Tag Archives: Renovation

How to Install Insulation

How to Install Insulation

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Insulation needs to be installed with careful attention to detail, as inappropriate or incorrect application will crucially decrease performance. For instance, failure to butt all ends and edges of batts to give a snug fit could mean that about 5% of the ceiling area is not being covered. This could result in losing up to 50% of the potential insulation benefits.

  • Avoid thermal bridges
  • Eliminate gaps in insulation
  • Do not compress bulk insulation
  • Protect insulation from contact with moisture, provide vapour and moisture barriers to prevent condensation
  • Provide a sealed air space of 25mm adjacent to reflective insulation
  • Allow clearance around appliances and fittings

All electrical wiring encased in insulation must conform to AS3000: Electrical installations-buildings, structures and premises. It’s best to keep wiring clear of insulation, e.g. to run wiring on top of ceiling joists.

Neither good performing insulation or a 6 or 7-star energy rating are a guarantee for real energy efficiency. The building envelope needs to be treated as a delicate continuous shell. Each small gap and leakage will impair the performance of the insulation. It is essential to consider the end product in order to determine how energy efficient a building really is. Even small gaps in the insulation such as around windows or other wall penetrations can halve the potential insulation benefits. Adding good performing and appropriately installed insulation can save a lot on your energy bill and minimise the greenhouse gas emission.

Why is Insulation so Important?

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Thermal insulation is a fundamental factor to achieve thermal comfort for occupants. Insulation reduces undesirable heat loss or gain and can lower the energy demand on heating and cooling systems.

Insulation is the most effective way to improve the energy efficiency of a building, as it acts as a barrier to heat transfer.

It will keep the house warm in winter and will help to stay cool in summer, improves thermal comfort and well-being, and minimises condensation on walls and ceilings. Furthermore, insulation needs to be combined with appropriate shading devices to windows and adequate ventilation possibilities, otherwise heat entering a building through windows will be trapped inside by the insulation and lead to overheating.

Older houses in particular pose a problem: inadequate insulation, poor solar access and air leakages amongst other things lead to unwanted heat gain and loss, and consequently higher energy bills.

Adding insulation to a home can save 45-55% of mechanical heating and cooling needs and as a result, save non-renewable resources and reduce greenhouse gas emissions. With the current energy prices, additional insulation usually pays for itself in around five to six years. With the prospect of rising energy prices it’s more than likely that insulation retrofitting will pay off even quicker.

How Much Insulation Is Needed?

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In short: the more the better:

The Building Code of Australia (BCA) identifies eight different climate zones for Australia, but within a zone, there are some locations with slightly different temperature ranges. There can be significant differences between maximum and minimum temperatures in summer and winter and in length and intensity of heating and cooling periods. The house design, the insulation and construction must respond to these variations in order to be able to perform energy efficient.
For simplicity, Victoria is divided in five climate zones, with winter heating as the predominant concern especially in the Temperate Coastal and Cool Inland Zones. Summer cooling is variable but generally less significant. House design in these zones requires attention to better performing insulation, draught proofing, window protection in winter and shading in summer. Likewise, in warmer cities and areas like Mildura supplementary heating is obligatory for thermal comfort. In these regions, it’s advisable to include extra thermal mass, cross ventilation and summer shading, whereas alpine areas may require constant heating for most of the year and cooling requirements are negligible. Consequently, a 6-star home in Mildura wouldn’t comply with the minimum requirements for a 6-star home in Ballarat.

The higher the R-value the better the performance. Consider what insulation is needed in order to build an energy efficient home in a certain climate zone early in the design process. In particular, it’s important to think about the roof insulation. For example, it would be cheaper to use larger rafters in order to fit in sufficient glasswool to fulfil the desired R-value, instead of using thinner expensive extruded polystyrene. Larger rafters would mean that the overall height of the building rises slightly. This is no problem, if the amendments are done early in the design. However, if a town planning permit has already been granted, it’s not that easy any more. It’s necessary to go back to the council with the changes, which can cost a lot of time and money, therefore in most cases, people choose to use the thinner, more expensive insulation instead.

Adding R1.0 insulation can significantly improve the energy efficiency. For example in Melbourne, adding insulation with a R-value of R3.0 to the ceilings and R1.5 insulation to walls can save 12% on energy bills each year and can ensure a higher level of comfort.

One important thing to consider is that the energy requirements as listed in the BCA are minimum requirements only, not best practice. So if someone is telling you to not put any more insulation in as the regulations call for: don’t listen to them. They don’t have a clue.

