Renewable Energy is Great, but ……..

  • Building Design Expert
  • 5 years ago

You hear endless chatter. Read countless articles and blogs on sustainability of materials, manufacturing processes and construction methods. The movement in these areas has always been there, but has gained huge momentum, and considerable recognition particularly over the last couple of years. To the extent that some local planning authorities are exercising their rights to insist on even higher code levels for construction of ‘sustainable homes’ than have officially been introduced.

A good thing, this then? You might say. To force the issue to within the achievable limits of current, or even breaking technology. Well yes, and there again, perhaps No.

I was recently involved in the design / build of a small housing development; just six units. We had obtained planning permission, and at the client / developer / builder’s request were in the process of pushing and pulling the interior layout, details and construction methods (without affecting the external appearance that we had fought so hard for with our friends at the LPA). Having agreed a reasonable set of compromises, the amended detail design went back to the energy assessor for what we thought might be a ‘rubber stamp’ and move forward.

I got a call from our EA. He said – “I can’t just make this work… As it stands we’re not going to make Code 3”. “How far away are we?…Did he have any suggestions to resolve the issue?” I asked. His response was that if we were to agree to include a ‘wood-burning stove’ (WBS) in each unit then that would “Eat the Code alive – no problem”. In fact he had already had the conversation with the client who needed a result and the project to start moving. He saw the WBS solution as a relatively inexpensive solution that would open this particular gate. So yes, decision made on cost. Building designer last to know. Don’t get me wrong. I wasn’t upset. More concerned at the process employed in the resolution.

At least four of the six units were not particularly suited to the installation of a wood burning stove in terms of basic layout, and what he failed to mention to our client was the need for a Mechanical Ventilation and Heat Recovery unit to replace our passive stack system we currently had – More cost. So what we gained on the swings we had to buy a lot more tickets for on the round-abouts.

Wood burning stoves of course need a liberal supply of oxygen to avoid the occupants suffocating, and if the air was being removed by it and the passive stacks……… I’ll leave you to work that one out.

The thrust of this argument is therefore that whilst we may coax, gently easing our renewable square peg into an available round hole, it may plug the gap, but in not being the perfect fit it becomes an effective hole in our armour. In this instance would a greater air-tightness coupled with MVHR have ticked our box? I don’t specifically know, mainly because we did not explore the options, and indeed arrive at the best solution. After all we didn’t need to “…eat the code”, we just needed to meet it.

So building designers need to start thinking ‘outside of this particular box’. It’s pretty much a ‘given’ that in order to meet looming targets for zero carbon – buildings will need to include energy ‘Renewables’. If we do not monitor the progression of this too many are going to fall into the awaiting trap of the Renewables Bran Tub. – “Just dip in and pull out your Renewable sir”.

Retail giant Marks and Spencer have shown some remarkable sensitivity, coupled of course with with good business sense in their development of a mini-store with a large sustainable ticket on it. They freely admit that there was a capex overrun on their renewables installation, but it was going to be recoverable within three years.

So what did they do?

They calculated that they could derive all of the space heating they needed by installing a heat recovery unit to capture the latent heat generated by the chiller and freezer display units and redistribute it back around the store. No boiler. No other heat source. Wasn’t rocket science was it? Just a little lateral thinking which I dare say will become part of the standard mechanical design pallet from here on in.

A whole series of interestingly sustainable features brought this store to opening – Check out the video below:

Video produced by Building Client Solutions in association with Dulux Trade Contract Partnership. For more information please visit http://www.building.co.uk/duluxtrade

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