terms of your home’s experience, especially if you don’t have the land for outward extensions.

Consider adding a 2nd floor extension

If you’ve been considering adding on to your home, we should talk. Whether you’re planning a second-story addition or a ground-floor addition, we can handle all of your extension design and construction needs. We can assist you in designing a spacious new home that meets all of your requirements. With over 30 years of experience, we are a leading home extension contractor in Sydney. Our design experts will collaborate with you to create a space you’ll love, and our skilled craftsmen will turn your vision into a reality.

When you get a new 2nd floor extension, your neighbours will be green with envy!A second-floor extension can provide much-needed space. When we think of expanding, we usually think of the back or side of the house. Adding a second story to your home may be the best option.

The addition of a second storey

Adding a second storey doesn’t have to be complicated. There will always be some compromise and transition in every renovation, but as long as you have access to food, toileting, and bathing facilities, you will continue to live at home when constructing a second storey. You will read more about our method in the sections below, but a simple second storey extension consists of the following steps:

Design consultation and approval for second storey additions: This is where we collaborate closely with you to create the perfect second-story extension floor plan and finalise the design features you want to see in your house.

Working drawings and permits: To secure second storey extension permits, our specialist team will produce working drawings and coordinate with the city council. We’ll also go into the costs of adding a second storey.

Construction, testing, and completion for second storey extensions: During the construction of your second storey extension, you will have complete visibility. Before we finish, we’ll double-check that everything is up to code and looks fantastic.

The final move is for you to sit back and admire your brand new home addition. Adding a second storey to a home is simple with us. From the beginning of the design process to the end of the project, you have complete control.

How much space do you need for a second floor extension?

Can one bedroom and an ensuite bathroom cost less than three bedrooms and two bathrooms? This is a common question we get from our clients.

It will, in fact, happen.

However, adding those two extra bedrooms and one bathroom now, rather than later, will save you money. At this point in the planning process, further consideration is needed.

It would be more expensive to add a second storey than it would be to build outwards at ground level. There are the same costs involved if you add one ensuite or three bedrooms and two bathrooms. As an illustration:

  • Plumbing.
  • Electrical.
  • Structural Roofing.
  • A New Staircase Has Been Built.

Tip: It is important to plan the house addition. This is where your rough ideas turn into concrete designs with scaled sketches to help you with your renovation. Getting the plans exactly correct will take a few tries.

Builder for second story extension

The most cost-effective second storey extensions


A second storey extension, in our opinion, provides better value for money than any other home extension or addition, but there are some design considerations.

Because no concrete and often brickwork is required, the extension must be built ONLY on the existing structure. This will greatly reduce construction costs. When first-floor additions are designed with small extension areas added downstairs, the addition becomes uneconomical.

How much is it going to cost?

How much would it cost to build a second storey in Sydney?  When it comes to extending upwards, there are a few things to think about when deciding on a budget. You’ll still need to consider your goals. Do you want to change the style/modernise the appearance of the building, for example, or do you want to stick to a sympathetic renovation?

Plan on spending between $2500,000 and $350,000 on a medium to large second story addition. The quality and expense of building materials and inclusions would make a difference, and if the ground floor needs reinforcement to support the extension’s load, this may add a significant amount to the cost.

Have a backup plan in place for those unanticipated costs. 10% to 15% of the total construction expense should be budgeted. For example, you might need to do more electrical work, such as upgrading the fuse box, or you might need to do more plumbing. It’s possible that your roof gutter system will need to be redesigned as well.

Going up will still be more expensive than going down. This is due to the fact that the current house will need to be reinforced, and the building will be done at a height that will necessitate the use of scaffolding and shrink wrap to keep the construction dry.


Second-storey extensions from Renovation Builders Sydney Experts

Renovation Builders Sydney Experts has more than 40 years of experience assisting Sydney families in staying in their homes. Our robust end-to-end process provides you with the following benefits:

  1. Timely completion with the option to stay in your home if necessary
  2. Fixed rates give you full leverage over the building, and a 10-year structural guarantee means you’ll be able to enjoy your home for years to come.
  3. Referrals for financing to help you achieve your objectives faster.
  4. A Free Initial Design Consultation, to help you create the home you deserve

Where should stairs be placed on a second story additions?

