Smart things about AUS & NZ ....

The Sweeper

Mellor wrote: »

The foil isn't a typical sarking, its a reflective layer. He levels of insulation used are miniscule. And very often sheets are fixed (tec-screw or otherwise) directly to rafters, if you want a reference, various school extensions built during the last 12 and next 12 months for one.

Could it be different for residential homes? I know that all new homes built have to meet a minmum five star energy requirement by law. If you don't meet the requirement through the design, orientation and situation of the house, you have to pay extra to have things changed to offset your energy consumption.

We're in our house a year, it's a timber frame, brick clad house with a tile roof (because I don't like the look of colorbond). Seeing as himself is the salesperson for the company we built with, and still sells project homes off the plans, we had a good few trips through the site on weekends to look at what's what.

The timber frames go onto a single concrete slab. The exterior of the walls are wrapped in the stuff that looks like foil, and the roof tiles are fixed right onto the timber rafters using whatever it is you fix roof tiles with. You CAN ask for an extra layer of insulation at that point, but most people don't bother, because the entire attic of the house is insulated with those yellow fibreglass insulation batons. Basically the ceiling boards are screwed onto the timber ceiling beams and the insulation lies between the ceiling beams in the attic.

Similarly the walls - the foil sheeting is on the outside of the timber walls, and then fibreglass insulation is fitted to all exterior walls, then plasterboard is screwed on, so the insulation is like the filling in a sandwich.

We got a six star energy rating when our house was assessed, because we'd opted for some extras - solar panels, 600mm eaves on the house, ceiling fans instead of cooling (we had a split system fitted nine months later, but it should eventually run off solar if we can get the solar people to ever get back here and do the installation!).

Having lived here over a year, I can tell you this place is TOASTY when the heat is on, because the insulation in the roof keeps the heat in. However, in summer it's important to not let the place heat up, because that same insulation doesn't allow the heat to escape in the evenings. We loose virtually no heat and no cool through the roof, in other words, and it makes a big difference to the habitability of the house.

My mother in law lives in one of those multi-storey weatherboard mansions with the decking all around the outside - built before the new energy regulations came in, that place is like living in a swiss cheese in terms of insulation. It's freezing in winter, and costs a fortune to heat, though in summer the exterior decking keeps it quite cool.

The Sweeper

bw wrote: »

Your lawnmower is set a little low.

/spits tea down screen.

The Sweeper

Thought of something else.

Roadwork. Digging up the road, doing the work, relaying the road, 24 hours or less. Beats staring at road cones and orange plastic netting for a fortnight.

Mellor

ugh, and a longish reply typed, boards goe down.
this one will be rushed a bit

The Sweeper wrote: »

Could it be different for residential homes? I know that all new homes built have to meet a minmum five star energy requirement by law. If you don't meet the requirement through the design, orientation and situation of the house, you have to pay extra to have things changed to offset your energy consumption.

Residential will always require greater attention due to the typical usage pattern. However; It's not difficult to meet the measures. 5 star isn't that high a standard. Don't get me wrong, its perfectly fine for Oz, but Irish standard is much higher, and rightly so.

We're in our house a year, it's a timber frame, brick clad house with a tile roof (because I don't like the look of colorbond). Seeing as himself is the salesperson for the company we built with, and still sells project homes off the plans, we had a good few trips through the site on weekends to look at what's what.

The timber frames go onto a single concrete slab. The exterior of the walls are wrapped in the stuff that looks like foil, and the roof tiles are fixed right onto the timber rafters using whatever it is you fix roof tiles with. You CAN ask for an extra layer of insulation at that point, but most people don't bother, because the entire attic of the house is insulated with those yellow fibreglass insulation batons. Basically the ceiling boards are screwed onto the timber ceiling beams and the insulation lies between the ceiling beams in the attic.

Similarly the walls - the foil sheeting is on the outside of the timber walls, and then fibreglass insulation is fitted to all exterior walls, then plasterboard is screwed on, so the insulation is like the filling in a sandwich.

This is actually pretty basic. the position of the insul doesn't matter, its the amount. Performance is proportional to thickness. Don't get me wrong, its more than enough for an australian house, as I said prevously, its easier here.

