How Energy Efficient are Solid Timber Homes?

With the increased focus on sustainable living in recent times, the energy efficiency of new homes has become a hot topic. A home that uses less energy has less impact on the environment and on our back pocket, which is something we’d all like to include in our new home builds.

However, the trouble is that when it comes to building an energy efficient home, the ratings and requirements used as a standard can be confusing and may not tell the full story. This is particularly true when it comes to solid timber homes—currently there is no formal way to assess their actual energy efficiency in Australia, which often means they are undervalued.

So, if you’re considering building a solid timber home but are looking for clarity around just how energy efficient they are, read on as we share some key tips that can help guide your decision.

How is energy efficiency in homes rated in Australia?

The standard national energy efficiency tools used across Australia are The Nationwide House Energy Rating Scheme (NatHERS) alongside the mandatory energy efficiency requirements set out in the National Construction Code (NCC). The trouble with the NatHERS system is that R-values are the only measure used to determine effective thermal performance—but in solid timber homes, the actual thermal performance is often higher than the steady-state R-value shows due to the ‘mass effect’.

In New Zealand, the importance of mass effect is recognised by a Building Code Clause that allows for alternative minimum R-values for solid timber construction where the thermal mass of the building must be taken into account.

What’s the difference between R-value and mass effect?

When there is a difference in temperature between inside and out, heat will conduct from the warmer side into the material, then slowly move through to the colder side. The R-value measures this resistance to heat flow in a steady state, which applies when the temperatures are constant.

However, in reality, there is often a fluctuation between temperatures both inside and out, depending on the time of day, season and climate. This will alter or even reverse the direction of heat flow, sometimes multiple times in the course of a day. Under these conditions, the shifting heat flow results in less heat transfer, giving walls made from high-heat capacity materials such as solid wood, a thermal performance which is more effective than the steady-state R-value shows. This dynamic process is referred to as the mass effect.

Another situation where mass effect comes into play is where the outside temperature changes but does not cross the indoor temperature. In this case the direction of the heat flow stays the same, and the time delay or thermal lag creates efficiency by delaying the peak heating or cooling load. While this will not affect the amount of heat flowing through the wall, the lag can save energy and reduce running costs.

A study on the energy performance of log homes backs this up, finding that although they often have lower steady-state R-values, log walls have been shown to provide equal or superior annual heating and cooling performance when compared to lightweight wood frame walls. For example, a log wall with a R-9 value performed similarly to an insulated lightweight wood frame wall in a temperate climate with values of R-13 to R-15, for both heating and cooling loads.

Which factors impact energy efficiency ratings?

Custom designed - living room
Custom designed – living room

NatHERS energy ratings take into account a wide range of factors when determining the rating, including the location, orientation, subfloor, roofing, lighting, ceiling fans, flooring and even the colour of the external walls. There is no generic ‘one size fits all approach’ and with 69 different climate zones identified by NatHERS across Australia, the results can be widely variable.

How energy efficient are YZY Kit Homes?

YZY Kit Homes are constructed with timber mass walls, which act like ‘thermal batteries’, storing heat during the day and gradually releasing it at night. This makes our cabins and granny flats an eco-friendly and energy efficient choice that will benefit you and the environment for many years to come.

LGL laminated timber, glulam
YZY Kit Homes are built with solid wood LGL timber

To achieve your desired energy efficiency, there are two options:

1) Build your cabin or granny flat with 60mm, 80mm, 95mm, 120mm or 140mm thickness LGL walls that will not require extra insulation, even in the hottest or coolest regions of Australia.
2) Have a minimum thickness of the walls required structurally, with external cladding or internal lining and extra insulation added in between. Cladding options are available that are low (or no) maintenance and some can also be fire resistant.

What are the NatHERS ratings on YZY Kit Homes?

Iceland Display Village Ourimbah 2020
Iceland 2-bedroom granny flat, Ourimbah Display Village

As discussed, there are many factors that impact how the NatHERS rating is calculated, which means the rating of your home will always be project-specific. In addition, the actual energy efficiency and comfort felt living in our cabins and granny flats will be better than the ratings reflect, owing to the mass effect of our solid timber walls.