If you put in anything less, your building would not comply, so if you are after an energy efficient home, why would you be happy to only have the legally required minimum? Rather put in as much insulation as fits into the wall/roof/ or wall and as much as your budget allows.

Keep in mind, while it is quite easy and common to upgrade bathrooms and kitchens every 10-20 years, you will typically not touch the insulation again. So make sure you make your home future proof!

Air Leakage + Thermal Bridges explained

Capture3Imagine it is winter. You wake up in the morning, put on your favourite hand-knitted wool socks and walk to the kitchen to have breakfast. But something is different today, your left toes are cold, you start to shiver and feel uncomfortable. What happened? The fabric on the toes has worn-out, there is even a little gap. The socks that used to keep your feet warm and cosy have a leakage and they are not able to keep you warm any more.

The same principle applies to a house. The building envelope’s task is to protect its occupants from the environment and to keep them warm. The building envelope needs to be a continuous shell, each little breach will negatively influence the overall performance and reduce the insulation’s potential benefits.

The following will explain where air-leakages in a building usually occur and how to prevent them.

Air-Leakage And Thermal Bridges

Thermal bridges and air leakages will increase the need of supplementary mechanical cooling and heating, but they will also increase the Relative Air Velocity and the Mean Radiant Temperature which will negatively influence the well-being and the comfort of the residents. By applying the right design features, natural ventilation and cross ventilation can be used to control indoor temperature and therefore reduce energy bills significantly. For these reasons, controlling the air movement is essential.

Read our next article if you want to know more about where air-leakage and thermal bridges typically can occur.

 

Energy Efficient Window Design

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The total radiation received per window varies according to the time of the year and the orientation. In summer, all windows receive heat gains, in particular those facing east and west. Whereas in winter, only windows facing north, north-west and north-east have a net heat gain, with heat gains outweighing heat losses. Windows facing all other directions will affectively lose more heat than they can gain. However, in the absence of northern solar access, windows to the east and west can provide some winter heat gains.
The most appropriate size of windows in terms of energy efficiency depends on many factors, such as glazing type, orientation of a building and thermal mass located inside the building materials. It is important to consider every room separately, as each room may have different acceptable limits and therefore may need different sized windows. Thinking about the windows early in the design process can save time and money otherwise needed later in the progress, to chase after the required stars to obtain a valid energy rating. We can help determine the effect of variations to window orientations, window sizes, internal glazing, double glazing versus single glazing, shading and internal coverings by using the FirstRate House Energy Rating software. Below are some clues on how and where to place windows.

How to orientate and size windows


Windows should be orientated to the north where possible. If solar access is good, north-facing windows should be large, but the size also depends on the amount of thermal mass in the building. South and east-facing windows should be kept pretty small, and windows to the south need to be positioned to enable cooling summer breezes to pass easily through the rooms. Whereas west-facing windows should be avoided where possible, if needed they should be relatively small and well shaded.
Appropriate window sizing, combined with double glazing, and/or close-fitting internal coverings such as drapes with pelmets, can minimise heat loss in winter. Furthermore, it is important not to overshadow windows in winter by the structure of the building itself, as it will reduce the solar access.


How to respond to poor solar access

Innovative design can overcome problems of poor solar access and overshadowing, especially in renovations, infill developments, higher density or small allotments with bad orientation, which can cause problems. In these cases, it’s important to use better performing insulation, protect windows, minimise overshadowing and courtyards, and reduce air leakage as much as possible. To compensate for poor solar access, the total window area of a building should be reduced.

Where solar access to north-facing windows is obstructed, clearstory windows are a good option to get solar energy into the building. Another option in responding to bad solar access is raising the sill height, as it will minimise permanent shaded glass areas, as these aren’t able to gain heat in winter and will lose heat instead.
Skylights and roof lights are also a good way to bring light into rooms, if obstructions from other buildings and structures prevent good solar access. Furthermore it’s a great opportunity to overcome overlooking into neighbouring properties, as windows above 1.7m don’t need to be screened. However, it is vital to protect the windows against harsh summer sun. Double glazing is mandatory as well as shading (a combination of external as well as internal shading would be the ideal solution).

Insulation: What can we learn from Overseas?