A new staircase is almost always required for a second floor, either because one doesn’t exist or because the current ones aren’t code-compliant or robust enough.

Within or outside the current ground floor, the staircase may be mounted. To fit it inside, other areas must be sacrificed, such as a bedroom, corridor, or breakfast area. Putting it outside necessitates clearing space on the property and removing whatever is already there, such as a walkway, landscaping, or other structure. In any case,  making room for the stairwell can be difficult.

New ductwork for the heating, ventilation, and air-conditioning system must also be installed. Some homeowners prefer a separate system for the second floor, while others prefer a single system for the entire building. Any alternative necessitates planning prior to the start of construction

Is it worth putting on a second storey?

COVID-19 in 2021, as we all know, has had a devastating effect on all of us in every way; but, one of the few advantages of the pandemic is that the Australian Federal Government is now offering a $25,000 grant for housing construction/renovations in an effort to boost the industry and economy. As a result, now is the best time for you to proceed with the renovation/extension you’ve been considering. When, if not now, would it be? This is a once-in-a-lifetime chance.

Another advantage of a home extension is that it allows you to update your home. Clients can choose between a home extension and an in-house renovation. As a result, they’ll be able to give their home an entirely new look, as well as more living space. It’s like moving into a new home but never leaving the old one, allowing you to continue to live in the same place where you made lifelong memories with friends and family.

When do you need a building permit?

Taking on a DIY project can be extremely rewarding, but before you grab a sledgehammer and start tearing down walls, make sure you have the required permits. Delaying your project by a week or two isn’t a big compromise compared to paying a hefty fine to your city council for unlawfully carrying out construction work, or even having to fully demolish your work!

We have has put together a beginner’s guide to help you figure out when you can call in an expert and when you should construct or tear down to your heart’s content.

What is the difference between a building permit and a planning permit?

The purpose of a building permit is to insure the protection, health, and structural integrity of a structure. Private or Council Building Surveyors grant the permits after inspecting the building plans and the site to insure that the construction complies with the Australian Building Code. The permits must be posted on the property and forwarded to the local government.

Many people mix up Building Permits and Planning Permits, but they are two different things. And if you’ve jumped through all of Council’s hoops to get a Planning Permit, you’ll almost certainly need a Building Permit.

What is the deadline for obtaining a building permit?

Any renovations that alter the structure or shape of your home need a permit. Internal loadbearing walls can be demolished, and new window or door openings can be added. Many external additions need a Building Permit, depending on how large or intimidating they are (more on this later!).

Demolition work, ironically, often necessitates a permit. It’s critical to contact a Building Surveyor if you’re tearing down a shed, carport, garage, fence, or something else that’s larger than 40sqm, made of masonry, or can impact a public space.

Building permits are not needed for minor internal and external alterations. You won’t need one if you’re just replacing built-in cabinets in your kitchen or bathroom, for example. Replace doors and windows in the same way, as long as the gap remains the same size.

There are six different types of external modifications that necessitate permits.

When it comes to permits, external additions create a lot of confusion, mainly because others are excluded due to their size. To make it even more difficult, the distinctions between minor and major construction differ slightly from state to state. The criteria mentioned here are unique to Victoria; they may be similar in other states, but double-check with your local government to be sure.

In New South Wales? The NSW government has a fantastic online tool to help you find out whether specific additions include a permit.

1. Carports, sheds, and garages

You must apply for a Building Permit if your structure meets one or more of the following criteria:

2.4m high or more 10sqm in area or larger 1m or closer to your property’s boundary

A shed with a roof that adjoins the house, for example, is connected to another structure.

