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Insulation and Double Glazing not Eco Bling!

Most people now realise that the challenge in terms of housing stock and carbon emissions is not the new buildings but the old ones. 80-90% of our homes will still be standing in 2050.

Camden Council refurbished a four floor, five bedroom Victorian property to reduce carbon emissions by 80%. More than 1,800 people visited the Camden Eco House in the three months that it was open to the public on Sunday afternoons. An astounding 890 people looked round it during Open House weekend in September. It’s proof, if proof were needed, that people want to see how a solid wall Victorian property in a conservation area can be refurbished to reduce carbon emissions and energy bills by 80% whilst protecting our heritage.



The key learning from the Eco House is insulation,  insulation – to paraphrase a former Prime Minister. Roof insulation, basement floor insulation and external or internal insulation on all the exposed walls. The reaction of most people – especially in London – to internal wall insulation is “oh that means I’ll lose loads of floor space”. Not true. Remember you only need to do exposed walls. In most homes that will mean one wall in each room.

Add in some decent double glazing (because the seals in 35% of double glazing – the cheap stuff – fails within the first three years) and hey presto you have an energy efficient cocoon that requires virtually no energy to keep it warm. A few years ago English Heritage would have baulked at replica Victorian double glazed sash windows. Now they accept them. They have had to. Bluntly – there is no point protecting heritage if there is no human society left to appreciate it!

Double Glazing

Double Glazing

Wind turbines, photovoltaic panels, grey water recycling, ground source heat pumps – none of these make much sense for individual urban households. Wind is a complete no-no because you need huge blades to make wind turbines work cost-effectively and London simply isn’t windy enough. It would have cost about £10,000 to install a dual pipe system in the Camden Eco House to allow grey water recycling which would never have paid itself back because water is underpriced. And although I have a lot of time for ground source heat pumps, which extract solar energy from the ground, the reality is that they have mechanised parts that will break and it’s not clear a householder will recoup the £6,000-8,000 investment.

Solar water – using the sun’s rays to heat up water – will pay itself back within a few years. It’s estimated that solar water panels will produce 40% of the annual hot water needs of the Camden Eco House. But this house had a south-facing roof. Most households in London do not even have a roof let alone a south-facing one.

There are also photovoltaic (PV) cells on the Eco House roof to generate electricity. They are expected to provide more than twice as much electricity as the house needs over the year. In other words the house will be a net exporter to the National Grid. Great news you might think, but you would be wrong! At the moment PV panels are still very expensive and are likely to break before they pay themselves back. However the Chinese and Germans are investing heavily in PV so the price should come down in time.

A national feed-in tariff, which the government has finally agreed to bring in, should also help. It will mean that if you supply electricity to the Grid you will get paid more than it costs you to take electricity out of the Grid. Most European countries have feed-in tariffs, which is one of the main reasons why they obtain far more of their electricity from renewables than we do.

So on PV I would say watch this space. And in the mean time the lesson from the Camden Eco House is that we have to do the boring stuff not the eco bling!

Here is what will make sense for most homes in an urban area like Camden:

  1. insulation
  2. double glazing
  3. solar water if you have a south-facing roof
  4. localised heat exchangers (which are basically fans that expel stale air, bad smells and moisture but which use the waste heat to warm up incoming fresh air).

Now comes the real challenge. How do we do the rest of Camden? The Council has agreed to put cavity wall insulation in all housing estates, but that’s only a small proportion of Camden’s housing stock. And how do you persuade a private landlord to put in insulation when they don’t pay the energy bills?

In short, how do we industrialise and incentivise the whole of Camden to put in insulation and double glazing?

What about if the Council lends the money for insulation and double glazing to householders and private landlords or their tenants? An extremely rough and ready calculation, based on the Camden Eco House, is that this would cost £10,000 for the average Camden property. You would have to sign up to get it done by a Camden-certified contractor when they are doing your area. Your energy bill would go down after the work has been done. Camden could then recoup a proportion of the energy bill saving through the council tax.

Landlords should be happy because they would get an upgraded property for free. Householders or private tenants should be happy because they would pay less overall in terms of council tax plus energy bills. If someone moves, then the loan would stay attached to a particular property because the incoming owners or tenants would still benefit from lower energy bills. Camden Council’s Finance Director should be happy because he would get his money back in time. And environmentalists would be happy because Camden’s carbon emissions would go down dramatically and the UK would have a model that could be rolled out nationally.

Tim Wildes
Insightful articles on the environment, pollution, energy, recycling, green living, climate change and much more

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