As a guide, below you’ll find some indicative ratings on our designs when built in certain conditions and climates.

NSW climate zone 15 (Central Coast NSW):
Iceland design built with 60mm walls on concrete slab = 7 stars, with 80mm walls = 7.9 stars.
(A pass for this climate zone is approximately 5.2 stars.)

TAS climate zone 26 (Hobart)
Greenland design built with 80mm walls = 6.4 stars
(A pass for this climate zone is 6 stars.)

ACT climate zone 24
Iceland design built with 80mm walls = 6.1 stars, 95mm walls = 6.7 stars.
Greenland design built with 60mm walls with insulation added to 3 walls = 7 stars.
(A pass for this climate zone is 6 stars.)

Note: A passive house must not exceed a total combined heating plus cooling demand of up to 108 MJ/m2/year (108 MJ is equivalent to 7.3 star NatHERS design in Canberra.)

There’s more to energy efficiency than a rating

While the NatHERS ratings provide some useful insights into energy efficiency, it’s important to be aware that there are other factors that impact the actual efficiency of buildings, in particular, those built with timber mass walls.

In the future we hope for a similar building clause found in New Zealand to be introduced into Australia which recognises the difference in rating thermal efficiency in timber mass buildings. Until then, it is up to the consumer to look beyond the ratings, and for the builders to continue to educate, to be sure the energy efficient homes being built are the best they can be.

Upcoming NCC update

The NCC is updated every three years based on regulatory practices, industry research and public feedback. The next update is planned in 2022 and the Australian Building Codes Board (ABCB) will open consultation on stage 2 of National Construction Code (NCC) 2022 public comment in August 2021.

This stage of consultation seeks comment on proposed NCC amendments on energy efficiency and condensation. A consultation link will be sent to all registered NCC Online users once consultation on stage 2 has opened. We will submit our comments to the ABCB, to advocate for the energy efficiency of timber mass homes to be taken into account. Our recommendations will include the introduction of a clause that accounts for the importance of mass effect and allows for an alternative to minimum R-values for solid timber construction, similar to New Zealand’s current Building Code Clause to that effect.

$10,000 Grants Granny Flats Tasmania

$10,000 grants to build Granny Flats, Tasmania

  • The first 250 eligible applicants to build new ancillary dwellings will receive $10,000 grants.
  • Streamlined ‘no permit required’ approvals to construct ancillary dwellings, such as granny flats or self-contained studios.

On 29 June, Michael Ferguson, Minister for State Development, Construction and Housing announced the The $2.5 million Ancillary Dwellings Grant Program in now open for applications.

“To help meet the demand for rental properties, the first 250 new ancillary dwellings that are made available for long-term rental for more than two years will receive $10,000.” – Minister Jaensch said.

Contact your local council to see what’s possible in your area or contact Brian Best, our Authorised builder for Tasmania on 0438 966 533.

The Tasmanian Government is developing a broader housing policy framework that looks at the full array of housing market issues across the public and private sector to drive solutions, in line with PESRAC’s recommendations.

Although over the past year Tasmania had been building houses at a rate not seen in nearly a decade, Minister for Housing Roger Jaensch said more needs to be done.

In the media release ‘Comprehensive package to increase housing supply statewide’ Tasmanian Housing Minister Roger Jaensch said that the government will be providing a streamlined ‘no permit required’ approvals pathway for landowners to construct ancillary dwellings, such as granny flats or self-contained studios, on their existing properties.

Information source:

Check the Guidelines, eligibility criteria and to submit an application on the Department of State growth website.

Media release TAS government, 29 June 2021: Applications open for Ancillary Dwellings Grants Program

Media release: ‘Comprehensive package to increase housing supply statewide’, 16 March 2021

For current building regulations, please find more information on > Consumer building information or contact our builder in Tasmania.