Also, I notice you didn't mention floor insulation. This is pretty standard practice in Oz, yet could never be gotten away with in Ireland. It's things like this that I refered to when I said it was easier to build here due to the climate.

Having lived here over a year, I can tell you this place is TOASTY when the heat is on, because the insulation in the roof keeps the heat in. However, in summer it's important to not let the place heat up, because that same insulation doesn't allow the heat to escape in the evenings. We loose virtually no heat and no cool through the roof, in other words, and it makes a big difference to the habitability of the house.

This is purely a climate thing. Retaining heat is never going to be an issue here. In fact, if you built to irish levels, you have serious over heating problems, and the cooling load would cause you to use more energy. Also, heat won't escape here in summer evenings, not to any sort of drastic extent, as the temp outside remains high enough not to allow significant transfer. Obviously, this is a generalization and conditions in Darwin, will differ from Tassie or snow areas.

My mother in law lives in one of those multi-storey weatherboard mansions with the decking all around the outside - built before the new energy regulations came in, that place is like living in a swiss cheese in terms of insulation. It's freezing in winter, and costs a fortune to heat, though in summer the exterior decking keeps it quite cool.

Yup, they are crap. The temp flucuates way too much. A concrete house with no insul would preform far far better as the mass regulates the heat. This is the same with tiles verses colourbond roofing.


At the end of the day, the climate here makes it far easier to build a comfortable house. The fact that you are likely to be concerned with over heating in summer proves this (its very easy to get around BTW).
My last place was concrete with no insul, and was fine all year round. The level of detail was on par with an decent irish shed.

Doc

Mellor wrote: »

Yup, they are crap. The temp flucuates way too much. A concrete house with no insul would preform far far better as the mass regulates the heat. This is the same with tiles verses colourbond roofing.

That’s fine in winter but if you have a lot of consistently hot days during the summer the concrete house will just radiate heat all night long and never cool down. The Idea of thermal mass works well in theory but unless its very well designed rarely dose in practice. Good isolation and ventilation is the key to keeping a house both cool and warm. Houses here are built for the heat not the cold you just have to take a look at the heating systems in houses (or lack there of) In my place in Melbourne there is one heater for the whole house located in the living room dose nothing to heat any of the other rooms on cold days. Irish houses are generally built to a far better standard and because they perform well in the cold.

Mellor

Doc wrote: »

That’s fine in winter but if you have a lot of consistently hot days during the summer the concrete house will just radiate heat all night long and never cool down. The Idea of thermal mass works well in theory but unless its very well designed rarely dose in practice. Good isolation and ventilation is the key to keeping a house both cool and warm. Houses here are built for the heat not the cold you just have to take a look at the heating systems in houses (or lack there of) In my place in Melbourne there is one heater for the whole house located in the living room dose nothing to heat any of the other rooms on cold days. Irish houses are generally built to a far better standard and because they perform well in the cold.

First of all, I never said that was the best option, or even a worthwhile current option, I said it was better than metal alone, without insulation and/or with poor ventilation (which was the norm in some areas for years), which would heat and cool fast to create an uncomfortable environment. If you are going to challenge somebodys post, at least makes sure actually read it.

As for thermal mass. It doesn't keep mass doesn't keep storing heat past a limit, so the number of days are largely irrelevant. Heat stored is directly related to temp. It can only store more if it gets hotter. If it had a stint of 5 record days, it would take on a lot of heat, keeping the house cooler during the day. The more takes on, the more it gives out at night, and the quicker it ditches it. So once it reaches the night, it speeds up the rate at which it loses it to regulate itself.

There are clay huts with large (500+) walls build ing the deserts that have used this to great effect for 100s of years. so, I'd take this as great example of working in practice. Or the heritage houses in sydney of stone and brick and no insul. These are doing fine today.

Also, I am well aware they build for the heat. Where did I say any different. I said this is a lot easier and simple to build for this climate.

Doc

Mellor wrote: »

I never said that was the best option, or even a worthwhile current option

no insul

I said this is a lot easier and simple to build for this climate.

Stop internet shouting at me!:P

Can I have a hug?

Mellor