Building Management

Container home experts. How to manage your Tiny Home


Condensation is becoming much more of a concern in recent years. New technology and improvements in the

thermal performance of buildings means today’s homes are becoming more air tight and excess humidity in the air can be

trapped inside. Windows are usually blamed for excessive condensation because they are the first place the condensation

can be seen, but what about between the walls and in the insulation? The moisture is there too. Your windows may actually

be serving as a warning sign.

What Causes Condensation?

Condensation arises because warm air can hold more moisture than cold air. For example, air at 25°C can hold about 20

grams of water per kilogram of air. This is its maximum water content so it corresponds to 100% humidity. If air in this state

is cooled to 15°C, then its maximum water content falls to about half this value and about 10 grams of water must condense

out of each kilogram of air. This will occur as a fog of liquid droplets if the air is cooled as a mass, or as condensation on a

surface if that surface provides local cooling of the air around it.

Condensation is defined as the physical process by which a gas or vapour changes into a liquid. If the temperature of an

object (e.g. grass, metal, glass) falls below what is known as the “dew point” temperature for a given relative humidity of the

surrounding air, water vapour from the atmosphere condenses into water droplets on its surface. This “dew point” varies

according to the amount of water in the atmosphere (humidity).

Condensation on windows occurs when the surface temperature of the window is low, and the interior of the room is warm

and has high relative humidity. Condensation is not caused by a problem with the window system itself but rather the level

of humidity in the room, often due to a lack of appropriate ventilation in the room or house.

The point at which condensation will occur depends on three variables;

The inside air temperature,
The relative humidity of the inside air, and
The surface temperature of the window or glass

This combination of factors is often referred to as the “Dew Point”.

At 23°C inside air temperature, and 50% relative humidity, the dew point is around 12°C.

Some humidity is necessary for comfort and health, but too much humidity can present real health problems. High humidity

promotes the growth of dust mites and fungi (mould), both of which produce compounds that are injurious to human health.

Equally so, too low humidity is not good either. Cool, dry conditions lead to dry, cracked lips and irritated nasal passages

and airborne viruses like influenza tend to spread, possibly because of their ability to survive longer in dry, cool conditions

and infiltrate those inflamed nasal passages.


Some condensation can be expected in cold weather. The
colder the outdoor temperature, the more likely you are to have condensation.

A little fog on our windows on an especially cold night does not represent a problem, and it usually goes away fairly quickly.

How Can Condensation be Managed?
Typical domestic activities such as cooking, bathing, showering, drying, high occupancy, high indoor plant concentrations,

uncontrolled moisture ingress and domestic appliances such as gas fired stoves, burners and heaters all have an effect on

relative humidity level and therefore the potential for condensation within the building.

Typical quantities of water vapour produced in the home:


  • Breathing (active)
  • Cooking
  • Showers and Baths
  • Clothes Drying (unvented)
  • Gas Heater (unflued)


  • 0.2 Per Day (per person)
  • 3.0 Per Day
  • 1.5 Per Day (per person)
  • 5.0 Per Day
  • 1.0 Per Day

A typical home may produce in excess of 20 litres of water vapour
per day

The easiest way to control condensation is to keep the relative humidity low. When there’s too much condensation on

your windows it means that humidity is too high in your home. The glass of single glazed windows are usually the coldest

surfaces in a room and may actually be serving as a warning sign to the condensation related problems. You should take

the necessary steps to reduce humidity until condensation disappears.

Bathrooms, kitchens and other areas where humidity levels are high are particularly susceptible. In order to control

condensation, consideration should be given to improving the ventilation in these areas. The best solution is to gather as

much water vapour at its source (for example in the kitchen, bathroom or laundry) and evacuate it straight outside through

the use of exhaust fans etc.

Tips for Builders
Duct gas appliances, kitchen rangehoods, clothes dryers and bathroom exhaust fans to outside air.

Hot water heaters,gas boilers, bathrooms, clothes dryers, range hoods in kitchens and any other sources of moisture vapour should be
fitted with adequate mechanical ventilation systems which should be flued to the outdoors.

Ducts leading from air conditioners, heaters and other penetrations should be enclosed completely by ceiling insulation product.
Use vapour permeable wall wraps (not punched sarking). Ensure vapour permeable and moisture control membranes
are installed in the correct locations, sequence and orientation.