2. Fences 

If you want to build the following fence, you’ll need a permit:

2 metres or more
3 metres or less from the street’s edge
A pool barrier (even if it’s just a partial barrier)

3. Decks

Many DIY renovators believe that decks do not require permits, but all decks do. If your deck is higher than 800mm above ground level, you’ll want to make sure it has privacy features. We all want our neighbours to be happy!


Verandahs are classified as a building extension because they are roofed structures attached to a house. This means that regardless of size or height, you’ll need a Building Permit.


Pergolas are unroofed structures that are either stand-alone or connected to a house or other building as an architectural feature. They are not to be confused with verandahs or decks. In this case, the term “unroofed” refers to the lack of a roof over people’s heads (aside from the frame itself).

You don’t need to apply for a permit if your pergola meets all of the following requirements. Of course, because this is a complex structure, we recommend that you hire an expert to help you with the construction – but that is entirely up to you.

Height: less than 3.6m
fewer than 20 square metres
Not more than 2.5 metres in front of your house’s front walls

6.Retaining walls

A permit is required by law if your retaining wall:

1 metre or more
Other structures, such as a shed or a home extension, are connected to it.
Supporting your neighbor’s property’s soil and underlying structure

Second storey addition case study

John and Aimy had been happily living in their Sydney bungalow for some time, which was a traditional single level three bedroom character bungalow. The home, however, was beginning to show its flaws now that they had two young sons and parents from the Wales who wanted to visit and stay with their grandchildren.



The Background

John and Aimy wanted to add more bedroom space, a second living area, and a master suite for the visiting grandparents to stay in when they came to visit.

They were also concerned that the renovation project preserve the current house’s character and kerb appeal.

The Choice

An extension off the current home was not possible due to site coverage constraints, and John and Aimy didn’t want to compromise on the size of their garden either, with two rising boys having plenty of outdoor space.

By adding a second floor, the current house’s entire footprint may be used to meet the brief. Upstairs, there was a large master bedroom with walk-in closet and ensuite, as well as two large bedrooms and a family bathroom. Although two rooms were reconfigured downstairs to make way for the stairwell, a home office, and the much-desired second living area.

The house has nearly doubled in size, and it now has four bedrooms, two dining rooms, three bathrooms, and a home office.

The Obstacles

It wasn’t designed to withstand the weight of a second storey because it was a single level timber framed building, so additional bracing was needed. We chose to use as little steel as possible in the second level’s construction so that the number of point loads in the current house’s walls could be reduced as well. We also took care to choose the right form of bracing to minimise the amount of damage to the existing wall linings, resulting in lower plastering and painting costs.

The designers searched for design features that could be repeated on the exterior of the new second storey to insure it blended in with the existing building. We added traditional cedar shingles to make it appear authentic, and the wide bay window at the front of the house was a direct product of those efforts.

The construction and routeing of the plumbing pipework for the new upper-level bathrooms was difficult. The structural integrity of the framing is jeopardised if flooring joists are pulled out to make room for pipes, according to the building code. We couldn’t hang the pipes under the joists like we usually would because we were building above existing ceilings, so we had to think beyond the box to come up with a different solution.

John and Aimy are ecstatic about their newly renovated house. It now fulfils all of the requirements. Everyone has their own room while their visitors from Wales remain with them for several weeks at a time. Many friends and neighbours have also noticed that the house seems to have always had two levels, indicating that the time and effort put into getting the design just right paid off.



[bne_testimonials_list post=”3″ category=”house-extensions”]

We offer Free estimate and site inspection.

Table of Contents

About Us

At Builders Sydney Experts, we began in Sydney NSW and, from the late 1990s, had rapidly grown to become one of Australia’s leading home builders. We remain one of biggest and most prominent in the country to this day.


(02) 8080 4327

and get a free estimate

Sydney Office

Builders Sydney Experts
5 stars - based on 250 reviews
Level 1 , 169 Castlereagh St Sydney , NSW 2000
Builders Sydney Experts
Level 1 , 169 Castlereagh St
Sydney, NSW 2000
Phone: 0490842094
Call Now ButtonCALL 02 8080 4327