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As if the implications of the unfolding global financial crisis weren’t bad enough, the Irish economy must also contend with the consequences of a banking system exposed to unprecedented property-related debts. Reflecting on the ongoing crisis, Richard Douthwaite explains why investment in local energy innovation may prove the key to improving Ireland’s economic health
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The entire south facing aspect of the BedZED apartments uses winter gardens to let light and heat in
Despite the solutions that are out there, despite the well-established trend in building regulations, Stuart is far from convinced that these alternatives are anywhere near design mainstream. “We’ve been involved in several schemes over the last year where the design was started literally years ago, now they’re coming to us just before planning application for advice on what we need to do to meet regulations, and it’s a huge problem because the roofs are all over the place...If the roof isn’t facing the right way, where do you put the solar collectors? We’re saying to architects, listen guys, next time before you sit down and start drawing, you’d better start thinking about this. It’s a real issue and it’s a significant cost if you don’t deal with it from day one. I think this is absolutely key to housing going forward in Ireland.”
These problems are not restricted to domestic construction. In commercial architecture, the trend towards overglazing has engendered a situation where daytime overheating has to be met with huge amounts of plant and energy – causing needless increases in capital and running costs. Architect John Goulding says we’re still in a situation where our decisions are being governed by agendas that have nothing to do with the environment. “Estate agents will tell you in the case of an office building, if you want to get a premium tenant, you have to get a highly glazed facade, which is a load of baloney. It’s an ill-informed view that that’s what clients like, and of course architects are often wooed by the look of glass buildings because they can look more exciting than buildings with an appropriate glazing ratio.” Falling for this trend leads to the designing-in of problems which then have to be countered with what Goulding calls ‘green bling’. “They’ll tell you that they have a highly efficient heat recovery or air conditioning system or whatever, but it’s bringing an inefficient solution to an inefficient problem. It’s far better to get the building to do most of the work for itself, and then you’ve minimised the problem, whether it’s heating, lighting or even cooling.”
The second endemic problem Goulding identifies relates to the way in which design team fees are structured on larger projects. “The building services engineer’s fee is typically based on the value of the building services equipment that they specify so there’s little incentive to reduce the amount of kit. Often from the first meeting they’re talking about chillers and fans and so on, all the machinery they can buy off the shelf and quite often the architect isn’t sufficiently well-informed or confident about these things to say hold on, do we need all this stuff? Can I not do things to the building that obviate the need for it all?” The obvious solution, which some developers have adopted, is to free up the fee structure in order to remove the incentive, leaving the engineer free to work with the architect to develop cheaper, more innovative solutions. Goulding would also like to see more building physicists on Irish design teams. “They bring a knowledge based on the actual physics of the building’s performance which can offer a refreshing new perspective on procuring an energy efficient building...Once it’s known that you have a site with certain characteristics and constraints, a number of environmentally workable strategies may remain open for investigation. If you know that you’re going to build a building of so many square metres for a particular purpose, you’ve got to have an envelope to enclose that. And the first thing they can do is look at the daily and annual energy requirements for heating, lighting, cooling and ventilation and get the optimum performance out of the building by manipulating building shape and glazing ratios.” This approach means the architect, based on the knowledge gained from working with the building physicist, can begin to design the envelope and express the environmental performance of the building in architectural terms with some confidence.
Glazing of course also has a huge bearing on the building’s relative
independence from artificial light. Chris Croly, environmental
engineering director with BDP says that traditionally, architects have
guessed daylight levels in different rooms, working off glazing ratio
rules of thumb. But given the range of additional variables; the depth
of rooms, the height of windows, the reflectance of different textures
and colours and urban overshading to name a few, spaces often end up
with insufficient levels of natural light. Simple spreadsheet
calculations can provide limited insights, says Croly, “but we use more
advanced techniques that will take into account the height of the
window in the façade, the exact position of the window in the room. You
would also look at things like transfer glazing - if for example you’re
bringing daylight into a room through an atrium, then transferring it
through a wall into another room.” Using light shelves as design
features help carry the natural light deeper into the space without
generating any further energy load. Achieving a daylight factor of only
five per cent – that’s five per cent of the lighting level measured
outside in a shaded area – means you can leave the lights off for 80
per cent of the time during normal business hours. “There’s an
incredible amount of daylight available.” says Croly. “For 50 per cent
of daylight hours, the light level outside is 15,000 lux. Inside a
building you need just 300 lux, so there’s a staggering amount of light
available. We just leave it outside most of the time.”
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Issue 2, Vol 5 Out Now
The new look issue of Construct Ireland is available now. Click here to subscribe online and have the latest issue delivered to your doorstep
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