Does this plan have adequate insulation for Brisbane? stumped !

Does this plan have adequate insulation for a Brisbane climate?


I don't need over kill but I fear ceilings in S5 ,in particular have insufficent insulation but also walls could be more insulated in s4 and s5.
AT what point does my dollar become less effective in terms of increased R value ratings .

Does anyone have a recommended insulation product and what $ per sq metre is that R value
With better insulation I assume my running costs and cooling effectiveness will be maximised.


Thanks in advance for any answer to any question

 

I am not sure how to make the image any bigger as I suspect the writing on the plan is too small

 

The R2.5 thermal ceiling batts that are shown are standard for Brisbane. You can increase it but as to the cost/benefit of doing so - that's probably best answered by an engineer with a full set of plans and specifications for the house.


Jeremy

 

I dont see how an engineer would help to decide what level of insulation to go to.

personally r2.5 is inadequate and I'd also strongly consider upgrading the anticon from the current entry level minimum.

if thermal performance is important, pls dont forget it starts with the design. minimise west facing openings, ensure the appropriate insulation is used for the walls etc. there also appears to be no eaves at all...

I currently live in a 2 bed apartment in a project of mine, without any solar panels my electricity usage is between $1.1.20 a day.

 

sanj,

A building services engineer is a professional whose job it is to calculate the service requirements of buildings such as acoustic insulation, thermal insulation, water and electrical services, lighting, fire safety and prevention, HVAC and mechanical conveyors (for commercial buildings).


redsquash,

Part 3.12 of Volume 2 of the BCA and AS/NZS 4859.1 set out the requirements for thermal insulation of Class 1 residential buildings. The code is too big to attach and it seems protected so I can't print to pdf the specific pages that you want but it's freely available from the ABCB website. The ceiling insulation has to be considered in conjunction with the roof insulation and the sum of the values for each have to meet the minimum requirements.

Here is the link to Volume 2: NCC 2016, Volume Two | Australian Building Codes Board


Jeremy

 

requirements are one thing and are usually the minimums, deciding how far to go above the minimum and where the best bang for buck is is what is being discussed.

I'm saying the minimum is not enough.

 

sanj,

Regardless of whether your requirements are only to satisfy the minimum specifications of the relevant planning and development authorities, to achieve a particular star rating or some other criteria that you wish to fulfill, a building services engineer is the person that can do this for you. At this point there may just be a misunderstanding over nomenclature.


Jeremy

 

there's no misunderstanding on my part.

I've completed an inner city project where all apartments got 9 star ratings, im about to complete another where they are 7 or 8 star.

I'm saying employing a building services engineer to help you decide what insulation to use on a single house is complete overkill, assuming we aren't talking a multi million dollar build.

by the time you have paid the engineer you might as well just have used the funds to upgrade the insulation anyway, instead of hearing from them that yes, the absolute minimum is in fact inadequate if you're trying to achieve a great result.

incidentally are you a BSE or have you used one?

 

sanj,

I'm not a building services engineer and I haven't used one for my projects but I've had to work with them and their and specifications on other people's projects.

I have been asked a lot of questions over the years by people who have a seemingly endless supply of money and willingness to spend it on diligence (oh to be so lucky). I, personally, would do all of the calculations myself, save the money and gain the learning experience.

Have we officially hijacked this thread?


Jeremy

 

Yes. QED

It should be adequate to refer to the CSR insulation design manual to determine what will be required

Also have a look at passive design principles

Assuming that you are mainly looking at heat gain not losses (which affect running costs in winter as well as loss of cooling)

You need to look at the whole package not just the insulation - are you using high performance glass eg: Veridian in the windows? Different glazing types will yield differing heat gains/losses.
You have not provided any shading to the windows via eaves or hoods

 

Well you may have hijacked the thread guys but in a positive way so i don't mind.

Would you like to put estimates on what would be a nice level of insulation for a north south facing house with viridian windows.please. general estimate but i believe roof minimum is R4.1

I have also requested eaves to be now included but have tentatively been told they will be 900mm . I would like bigger.
We are about 1200mm from boundary on a small lot in Brissy

 

Have you considered spray-on insulation to the underside of the roof? Also combined with ceiling batts (this reduces the transmission of heat between roofspace & below the ceiling)

Vertical shade systems on the e/w windows eg movable screens on tracks or fixed louvres aka Luxaflex won't be as invasive as super-wide eaves which, when lined may impact on window head heights.

 

No need for spray on, anticon is perfect but as I mentioned before it needs to be a higher rated one, currently it's the entry level product.

anticon does a great job of keeping a lot of the heat out to start with. without it your ceiling batts can get hot themselves and radiate heat into the property. the batts, while good for the heat will be better for keeping the heat in during winter which is why the 2 in combination are so effective.

if really on a budget and for whatever reason you can't avoid a west/fully exposed north facing window then a good window film is a reasonable option but keep in mind they don't like to use them on low e glass.

@redsquash2 maybe put the plans and other elevations up showing orientation, Windows etc?

 

There are other elements of the design to consider like the colour and type of cladding. ie. a dark coloured roof will absorb more heat than a light coloured one. Depending on it's characteristics, a thicker external wall cladding will hopefully provide less heat transmission.


Jeremy

 

Agreed. if you start with black tiled roof and exposed west facing windows you'll always be struggling to make up for it

 

Colorbond surfmist FTW

 

Had an argument with an architect once. He swore that having a black roof in a development we were finalizing would not make the property any hotter. I just couldn't understand his logic.

 

All art and no science!