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Archive for July, 2012

Can the planning system reduce the environmental burden of nappies?

By Rob Borruso

Having recently wrecked my environmental credentials by having a second child my world is again one of nappies and sleepless nights. Of course we’re told the most sustainable nappy is a reusable one so they’re hanging up everywhere at home, which got me thinking…

Now, I’m not going to use this blog to do a life cycle analysis of nappies but rather to show just how difficult they can be and include things you’d never think of. The case against the disposable nappy revolves around two points; the resources consumed to make them and the space they take up in landfill. The former I’m not going to question but the latter….. I’ve got some issues.

Over 80% of the weight of a used disposable nappy is water which, because the ‘damage’ caused by land-filling domestic waste is still measured quantitatively not qualitatively, appears to be more of a problem than it actually is. I.e. one tonne of water (which is inert) is counted as having the same disposal issues as one tonne of everything else that ends up in wheelie bins. Whereas, from a long term environmental perspective it really isn’t. So the damage caused but putting nappies in a wheelie bin really isn’t the same as putting in plastic coated paper- but is, nevertheless, not desirable.

Especially as there’s an eco alternative, the reusable nappy right? Well maybe. Reusable nappies do consume lots of resources, some obvious, and some not so obvious. Of course there’s the water, energy and chemicals involved in washing the things, but in my opinion these do not outweigh the issues associated with disposables.  But then come the less obvious issues, firstly drying (which I’ll return to later) and then there’s washing machine wear. A baby’s worth of reusable nappies will likely generate about 300 additional loads which is pretty close to the scrap life of a modern, (who bothers to get machines repaired?) washing machine.  So now in my view we’re pretty close to there being very little difference between disposable and reusable nappies and the argument starts to boil down to which is more precious, landfill space or water and energy.

With the case for reusables now weakened it wouldn’t take much to make the throwaway option better. This is where the huge issues around drying come into play. Nappies are difficult to dry – they absorb a lot of water they wouldn’t work otherwise. Therefore, drying them artificially, either in a tumble dryer (at least 2kg CO2 per load) or over radiators (which consumes just as much energy and can lead to condensation problems) can wipe out their environmental credentials. This is where that most overlooked but massively effective eco-gadget comes into play – the washing line. Even in my west of Scotland home we can get most of our washing ‘out’ on the line. Do architects and especially planners give much thought to this most cost effective energy saving device – no! Much greater effort should be made to encourage their provision and use. I know this is easier said than done. Experiences with communal drying areas (which CfSH does give credit for) that have been less than positive prove that, but really, is designing a washing line facility beyond the skill of humanity?

The point is planning can and should influence behaviour and its behavioural change that is the key to reducing resource consumption not £600m of PV subsidies given to the well off. The system that dictates the houses we should all live in seems, to my mind, to be far too focused on the wrong things; like whether the right shade of grey for the fake slate roof tiles occupies as much time as ensuring dwellings are suitable for a world in which oil is $200 a barrel. The home owners of the future will be much more concerned about their ability to dry clothes (and nappies) or grow some vegetables rather than the exact colour of their brick mortar.

 

What’s in a teapot?

By Jim Allen | E&M West Ltd |             www.eandmwest.co.uk

You see before you a photograph of a piece of domestic crockery, with a difference.  It has been the subject of DESIGN.  Its basic function is obvious but for the uninitiated in the art of tea making it is to contain high temperature liquid (water) allowing the diffusion and dissolution of various chemicals from a herbal product (tea).

It is dependent on the skill of its operator if the perfect cup of tea is to result, but we will not dwell on the number of tea spoons or bags, pre-heat, the precise water temperature or brew times here.  It is the impact of the pot itself that interests me, and the steps taken by its designers to improve performance.

Arguably this is a very sustainable tea pot.  In the first place it is reclaimed, having been rescued from a trestle in the Bude car boot sale for the princely sum of £5:00 (near closing, rainy day).

Moving swiftly from procurement I want to consider how design impacts its central function which is the ability to retain heat to enable sufficient brew time to get a strong hot cup of tea (and no, the microwave does not improve the flavour).

Immediately obvious is its cute wooden stopper snugly fitting its spout and preventing hot air rising and convection heat loss.  It sits very daintily on four spherical wooden feet.  In this context the wood is a relatively good insulator, and as there is only point contact, there is very limited conduction to any cold surfaces you might be foolish enough to sit it on.

This does however present a second design problem, as this encourages air flow around the hot body, with risk of heat loss due to external convection.  The designers have thought of that, and engineered (a subject close to my own heart) an insulated stainless steel jacket, limiting surface temperature.  The polished surfaces internally also reflect radiant heat energy further enhancing performance.

But wait, I hear you say, stainless steel is a very expensive and scarce resource, and its manufacture will have consumed much of the earth’s limited stock of raw material.  Some truth there, but given this pot originates in the late 50’s, that steel was probably recycled from steam engine connecting rods courtesy of British Rail, and anyway, its robustness has allowed the teapot to survive its journey to the trestle and my car boot which means its been able to save energy for over 60 years.

And just think of those savings.  In my kitchen it keeps the tea warm for a good 20 minutes or more and I like it strong.  No more boiling of kettles to warm the pot for my second cup.  I will leave it to others (I am a structural engineer after all) to calculate the energy savings over a lifetime but they must be huge.

Hopefully the analogy with building construction is not lost on you, dear reader.  We should all be investing in good design and quality to ensure performance.  But beware, and don’t lose sight of pragmatism as we indulge ourselves in detail at an ever diminishing scale.

Remember, you can always consider the tea cosy.