Retrofit vs new window frames

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arnies

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#262238 11-Jan-2020 21:21

I currently have timber single glazed windows in my home which we are considering double glazing over the next few years.

I have a quote to retrofit the timber frames, but I'm wondering if its worth getting replacement frame quotes too?

I've seen PVC frames become more popular recently. Does anyone know how they do acoustically? One of the main reasons we'd like to DG is to minimise street noise, so i'm worried the PVC frames might not do well compared to Timber or Aluminium.

How much more does re-framing approx cost vs retrofitting?

timmmay

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#2390450 11-Jan-2020 21:37

We had PVC retrofit into existing frames, with a couple of new frames too. When I went from old inch thick wooden windows, which had a pane of glass and a pane of 3mm thick plastic, to PVC retrofit into existing frames, the noise levels went up. We could hear the heat pumps outdoor units much more clearly, and a bit more vehicle noise.

The double glazed glass units sit on spacers, so the only thing preventing noise coming in is two thin pieces of plastic. I'm not sure aluminium would do much better.

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mattwnz

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#2390466 12-Jan-2020 00:51

I find aluminum frame don't really transfer sound. You certainly notice a big difference when the windows is opened a crack. It isn't something you really think about. Timber windows are generally a good type of window frame if you can get them double galzed, as long as there isn't any rot. To gtet new timber frame windows built is incredibly expensive. I have made some in the past and they are quite labour intensive.

Jase2985

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#2390472 12-Jan-2020 08:47

timmmay:

We had PVC retrofit into existing frames, with a couple of new frames too. When I went from old inch thick wooden windows, which had a pane of glass and a pane of 3mm thick plastic, to PVC retrofit into existing frames, the noise levels went up. We could hear the heat pumps outdoor units much more clearly, and a bit more vehicle noise.

The double glazed glass units sit on spacers, so the only thing preventing noise coming in is two thin pieces of plastic. I'm not sure aluminium would do much better.

your experience is not the norm as you had that 3mm layer of plastic in there

Im not sure what you mean by the bottom comment either. im pretty sure all glazing (sans wooden frames) sits on spacers.

timmmay

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#2390584 12-Jan-2020 13:51

Could be all double glazed units sit on spacers. That means the only thing keeping noise out of that part is the frame. Two thin pieces of PVC don't keep all that much noise out I guess.

Stu1

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#2390594 12-Jan-2020 14:42

I would definitely recommend getting quotes, it also depends on the current state of them a lot of ours are actually twisted so need full replacements. We did kitchen one last year with gas and tint amazing difference with warmth ,sound and no condensation. Saving for rest of house this year or next. The cost if windows is not too bad more you buy cheaper it is , however install costs are very high we got quotes 2k for one 1800 x 1.2 window . Lucky we gad a friend put it in for us

timmmay

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#2390597 12-Jan-2020 14:57

Note that most window and door places are super busy, and the wait time can be 1-12 weeks to get a quote then average of 2-5 months to get them fitted after that.

mattwnz

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#2390600 12-Jan-2020 15:08

timmmay:

Note that most window and door places are super busy, and the wait time can be 1-12 weeks to get a quote then average of 2-5 months to get them fitted after that.

It shouldn't be any worse than quotes for most building type products. But there aren't a huge number of supplier of windows in NZ, just lots of brands, but many brands are the same product. I guess it depends on how much some of them want the job. Some companies are better than others. Build wuality can be an issue I have found, and sometimes they have to come back multiple times to get it right.

I would also look at the cross section details of the windows, especially how they drain water, and where there are thermal breaks, as well if the design is likely to let in noise if any.

SATTV

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#2390601 12-Jan-2020 15:12

We went from wooden frame, single glass to uPVC with Double glazing from Homerite, we fully replaced 11 windows, 3 doors and did two inserts.

The noise level difference is chalk and cheese, ours were installed early march ( a few years ago ) and the first night the crickets were going for it, close the window and could not hear them, open the window and crickets were loud.

We have got used to the noise however, we still can hear road noise but it is a lot quieter.

Some of our frames were rotten and the two so it made sence to replace the lot, two frames were not practical to replace.

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Hammerer

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#2390644 12-Jan-2020 15:32

Noise is generally reduced by frames with more mass. So aluminium frames transfer less noise than PVC frames. We've had this discussion in other topics here.

bfginger

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#2392250 14-Jan-2020 23:37

There are exceptions but the quality or condition of New Zealand wooden window frames from the 20th century is often quite poor which is something to take into account before putting money into them. The cost of retrofitting varies widely but don't expect too much relationship between quoted price and competency. Installing all new joinery should be more expensive.

For best thermal performance ask for Metroglass XCel low e glass or a competitor's equivalent like Lightbridge or Solace. I'm going to guess the industry favours narrower air gaps in retrofits which would reduce thermal performance.

If your windows are typical wooden windows with no seals, the lack of seals will be the biggest factor in letting sound through. Competent retrofitting of seals will reduce noise. It doesn't matter how good the frame and double glazing is, a lack of seals is like an open window for sound. People excessively associate double glazing with sound reduction when the major difference they've experienced has been the installation of a frame with seals.

Aluminium with a thermal break is your best easy bet for acoustics among window frame materials (the thermal break should help disrupt the transmission of certain frequencies). Modern engineered wooden windows can be acoustically good too but there are arcane influencing factors like wood type, grain directionality and multilayering which few in New Zealand will be familiar with, and good wood windows are expensive. PVC lacks the thermal mass to be the best at defeating low frequency sounds. Thicker high end PVC profiles should work better than low end but they are uncommon in New Zealand.

Seals on some sliders don't close very tightly or may have adjacent brushes instead of pressure seals. This is independent of frame type and is a design or manufacturing issue. Lone single point latch handles aren't always sufficient for holding a window closed tightly, so ask for two, or more ideally get multipoint locking. Nulook and Fairview/Elite aluminium joinery supports multipoint locking while all PVC sold in New Zealand should support it. The "Avon" single point handle available for wood or aluminium frames has 4 screws instead of 2 which should reduce the likelihood of loosening in the future.

Glass does influence acoustics but it's more complex than a simple case of single versus double glazing. With all other things being equal, two panes of 4mm glass doesn't make a vast difference over one pane of 4mm. If you're concerned about reducing noise with your double glazing you need to ask for laminated glass. The laminate interlayer breaks up the transmission of medium frequency sounds (much like the break in thermally broken aluminium) and performs substantially better than simple double glazing for sound reduction. Above that you can ask for an acoustic laminate, which is softer, thicker and unfortunately more expensive. In double glazing an acoustic laminate doesn't make a vast difference to total sound transmission but it tends to reduce the most offensive noises. For low frequency sound it's total thermal mass that matters far more than lamination so having the outer pane being 10 to 12mm thick to accompany the laminated inner pane should help with that if bass noise is a huge problem. 10mm / 12mm panes might be more expensive than a 10.38mm / 12.38mm laminate so check prices.

There is a light quality penalty to extra thick glass as iron in the glass has a slight green tint. It is possible to get "high clarity" glass without this issue but it's costly and not well known outside of Europe.

For the absolutely best noise reduction you'd want an additional secondary glazing frame with 125mm+ offset. There aren't many companies doing that in New Zealand.