Skyros 19 backyard spa retreat front view

Skyros 19: Backyard Spa Retreat

There are many different ways our backyard cabins can be enjoyed, from home gyms to home offices. While we love seeing our cabins used for any and all of these purposes, there’s something extra nice about a backyard cabin that’s built purely for leisure – just like this gorgeous little spa retreat.

Skyros 19 backyard spa retreat front view

When our clients were looking for a modern cabin to complement their spa and complete their outdoor entertaining area, the stylish Skyros 19 design was the ideal fit. The end result really looks the part, with visually appealing contrasting colours and lots of natural light inside, creating a relaxed and ambient vibe, perfect for weekends in the sun.

Skyros 19 backyard spa retreat side view

The decking is a practical and attractive addition. Easy to maintain, it provides a safe and stable base for the spa – not to mention a great place to set up a few deck chairs and a barbeque!

Inside, the cabin is spacious enough to house a couch, dining table, bar and fridge, plus other thoughtful additions to make entertaining friends and family a joy and a breeze.

Inside Skyros 19 backyard spa retreat

Not only is the cabin energy efficient thanks to the double-glazed timber windows and doors, but with walls that are constructed entirely from timber, it’s also an eco-friendly choice that will capture carbon rather than create it.

Because the cabin has a floor plan of less than 20m2 it was able to be built without council permission in NSW – which meant this fabulous new space was constructed and ready to be enjoyed sooner.

Skyros 19 backyard spa retreat floor plan

Understandably our clients love their new space and are now in the process of adding all the finishing touches to make it truly spectacular. We’re sure there is much fun and many good times ahead!

Check other YZY backyard cabins to find the best option you are looking for and visit a gallery of built cabins.

Tax benefits for Home office and CGT exemption for Granny Flats

Tax benefits: Home office and CGT exemption for Granny Flats

Australian Government has rage of tax related programs which can help you to save money as a business owner or employee working from home. Older Australians or people with disabilities are entitled for capital gains tax exemption. Check below for more detailed information.

Continue reading Tax benefits: Home office and CGT exemption for Granny Flats
Timber homes sustainable choice

Here’s Why Timber Homes are a Sustainable Choice

Sustainable Timber Homes

It’s no secret that building a new home is exciting-having full control over the design allows you to create a space that’s perfectly suited to your style and needs. It also presents you with a unique opportunity to make sustainable choices that will have a real and lasting positive impact on the environment and your health.

While eco-friendly homes were considered an alternative idea a decade ago, there is now a genuine expectation that new homes incorporate sustainable features into the design. From optimum orientation and passive design elements, to energy efficient appliances and airtightness, more and more people are looking for ways to reduce their footprint. A key area that can make a huge difference to the sustainability of your new home is in the materials-and timber is the standout choice in this regard.

Read on to find out why!

Our most renewable raw material just got better

Rhodes Display Village Ourimbah

Humans have been constructing buildings with wood since ancient times, however, over the past 100 years or so, concrete, steel and bricks have become more widely used. This has been due in part to a misconception that they are a safer and more structurally sound option, but pre-manufacturing technology and state-of-the-art CNC capabilities is disrupting this idea and putting timber back in the spotlight.

Structural timber, or mass timber is made by bonding pieces of wood together to create a strong and sustainable alternative to solid wood cut straight from the tree. Our Scandinavian kit homes are built with glued-laminated (glulam), a type of structural timber that is more stable and less prone to shrinkage than solid wood. There are also some key sustainable benefits to building with mass timber, and it’s this that has got many in the industry excited about its potential as a viable and sustainable alternative to non-renewable and synthetic materials.

Remove carbon from the atmosphere with your home

Living room Iceland Display Village Ourimbah 2020

Did you know that long-life timber homes act like carbon sinks, ‘removing’ carbon dioxide from the atmosphere? By weight, wood is mainly made up of water and carbon, and when trees are growing they use photosynthesis to bind around one tonne of carbon dioxide per cubic metre of wood while also releasing oxygen into the air. For every timber house, many tonnes of carbon can be stored, significantly reducing the amount found in the atmosphere.