Be sure to select the right materials for the intended purpose and choose reliable products from the market. For example, vapour permeable products specified by Australian
Standard (AS) – 4200.01 cannot be substituted.

Consider building in trickle ventilation where appropriate in high performing or poorly ventilated spaces.
Create air spaces and ventilate cavities where hardboard, cement sheet or other solid materials are used for external wall claddings.
Use eaves and soffit vents to vent roof voids.
Finishing items in construction such as screed laying, plastering, plasterboard jointing, and tiling should be allowed to cure for the longest possible time before the building     is occupied.
Shelter materials on-site from rain and prevent them from getting wet prior to application/installation.
Avoid the use of un-flued gas heaters .
Air conditioning units which can control both temperature and humidity are recommended. Systems that can meet
the dehumidification requirements should be preferred to avoid surface condensation.

TIps for Homeowners/ Landlords or rented accomodation

Occupants in a new building should be more cautious about condensation related problems, and provided with a  policy on Tiny Home Mnagement by the landlord, especially during the first winter after it has been built. New structures may need extra heating and ventilation compared to older ones because of the relatively high moisture level in the new materials. Use a fan in short cycles within a room when the condensation problem is excessive or use the dehumidifying setting on your air-conditioner. Over time, these materials will dry to reach a normal moisture level.

  • For instance, a new 150 mm thick concrete floor may take up to eight months to dry while a 100 mm thick slab can reach the same level of dryness in just four months.
    Open windows during and after showering and when cooking in kitchens.
  • Use bathroom exhaust fans during and after showers and baths, and ensure they are vented externally and not just into your roof cavity.
    Dry clothes in rooms that are well ventilated and warm and shut off from the rest of the building.
  • Vent clothes dryers to the outdoors where possible. You don’t want moisture being removed from clothes to get into the rest of the house.
    Alternatively keep windows and doors open during the cycle.
  • Keep lids on pans during cooking, avoid unnecessary steam production.
  • Open windows and ventilate for short periods of time in any room with condensation.
  • Airing out the kitchen, bathroom and laundry during and after use by opening a window for a few minutes is another good way to control condensation.
  • Wiping down wet surfaces (use an old towel) and keeping the windows and walls as dry as possible are some easy ways to avoid condensation problems near windows and doors.
  • Avoidable sources of water vapour in any room should be looked for and eliminated as far as possible.
  • Finally, always consider an investment in high performance, energy efficient windows that not only reduce energy costs but make homes more comfortable as well. Double glazed windows create warmer interior glass surfaces, reducing frost and condensation.
  • Placement of container homes must be above the ground for good airflow- failure to do this will create poor airflow and thus Mold issues

Condensation will tend to form less readily on double glazed windows and doors. Condensation may form on metal window
frames before it appears on the glass, however it is  likely to be noticed first on the glass of timber or uPVC framed windows and doors.

Be alert to condensation forming on the glass and frames of windows. These are usually the coldest surfaces in a room and condensation on them is an early warning of high Relative Humidity that can support dust mite infestations and mouldgrowth.

Glass with a Low-E coating on the internal surface (surface#2 for single glazing and #4 for IGUs) promote condensation more readily than uncoated glasses.
Surface condensation should always be wiped up to discourage mould growth or decay of timber frames, window
sills or architraves. Even painted timber can absorb water which is left to sit and the paint will be at risk of bubbling or flaking when the water later evaporates.

For further detailed information on condensation management, please refer to the ABCB’s Handbook on ‘Condensation in buildings’.

Disclaimer: This key message is provided as general guidance, awareness and education  for Ganny Flats4U Clients only and is being used as a guide by GRanny Flats4U. It should not beviewed as a definitive guide and should be read in conjunction with the requirements of the National Construction Code (Visit

While every effort has been made to ensure the information is accurate the Granny Flats4U expressly disclaims all and any liability to any person for anything done in
reliance on this publication. 

