Follow us

Frequently Asked Questions

What are the benefits with container homes apart from the cool industrial vibe?

It’s probably fair enough to say that we like them just because of the way they are. In case you need more ticks on the pros side, here are a few:

  • Designed to carry heavy load through rough oceanic conditions, which
    means they are waterproof and structurally sturdy.
  • Freestanding and modular which allows more design creativity and
  • Transportable by any container trucks in case you need to relocate.
  • Off-site construction means they can get built faster and at the same
    time as site preparations to shorten building time.
What are the challenges with shipping container homes?

If you love shipping container homes, you’re probably aware of their inherent
challenges that relate to:

  • How to insulate adequately?
  • How to ventilate efficiently?
  • How to resolve the condensation problem?

These are not individual challenges but rather parts of a system that correlate to form an efficient and healthy living space. That said, condensation in container homes is still public enemy No. 1, which causes discomfort and leads to mould growth within the home if not resolved properly.

So why are containers more prone to condensation than normal homes?

Containers are built to be air and watertight, which means there are no natural means of air exchange, compared to leaks and cracks that exist in a traditional home, so any moisture within the container would potentially form condensation (also called sweating) when certain conditions are met. We all know this phenomenon with a can of cold drink on a warm day. The same thing would be happening on the container’s metal walls. Because container walls are fully welded, condensation droplets are trapped in the wall cavity, which would rot out any organic material (timber studs, plaster boards, etc.) and promote mould growth inside the home.

How do Sonic Steel address condensation?

Our unique VenSulation system comprises of two parts: For ventilation, we regulate the humidity level so there is no build-up of excess moisture, through the mean of Heat Recovery Ventilation (also called HRV); for insulation, we eliminate air gaps within the wall cavity so no moisture could come into contact with the metal surface and form condensation.

a. Because containers are more airtight than conventional homes, they need to rely on natural ventilation through windows and doors for air exchange, which also means a decrease of thermal efficiency. That is why we add mechanical ventilation to our system. We use Zehnder’s Heat Recovery Ventilation (or HRV), which can retain up to 85% of thermal energy while bringing in fresh filtered air in exchange with stagnant air. So, on a cold winter night, you can keep warm with all the windows shut, and still be able to enjoy the ventilated fresh air, all from just 8W of power. The HRV also maintains a constant humidity level inside the home by eliminating excess moisture that’s generated by cooking, washing and breathing. Having a HRV helps make your home more energy efficient as it reduces the load on your air conditioning system, and most importantly, it ensures a healthy and comfortable living space.

b. Insulating a container is trickier than a normal home, due to the limited width and the corrugated metal walls. To prevent condensation (a precursor to mould growth), moisture must NOT come into contact with the internal metal surface. To achieve this, we CNC-cut cured PUR blocks into the same profiles as the metal wall in order to fill in the corrugations, followed by flat PUR panels, usually between 35 and 70mm. As a result, the PUR acts as a vapour barrier between the container wall and the interior space, maximising thermal and sound insulation as well as eliminating air cavities. We choose PUR for its
100% vapour resistance and the superior insulating performance compared to EPS and other materials. We also offer additional insulation underneath the floor to stop the loss of warm/ cool air due to draught.

How is Sonic Steel different from other container homes?

There are three common methods to insulating container homes: batt insulation, Cool room panel (EPS) and spray foam. Although batt insulation is effective in traditional homes, they are vapour permeable and with the airtight metal walls, the trapped moisture can promote mould growth due to the lack of air circulation. Installing vapour barrier membranes could slow down this process, but excess moisture would eventually come into contact with the metal walls and form condensation in certain conditions.

EPS/ Cool room panel insulation faces the same issue as there is still air cavity within the walls. Spray foam (closed cell) is one of the best vapour barriers to avoid condensation when applied properly. However, because the foam is created by a chemical reaction, the application must ensure that the ingredients react completely, and no residue is left that could cause off-gassing. This is not a consistent process as it depends on atmospheric factors such as:

temperature, humidity and pressure, and should only be carried out by professionals. Our PUR panels are block moulded by industry specialists in a controlled environment to ensure quality and consistency. Once cured, the foams are stored for at least 30 days before cutting and installing.

How do I know whether the container transported chemicals or toxic goods before being converted into homes?

We only use single-trip containers (also called new builds), which only transport goods for the one trip from the manufacturer to us. This means that the cargos are only limited to dry and non-perishables, usually furniture, white goods, etc. so that the condition of the container remains brand new.

How can you ensure that rainwater will not leak into the roof or around the walls?

The roof of the container is designed to not hold water as it is slightly curved. All joints on the container are also fully welded so that they are watertight. People normally face problems with rusted roofs due to the use of second-hand containers that are damaged and have low points on the roof where water collects and rusts out the steel over time. We use new containers and thus eliminate the issue. Another preventative method includes applying an extra waterproofing membrane, which would be at extra cost and might not be necessary for the purpose of preventing water leakage but does provide peace of mind and extra thermal protection.

Waterproofing is one of our utmost priorities beside ventilation and insulation. All our cut-outs and framings are fully welded, and all external electrical points (if any) are covered with fully welded plates to avoid direct exposure from the rain. Our bathrooms are also waterproofed in compliance with the building code.

How can rainwater be collected?

We suggest that you have a roofover built on top of the container once on-site for rainwater collection and extra thermal protection. We can also organise this to be built at our factory, but it must not exceed the height limit for road transport.

Do you assist with finance?

We work with Great Escape Finance who specialises in Tiny Homes lending. You can find more at:

Do windows and sliding doors come with flyscreens?

