Category Archives: Residential

Reducing Noise with the Right Windows

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Acoustics should be an important consideration when building your home.Australia’s growing population has resulted in a shift towards higher density residential and commercial constructions. In order to satisfy the expectations of the occupants, the acoustic performance of the construction and its openings requires careful consideration. This post is aimed to provide a general understanding of what options are available to increase the acoustic resistance of glazing.

Understanding Acoustic Ratings

Weighted Sound Reduction Index (Rw)

Road traffic is one source of unwelcome noise.
image courtesy of ziptrivia

Rw is the current Australian and ISO Standard acoustic rating method – AS/NZS 1276.1 1999 & ISO 717 1996. Designed to estimate the acoustic performance of a material or construction for certain common sound insulation problems. It contains two sound adaption terms (Ct and Ctr) so that the Rw value can be modified to reflect the environmental conditions to which the element or construction will be subjected. The Ct or Ctr term is added to the calculated Rw value to provide an indication of the performance under the adjusted sound condition.

Ct “Pink Noise” Spectrum Adaption Term.

Ct is used to adjust Rw to compensate for noise sources such as: high-speed traffic, children playing, noise from radios TV’s, high speed railway traffic and from factories that emit medium and high frequency noise.

Ctr “Traffic Noise” Spectrum Adaption Term.

Ctr used to adjust Rw to compensate for noise sources such as: low speed urban road traffic, factories that emit low / medium frequency noise and aircraft at close range.

Methods to improve acoustic (Rw) ratings

1) Decreasing the amount and volume of direct transmission paths through the glazing.

There is little point spending lots of money on upgrading to a high performance glass product if the window frame and seals are not upgraded. Air tightness of the window construction in particular, has been experimentally proven to be the most cost effective method of improving the Rw value of a window. This because each opening in the window, frame and seals provides a direct transmission path for sound to pass through. By reducing the number and area of these paths more sound must pass through the ‘barrier’ ie. the glass improving the overall performance of the system.

It should be noted that in some products the introduction of tighter fitting seals will reduce the overall day to day servicabilty of the product. For example – a sliding window may become difficult to slide due to the requirement to increase the size of the seal. In these cases it may be better to look for an alternative solution.

Frequency spectra for 4mm, 6mm and 12mm Float
Glass showing how the coincidence dip occurs at
different frequencies for each glass thickness.

2) Increasing the thickness of the glass

Thicker glass vibrates less than thinner glass, consequently the amount of sound able to pass through the window is reduced. Unfortunately this increase in glass thickness is limited by a phenomenon known as the ‘coincidence dip’. The coincidence dip is a frequency range over which the transmission of the sound increases through a material. The location of the coincidence dip is dependent on the material’s weight and its inherent stiffness. If not for this phenomenon, thickening the width of the glass would be the solution to all window acoustic problems.

3) Moving from a monolithic to a laminated glass construction

The effect of lamination on the sound insulation of glass.
Note the coincidence dip for solid glass is virtually
non-existent for laminated glass.

Laminated glass consists of two (or sometimes more) sheets of glass bonded together with a plastic interlayer. This plastic interlayer provides a damping mechanism in the glazing (the interlayer actually absorbs vibrational energy). This damping mechanism is particularly effective over the coincidence dip in the transmission spectrum. The result is that the coincidence dip is minimized and the overall performance is increased. A somewhat recent advance in laminated glass has been the development of ‘acoustic’ interlayers. These have been specifically designed to further reduce the coincidence dip, which maximizes the performance possible at each construction thickness.

4) Changing to an Insulated Glass Unit (IGU) Construction

Insulated Glass Units (IGU) consists of two glass sheets separated by a spacer to form an air gap between the sheets. This allows each glass sheet in the unit to act as a separate barrier to the transmission of sound. Unfortunately the spacer separating the sheets effectively forms a small short-circuit in the system. The spacer itself provides a direct path for the sound vibrations to be transmitted from the external glass sheet to the internal sheet of the IGU. This short circuit could obviously be eliminated by removing the spacer. This is not however a viable option – it would directly result in condensation in the IGU as well as allowing dust and particulates to deposit onto the internal faces of the two glass sheets.

