Do you need an extra room built in your backyard? Now could be a perfect time to order your eco-friendly pool house, home office or a backyard retreat before the prices increase after Christmas. We have our classic style cabins ‘Crete Panorama 10‘ (3.8 m x 2.8 m) in stock and they are:
Available for immediate delivery
Installed in just a few days
Features double glazed windows and doors
No council approval if installed as a pool cabana (NSW)
For many, working from home has become the new normal – and we’ve learnt (sometimes the hard way!) that a quiet, comfortable, dedicated space is absolutely essential to avoid distractions and perform at your best.
You’ve likely heard the recent discussion around timber price and shipping issues which has been a growing concern for the construction industry and home builders around the world. A significant increase in demand for building products has put pressures on supply, which has led to timber prices climbing steeply.
This has been largely due to the pandemic, which has caused havoc and disrupted life and the economy worldwide. As a result, the following factors are impacting YZY Kit Homes price and supply:
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?
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.
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?
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) has opened consultation on stage 2 of National Construction Code (NCC) 2022 public comment. Responses are invited until 17 October 2021 and can be accessed here.
This stage of consultation seeks comment on proposed NCC amendments on energy efficiency and condensation. A consultation link was sent to all registered NCC Online users on 30 August 2021. 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.
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.
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.