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Thermal bridges

When I started working in Australia in 2007,I was puzzled how thin walls can be. For example, an external wall can 110mm, 90mm for the timber studs, 10mm plasterboard on one side ,10mm fc sheeting on the outside and insulation just between the studs. This construction in general is not allowed in most European countries, as it creates a structural thermal bridge. The U-value of timber is much higher than the U-value of the insulation, which means that heat can escape through the timber and consequently increases unwanted heat gain or loss. In Europe, the main focus lies on avoiding thermal bridges. A timber construction is usually done as a double stud wall. In this case, there is also a timber stud to the interior, covered with plasterboard and insulation between the studs, but at the outside is another continuous layer of insulation, and then another timber stud, with external plasterboard and again insulation in between. (see diagram below)
In Australia, there are no strict regulations about thermal bridges and also no minimum insulation regulations for concrete slab-on-ground construction, roof or internal walls.

Example for an insulation for a typical Australian home compared to a German home

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  AUSTRALIA (Melbourne 2015) GERMANY (2010)
External Wall R-value: 2.8 R-value: 5.0
Roof Not required R-value: 6.6
Ceiling R-value: 4.1 R-value: 3.3
Internal Walls                                         (to garage, bathroom, staircase etc.) Not required R-value: 3.3
Floor R-value: NIL for slab on ground

R-value: 2.25 for suspended floor

R-value: 3.3

Obviously, the average temperature in Germany is much lower than in Australia, therefore it is natural, that the R-values of the insulation need to be higher, but there are also some differences in where the insulation needs to be installed. In Australia, usually just the ceiling gets insulated, although the roof space is ventilated, heat can be trapped inside in summer which can transfer through the ceiling and heat up the rooms below. In Germany, the main focus lies on the roof itself, the whole outside of the building is treated as a continuous shell. Ideally, no heat should be able to transfer into the building at all. There are no wall or roof vents, most of the buildings are even air-tight.

For instance, in winter you can easily distinguish between a good and a bad insulated home in Germany. In a good insulated home snow won’t melt on the roof tiles, as no internal heat can escape the through the insulation which reduces the energy required for heating enormously. Furthermore, it is also a requirement to insulate the ceiling to a roof space and to floors/ceilings between different levels, as well as to place insulation on some internal walls, for instance walls between rooms with different heating requirements, to unheated corridors, garages etc. This is to stop heat ‘traveling’ through a house from room to room.

Furthermore, typical brick veneer constructions, as shown above, are not advisable, as the thermal mass is located on the outside of the building and therefore can’t be used to actively contribute to heating and cooling needs. Brick should be located on the inside. Therefore a better opting would be to use a reverse-brick construction, where the brick is inside the building envelope and consequently is able to store heat and to regulate the indoor temperature.

What can we learn from overseas?

Minimising thermal bridges and heat transfer is mandatory in order to create energy efficient and environmentally friendly buildings. All insulation must be installed snug-fit, there should be no gaps and also thermal bridges should be avoided where possible in order to minimise greenhouse gas emission and to protect the environment.

 

Apartment Renovation St Kilda – update

No matter how small or large a project, you have always to expect the unexpected. And no matter how well you detail and plan ahead, almost always there will be some complications or unexpected developments down the track, that will slow you down and will add to your well planned budget. Therefore it is imperative to always allow for some contingency within the budget as well as the time frame. And this is even more so the case when renovating. You never know what awaits you once you start pulling down walls, opening floors etc.

Even with this little straight forward renovation we had a few unfortunate setbacks, that did cost time and money. Originally it was planned just to replace the old dodgy power points with new ones. But when the kitchen was out the electrician advised us that the entire wiring was in a really bad condition, not up to current standards anymore and that he could not just install the power points as we wanted. We had to get the switchboard replaced as well as some of the wiring inside the walls. Which is a quite time intense and expensive job when working with massive brick walls throughout.

Also, once the old bath and the tiles came out we had to realize that the former plumber had done a really messy job, there where a lot of pipes where they didn’t belong and a lot more work involved then was anticipated.

Please check out the finished apartment under ‘Projects’

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view from living room into kitchen

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chalkboard wall in kitchen

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new shower in the making

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Apartment Renovation St Kilda

This small 2 bedroom apartment in the hear of St Kilda is getting a major face lift. New kitchen, new bathroom and a fresh splash of colorful paint including some new funky interior design features.

Stay tuned how this low budget renovation will transform the entire look and feel of the apartment.

Here some before shots.

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Existing kitchen

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Existing Bathroom

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Existing bath which probably never ever saw cleaning products….

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Living Room

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Bedroom

Construction Update St Kilda East – Sips Extension

Demolition has been completed for the renovatinon/extension in St Kilda East. The floor and the existing walls have been stripped and the first SIPS panels are getting installed.

Exciting times!

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The SIPS panels can easily be carried and installed without a crane, safing money during the construction.

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