Very large air gaps are more effective at reducing sound transfer than smaller air gaps. In practice, increasing the air gap from 6mm to 12mm provides little benefit. Substantially increasing the air gap to over 90mm however provides a large increase sound reduction. This anomaly is due to air trapped inside the unit acting as sound transfer mechanism between the glass faces of the IGU. As the air gap approaches 90mm this effect decreases in its severity.

Conclusion

There are numerous approaches that can be used to improve the sound resistance of a glazing and more often than not the most appropriate solution is a combination of one or more of the methods listed above. G.James has conducted extensive acoustic testing on our windows and doors. For further information on the choosing the right product for your project, please contact us.

Choosing the right windows and doors for your climate

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Windows and Doors to match your climate

Windows provide light, fresh air and great views to the outside world, but they can also be a major source of heat transfer, making your home unbearably hot in summer and freezing cold in winter.

Recent advances in glazing materials have improved the performance of windows to the extent where choosing energy efficient windows can prevent heat transfer, significantly reducing your energy costs and make your home noticeably more comfortable.

Different climates across Australia

Australia has 8 zones ranging from hot (zone 1) to cold (zone 8).Australia has a diverse range of climates. The National Construction Code divides Australia into eight different climate zones. These climate zones can be grouped more broadly into three climate categories, which describe the predominant conditions in the area:

  • Hot Climate (zones 1, 2 & 3)
  • Mixed Climate (zones 4 & 5)
  • Cold Climate (zones 6, 7 & 8)

Hot Climate

In hot climates, cooling your home and preventing heat gain is a high priority. When choosing windows, look for types with a lower solar heat gain coefficient (SHGCw) and those that provide good ventilation such as G.James 050 Series louvres. Choose products glazed with a tinted glass or one of the high performance products from the G.James SOLECT® range.

Cold Climate

In colder climates, heating your home and preventing heat loss is the priority. Heat loss during the cooler, winter months can be reduced by installing window types with a lower U-value. Choose products that are double glazed such as G.James Twin-Glaze or ecoTHERM insulated glass units (IGUs) or one of the high performance products from the G.James SOLECT® range. Maximise the passive solar gain by choosing a glass eg clear, which has a high solar heat gain.

Mixed Climate

In a mixed climate both heating and cooling your home are important, so consider which of these is the primary concern. Depending on whether you’re looking to focus on heating or cooling, you should refer to the relevant recommendations above. If neither heating nor cooling is the priority, choose a window with a lower U-value and a mid-range solar heat gain to provide good year round performance.

Heating/Cooling Stars

You can find cooling and heating stars against all our window products in the professional centre of gjames.com.

Between 46%-61% of a home’s heating energy can be lost through windows, while  79%-86% of heat can be gained. Therefore improving the thermal performance of a window can massively reduce energy costs and greenhouse gas emissions. WERS (Window Energy Rating Scheme) rates the energy impact of residential windows in Australia. Energy efficiency of windows is rated using the WERS heating/cooling star system.

  • Cooling stars measure a window’s ability to retain heat within the home.
  • Heating stars measure the ability of a window to reduce the amount of heat gained from sunlight.

The aim of WERS is to help home builders and home owners evaluate the relative energy (heating and cooling) performance of different types of windows by rating that performance in terms of stars. Having no stars indicates a very poor performing window while ten stars signifies superior performance.

G.James provides a comprehensive WERS search for all G.James window products. It can be found in the professional centre of gjames.com.

Other Heating & Cooling Factors

Windows with large opening areas maximise opportunity for ventilation and cooling, but larger areas can reduce energy efficiency. Installing an awning or a sunshade over a window will reduce the impact of solar heat gain, and effective window configuration can also improve seasonal efficiency. Knowledge of these factors will help you make an informed choice, but an experienced local glazing professional can also help you devise a solution to suit both your preferences and local conditions.

Project Update: Hamilton Harbour

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The third stage of the Hamilton Harbour development is now under construction.

Situated on the north shore of Brisbane River just a few kilometres outside the CBD, Hamilton Harbour is an exciting mixed use development with excellent city views up the river.

The project is designed by Cox Rayner Architects and is a joint venture between developers Devine Limited and Leighton Properties.

The Project

The first stages of the project saw two residential buildings constructed, both of which have been fully completed with residents already moved in. The final stage will see an additional residential tower and up to two commercial buildings built on the site.

The first two residential towers, Harbour One and Harbour Two, are 22 and 19 stories respectively. They were constructed simultaneously and completed in November 2011.

The third stage commenced as these buildings neared completion, when construction of Riverside Hamilton, a twenty storey residential tower began.

The first commercial office building, named “KSD” after the adjacent Kingsford Smith Drive, is 5 levels high and presently under construction.

G.James has been working to supply windows, doors, shop fronts and façade glazing for all four of the present buildings.

Reducing Traffic Noise

While energy efficiency is one of the most important factors in the design of a building, given the close proximity to busy Kingsford Smith Drive careful attention has been taken to achieve a high standard of acoustic performance as well.

To achieve these ends, a number of high performance products have been incorporated into the design.

  1. The 550 Series Balcony is a glass and aluminium balcony, which offers stunning views but also helps protect from the elements.Apartments with sliding doors incorporate the G.James 445 series sliding door system, and are glazed with IGUs for their sound deadening properties. The fixed windows use the 451 and the higher rated 651 series pocket framing systems, also both designed for accommodating IG units.
  2. Alfresco bi-fold doors in the apartments use the 477 series bi-fold door, with a 550 series glass balustrade on the balconies for excellent views.
  3. The ground floors of the residential buildings have been glazed using the 650/850 series shop front glazing system.

Acoustic performance was particularly important for apartments on the road side of Riverside Hamilton.  In these apartments an acoustic door arrangement was used to achieve excellent noise isolation, comprising a 445 series external sliding door with a 245 series internal sliding door.

Construction

The simultaneous construction of Harbour One & Two initially posed some challenges for the G.James Eagle Farm factory, as it was already working on two other high rises at the time. To cope with the demand, the work was spread between the Kingsford Smith Drive and Gold Coast factories to deliver results on time.

At present, construction on Riverside Hamilton is wrapping up and work is well under way on the commercial KSD building. G.James has commenced work installing frames for the ground floor shop front, and will be installing the curtain wall façade in the coming months.

G.James is pleased to have been working very closely with Devine on this project to achieve the desired outcomes, and look forward to further developing our working relationship. Stay tuned for the final article and more photos of the finished project.

5 key points for choosing windows & doors

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Choosing Windows and Doors

On average, glass comprises around 25% of a home’s external surface. Along with providing light, ventilation and protection from the elements, this makes choosing the right windows and doors one of the most important decisions when building a home.

These five key points highlight some important aspects to consider when selecting the supplier of windows and doors in your new home.

Australian Window Association

Compliance & Certification

Is your window supplier an Australian Window Association (AWA) member?

The AWA Product Accreditation Program ensures that accredited members manufacture their windows and doors to exacting performance criteria.

AWA members are also required to produce windows and doors which meet the requirements of all relevant Australian Standards are subject to third party annual audits to ensure continuing compliance.

More information on the benefits of dealing with an AWA member can be found on the AWA website.

Colour Selection

Aluminium Colour Range

Choice of frame colour can be an effective tool in either complementing or contrasting your interior and/or exterior colour schemes.

Aluminium windows can be ordered in either powder coated (painted) or anodised finishes offering you a wide selection of colours. An example of typical colours available in anodized and powder coated aluminium can be found in the G.James Colour selector.