Granny Flat 4u Warranties

Management of  Airflow in your Tiny home, Container home, Office, Granny Flat

Warranty Claims must be supported by the following information.
Relocated homes/ Landlords renting accomodation
  • Electrical test on all connections on each site required. ( Copy and Evidence of Date of each Test to be supplied to Granny Flats4U for any warranty claims)
  • The Purchaser of Granny Flat 4u container homes or offices must provide a copy of their Tiny Home Management Policy that specifically covers Mold management as per our sites information
  • Purchaser of Granny Flat 4u Container homes/offices must provide a copy of their Tiny Home Management Policy to any and all clients who live in or rent their container homes. Evidence of communication and knowledge transfer will be required to clients.
  • Evidence that the container is raised off the ground so as to provide airflow under the container.
  • Evidence of maintenance inspectio report similar home inspections.
Purchaser who rents out their Granny Flat4u purchased home must provide evidence of proper maintenace mold policy presented to its clients based on tiny homes mold management.
Mold is a client maintenance issue.
Container  is fitted with adequate extraction fan based on max 4 people. Running 24/7
Owner or Rental
If the extraction fan is turned off  for any reason and the owner of the tiny home is not informed any warranty claim is immediately void..
Mold is created when there isnt sufficient airflow….
With no extraction fan on and no other means of airflow Mold will form.
As mold is a maintenance issue no mold warranty exists for any clients belongings,other than if it can be shown that Electrical Testing was done and Granny flats4u was informed immediatly of any faults in the fan.
All Mold issues created by turning off the most important Mold management system in the home isthe responsibility of the  purchaser and client living in any rental accommodation.
Number of people the home is designed for. The Tiny home container is designed for 1 to 4 people.
General Building/Electrical/plumbing Warranties.
  1. Granny Flats4U Global ABN 623203895 warrants the structure of its  New Build container homes for a period of 5 years from the date of handing over title and based on supply and delivery to 1 location.
  2. Granny Flats4U warrants the interior fitting/fixtures for a period of 6 months including but not limited to:
    1. Appliances
    2. Electrical fittings
    3. Plumbing fittings
    4. Taps and plumbing fixtures
    5. Drawers, cupboards, doors, windows, sliding doors.
  1. Maintenance on delivery .PLEASE NOTE; upon delivery and installation of your container, it is recommended that the purchaser is  to check all seals around welds and windows due to movement and twisting of the container during the transportation and lifting/placement process. 
    1. Evidence of this check must be saved in the form of photos and dates by the purchaser for any warranty claims.
  2. Additionally, some internal joints or tiles/grout may experience cracking due to transport, these will generally be cosmetic and simply require one of the following; no-more-gaps, silicone or grout which are all included in your kitchen drawer. 
  3. Warranty is voided if any roofing structure are fixed, welded, bolted or any other form of fixing added to the roof of the container.
  4. Warranty is voided if any obstacle is stored on the roof of the container
  5. Warranty is void if any tree branches or any foreign objects including small sticks are on the roof.
  6. Warranty is void if Exhaust has been turned off for any length of time other than to repair upon which an immediatereport is to be generated by owner should their be a break down
  7. Tiny Home Management – Client must read and understand the Tiny Home Management Policy on Mold.….supplied on this site….


  1. Relocation – Any additional relocations in the warranty time frame. 
    1. Purchaser needs to do Maintenance as per clause 3 c and D on each location within the warranty period time frame of 5 years.…We will review any issues on a case by case basis. 
    2. Purchaser must test all electrical connections including exhaust fans.
    3. If Purchaser does not test exhaust fans and electrical and provide evidence to such the all warranties are void.
    4. Any damages to the warranted parts in the warranted time frame  made during relocation will be assessed on a case by case basis. 
    5. Any product damage will be fixed or replaced at market value of goods based on age of product. Ie if the product does not have a receipt within the 12 months of the container purchase and can be shown to be new at time of container location or relocation  then the second hand price of the goods is what will be covered subject to proof of all previous clauses.

  • Site preparation and utility connections
    1. Total and full responsibility for all site installation  and utility connections and all other connections other than the supply of the container home is the responsibility of purchaser.

  • Site Installation and any other connections
    1. All installations and connections  of the container home/offices are the responsibility of the Purchaser.
    2. All intallation in accordance with building standards for tiny homes container homes and adhere to a minimum of 300mm – 600mm placement raisedd off the ground for efficient airflow management.


  1. Delivery. Your container has a quality check done before leaving the build yard.  When being delivered by truck/train and driver – any damage caused during transport is warranted under the Trucking company insurance. Road vibrations may effect the seals and joints. Please do a check over the building once it has arrived and use the kit provided.