All of our windows come with flyscreens. Flyscreen for sliding doors can be added for between $300 – $800.

Do you use low VOC paint for the interior?

Yes, we use Taubmans Professional Undercoat and Taubmans Endure – both are top range and low VOC from Taubmans – to ensure a superior and easy to wash finish. The Endure Interior range also protects homes against the growth of mould, mildew and bacteria with advanced anti-microbial technology.

What paint do you use for the exterior and how long would they last?

We use Marine Grade paint, which is specifically formulated for containers to withstand all weather conditions. Our supplier’s guarantee is 15 years in oceanic conditions, so it should last much longer than that being away from such harsh conditions.

How flexible can your designs be?

We custom build most of our projects to suit individual budgets and requirements. We believe in quality and uniqueness when it comes to living styles. From room sizes down to the locations of power points, we make sure that it’s designed and built to suit your lifestyle.

Can you build multiple containers joined together?

Yes, of course. It’s important to mention that with projects where multiple containers are joined together, the cost would be somewhat similar to a conventional build, sometimes even more (due to transport, assembly, engineering and extra fabrications, etc.) depending on the design and the location. However, the advantage is that they’re prefabricated and so the building time is much less. Also, if your property is in a remote area, it might be that building container homes is more affordable as finding tradies that go there might be difficult and costly, although this is not always true. If you’re fascinated about containers as much as we do, then the appeal is definitely part of the formula.

Do you deliver instate? How do transport and on-site installation work?

Absolutely. We work with transport companies that service Australia wide. There are two ways to load/unload a container home: with a side loader truck (more affordable) or with a crane (more cost). If you are within Victoria and have reasonable access for a semi-trailer, the home can be delivered by a side loader. If you are interstate, it would be more affordable to use a side loader only for loading and unloading (from a local haulage company), and to travel the long distance by a skel trailer instead. If you have limited access to the allocated spot for the home, it would be best to engage a crane to put it in place.

Can a container home be craned over an existing house?

Yes, subject to access, overhead services and a traffic management plan.

What type of footings do I need?

This would depend on the soil types. Generally, containers are designed to only need support in the corners. Extra supports will be required depending on the amount and sizes of doors and windows, and to be specified by an engineer. From experience, our container homes are normally located on 6 or 8 concrete footings/ pads. Other footing types are also available subject to the engineering design.

What sizes of container homes can you build?

We can do both custom builds (any length between 20ft and 50ft) and standard builds (20ft and 40ft). 20ft is 2.4m x 6m and 40ft is 2.4m x 12m (approximate external dimensions). We only use Hi-Cube containers, which are 2.9m high (external). We can also join multiple containers to form double- storey or wider rooms.

What are the regulations for container homes?

Unfortunately there’s no straight answer when it comes to planning regulations, as it varies between each council and state. The general rule is that any habitable structures intended for permanent occupation would require a permit, be it a caravan, container home, or home on wheels, unless you can justify that it’s an extension of an existing building and for a dependent member of the same household. This would differ from council to council, so you would need to find out on the case-by-case basis. Your best research would be to contact your local council and check with them. If you need help, just let us know and we can assist you.

What building classification are container homes categorised under?

They can be classified as either portable/ transportable dwellings, or as permanent structures (e.g., class 1A), depending on your council’s specifications and their planning scheme. For example, relocatable homes are not defined as ‘buildings’ under the NSW EP&A Act, and according to the NSW 2006 Planning Circular, they don’t require either DA/ town planning permit or building permit (subject to LEPs); but would require a Section 68.

Activity Approval instead – Approval to Install Relocatable and Flat-pack Homes Outside a Caravan Park or Manufactured Home Estate. However, some Victorian councils would define them as permanent buildings and require planning permits, except for the Surf Coast council as they’re trialling the domestic use of tiny homes. The best research would be to do your own due diligence on the council’s website or check with them directly. If you need our assistance, please let us know and we should be able to help you with the right information.

Can you assist with town planning applications?

We work with Council Approval Group who specialise in town plannings/ DAs in Victoria and NSW. You can claim a free consultation phone call here:

What types of toilets do you use?

Our builds are adaptable to any toilet type of your choice, e.g., flush, composting, cassette (caravan style), incinerating, etc.

Do you build off-grid container homes?

Absolutely. There are a range of options on toilet types, solar system and battery size, etc. Please reach out to our friendly team for a detailed discussion.

How do I connect power and plumbing?

Our homes come with pre-installed electrical work and plumbing, which is ready to be connected to the mains once on-site

What BAL rating can you build to?

We can design and build to the required BAL and comply with local council’s regulations.

What size of mattress can I fit the bedroom?

The main bedroom is 2.19m wide, the Double mattress is 1.38m x 1.88m, Queen is 1.53m x 2.03 and King is 1.83m x 2.93m. Please refer to our mattress size guide in the Resource section. Please note that these are mattress sizes only, bed sizes can vary or can be custom built to be the same size as the mattress.

What is the normal turn-around time?

Our standard 40ft models take between 6-8 weeks to build, excluding the design process. Our queue time would vary depending on the number of orders at the time.

What are your terms on the warranty?

All our container homes are covered with a 10-year structural and 2-year non- structural warranty (terms and conditions apply)

Have you had success with getting approvals from the council?

Yes. Some of our clients chose to apply for the permits and were successful. Some of the councils are: Bellingen Shire (NSW), Home Bland Shire (NSW), Wollongong City (NSW), Southern Mallee District (SA), Tumby Bay District (SA).

Get In Touch

Use the form below to drop us an email if you have any question or comments.