To put things in perspective, here’s some interesting figures:

  • Our Madeira 2-bedroom granny flat can ‘remove’ 14.5 tonnes of carbon from the atmosphere—this equates to roughly the same amount of carbon emitted by the average motorist driving their car over 5 years.
  • Our Charmhaven Tennis Centre clubhouse can effectively capture approximately 30 tonnes of carbon, which is the equivalent of the average motorist driving their car over 10 years.

Avoid non-renewable materials that add carbon

Madeira - modern design interior

To add further context to the above figures, if we’d used alternative materials such as concrete, steel, brick or aluminium to construct the Madeira granny flat, it would have added 18 tonnes net in carbon emissions to the atmosphere. This is the equivalent of 6.45 years of car use by the average motorist. These materials add considerably more carbon emissions during manufacture than wood products, and also during transport due to their heavier weight. Another tick for wood is that any leftover timber off-cuts can be diverted from waste and repurposed, as they are in our factory, where they are used for bio-energy to power the site.

CO2 emissions caused by the manufacture of different building materials

CO2 emissions caused by the manufacture of different building materials (Source: Building Information Group RT environmental reports).

So while other commonly used building materials like steel and concrete add carbon, by building your home from timber, you’ll do no harm to the environment, but instead will contribute to removing carbon from the atmosphere. With this in mind, wood is clearly our most renewable raw material and is a smarter, more sustainable solution for buildings moving forward.

Will you choose sustainable wood?

Inside Charmhaven Tennis Clubhouse

When it comes to building your new home or granny flat, there are many design choices to make along the way. However, one of the most important decisions you will make is which materials you will choose to construct your new home. Will you opt for sustainable timber? Or choose carbon-emitting concrete, steel, brick or aluminium?

We think it’s simple. Wood is our most renewable raw material and using it to build healthier, more sustainable homes just makes sense!

If you’d like more information about our Scandinavian Kit Homes, get in touch with our team or download our Information Pack to learn about our designs, or our Builder Info Pack to find out more about joining our network of builders today!

Display Village Ourimbah 2020 3

Largest Display Village for Sydney, Central Coast and the Hunter

Do you live in Sydney, Central Coast or the Hunter Region? Welcome to our New Expanded Display Village of YZY backyard cabins and granny flats located in Ourimbah, Central Coast.

Continue reading Largest Display Village for Sydney, Central Coast and the Hunter
Meet Brian and Kate Agfest 2021

Meet the builder servicing Tasmania at Agfest

We are proud to announce that ShedBarn, a reputable local business based in George Town, has joined our builder’s network to supply and build YZY Kit Homes in Tasmania.

So, meet Brian and Kate Best, ShedBarn owners at Agfest 5 – 8 May, site S09 to discuss your project ideas building with YZY Kit Homes. 

Meet Brian and Kate Best, builder servicing Tasmania at Agfest 2021

ShedBarn has been supplying custom sheds barns, garages, farm buildings and now YZY Kit Homes will be added to their new range of products. With over three decades of experience,  ShedBarn has earned a reputation as a trusted quality Kit Shed builders. Above all ShedBarn are a team of problem solvers, and pride themselves on going above and beyond for their customers. 

ShedBarn offers:

  • Quotes and site inspections
  • Assistance with council approvals
  • Installation services available Tasmania wide

If you’d like to find out more, please get in touch with Brian Best before the show: 0438 966 533.  

Agfest event and venue information

Agfest is a multi-award-winning agricultural field days. There will be 515 fabulous Agfest exhibitors offering their special products, services and deals. Come and support Tasmania’s amazing small, medium and large-sized businesses.

The 2021 Agfest event will be in the paddock from 5 – 8 May, Wed – Sat 8am-5pm and in the cloud from 8 – 15 May.

Quercus Park
415 Oaks Road, Carrick, Tasmania 7291

Find us at ShedBarn site S09, the corner of South Street and First Avenue.

Get Google Map directions below:

More details on how to get to Agfest, where to park and plan your day at the show, please visit the Official Organizer’s website: