New Zealand has a love affair with BIG windows and why not when the reward is so great. Rugged mountains, deep lakes, crashing surf and lush forests, it is all there to enjoy from the comfort of your living room, so long as you have BIG windows. What however, is the real price to pay for something we cannot really do without?

Following on from my last post on ecopsychology, I would like to explore a range of building elements that constitute a boundary to the rest of nature, starting with windows and how they offer an opportunity to blur this boundary.

New Zealand has only recently made double glazing in new buildings compulsory, in part; and with replacement double glazing almost non existent, it is left with a legacy of buildings having huge single glazed windows that freeze on the inside during winter! Thus, not only is excessive heat lost during the winter, but unwanted solar heat is gained during the summer.

New Zealand has previously been able to enjoy low density, low rise buildings, but with land rapidly being gobbled up, the government is increasingly prescribing much higher densities. Privacy and acoustic protection are of much greater importance in high density developments, with which big windows are incongruous and thus present a challenge.

So, are we going to be seeing buildings with much smaller windows in the future? Well I hope not, because there are so many rewards to having big windows. The obvious ones are sunlight and daylight, without which, our buildings would become very depressing places indeed, not to mention reliance on artificial lighting. Sunlight also provides us with passive solar heat gains, especially useful in winter, as well as health benefits.

Open-able windows allow us natural ventilation, which is considered much healthier for our internal environments and mitigates the need for mechanical ventilation and unnecessary energy use.

Big windows also provide us with a visual connection to the outside, and are a simple method of blurring the third skin that is our barrier to being an integral part of the natural world. Big windows in New Zealand are here to stay, so what could be done to mitigate their disadvantages?

Glazing options

Double glazing, or better still triple glazing, is one of the most effective ways to keep heating loads to a minimum. It has the added advantage of eliminating surface condensation thus maintaining a clear view. However, with legislation in its infancy, demand in New Zealand remains low, making it often prohibitively expensive, especially for larger windows; although, the cost will inevitably reduce as the demand rises.

Frames

For the past forty years, New Zealand has favoured the thin aluminium frame because it is cheap and easy to install, but without a thermal break, it conducts heat just as fast as the glass. Simply returning to chunky timber window frames could help to resolve this problem, as well as improve the aesthetics, in line with current trends. Timber has the added advantage of being a renewable, recyclable material with low embodied energy.

Added features

Shutters are commonplace in Europe, but not here in New Zealand. Internal or external shutters, especially insulated ones, are a cost effective way to improve the thermal performance of windows. You could also go one step further by automating them; incorporating heat or light sensors.

Solariums or sunrooms were favoured historically as a way to provide a warm, sheltered space where the view could be enjoyed without losing heat from other areas.

Rooflights are an effective way to get adequate day/sunlight into a building while keeping aperture size to a minimum. Therefore, if a view is unimportant, or for high density areas, rooflights would be the best way to maximise natural light, while minimising heat loss.

By using deciduous vegetation as solar attenuation, the excess heat gains can be minimised in the summer whilst exploited in the winter, when the vegetation is leafless, negating the need for mechanical shading devices.

As a final idea, heat loss due to larger windows can be offset by optimising the thermal performance of other elements such as walls, roofs and floors.

BIG windows are an intrinsic part of New Zealand architecture and are likely to remain, but there are ways we can keep them, without the associated energy loss and discomfort; we simply have to think more holistically about the design and be more inventive when refurbishing existing buildings. By ignoring the drawbacks to these super size windows, we are building ourselves a very uncomfortable future.