Your chosen finish must also be able to withstand exposure to the elements, so a reputable supplier will provide a guarantee against premature weathering of surface finishes.

Glass Selection

The correct glass selection can offer a number of benefits.

  • Reduced external noise.
  • Savings on heating and/or cooling costs.
  • Extending the life of soft furnishings.
  • Reducing glare.
  • Improving security.

The basic type of glass used depends on application – in areas where accidental impacts are a concern, toughened and laminated glass are much stronger and safer than regular annealed glass. Using annealed glass in areas where the extra strength is not of tangible benefit is however more economical.

Climate is another major factor in the selection of glass – in warmer climates toned or coated glass will offer performance benefits, whilst in cooler climates IGUs (double glazing) will improve heat retention.

The most suitable products for a home will vary on a number of factors, so you should speak to a professional to discuss your requirements.

Features and Benefits

Price should not be the only consideration in seletion of windows and doors – value should also be assessed in terms of the extra features and long term benefits offered by the product.

So before deciding on who will supply your windows, ask the following questions:

  • Does the window have a rigid PVC sill insert for weather performance and easy cleaning of the sill? A threshold (cover) in the door sill should also be present.
  • Are the flyscreens easily removed both internally and externally? This is an important feature, particularly for two storey homes.
  • Are window handles located in the centre? Handles located at the jamb (side) can be difficult to access behind curtains or operate when fully opened.
  • Do the window rollers contain stainless steel bearings, important for long term performance?
  • Are the window rollers of sufficient size? Smaller tyres can develop flat spots which causes the roller to skid along the track rather than roll.
  • Are the rollers height adjustable?

After Sales Service

In the event of faults with sliding windows, doors or associated hardware, you must be able to rely upon your supplier to rectify any issues.

A written warranty from a trustworthy and well established company gives you peace of mind of knowing that you won’t be left out of pocket if something does go wrong. It is necessary to read and understand your warranty agreement to know the conditions under which you are covered.

It is also important to choose a supplier who offers a stable product line with standardised features and parts across their products – you don’t want to be left with non-functional windows or doors because the supplier can no longer obtain the right parts. A supplier must also keep sufficient stock/parts on hand in order to rectify faults quickly.

Ask an Expert

Researching your window and door options will help you make an informed choice, but don’t hesitate to consult with an expert for help in selecting the ideal windows and doors.

An experienced local glazing professional will help you tailor a solution to suit both your preferences and local conditions.

Revitalising a classic home with natural light

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Our Gold Coast Branch has recently completed the renovation of a large architect designed home situated in the Gold Coast hinterland. The scope of the renovation focused on improving the use of natural light while also creating warmer, more appealing living and entertaining spaces.

The Renovation

The hinterland region has a mild climate in summer, and can get quite cold in winter. With this in mind, Solect® Clear laminated glass was specified on certain elevations. The Solect range of glass products offer high performance qualities in both solar control and light transmission.

Large fixed windows were installed to maximise the amount of natural light allowed into the home. The unusual shape of the building required custom framing to accomodate the rake of the roof.

Frameless Glass balustrading was used on the staircase, and clear laminated glass flooring on the upper landing to further aid the spread of light throughout the home.

Sliding doors were used to expand the living space of the home outside in good conditions, with awning windows above to allow for additional ventilation.

Industry Awarded

This stunning renovation has gained well deserved recognition from industry bodies having received the 2012 Glass & Aluminium Association of Queensland Award for the Best Use of Glass & Glazing – Residential and, more recently, the Australian Window Association’s 2012 award for the Best Use of Windows & Doors in a Residential Renovation.

Who was involved

The Architect responsible for the design of this major makeover was Paul Uhlmann, and the project was managed by Graeme Cameron Constructions.  The windows, doors and specialised glazing was supplied by the team at G.James Gold Coast.

Get In touch

G.James has the product range and experience to ensure your next project is an outstanding success. To find out more please contact your nearest branch.