Eco-scrutiny of my Eco-renovation

The first was a trio, including Sue Welland from Homesun – a company offering solar PV on a ‘rent a roof’ basis. If your house is suitable – generally that means with a south-facing, non shaded roof – they’ll install solar PV for free. Homesun then benefit from the feed-in tariffs and the householder gets free electricity in the day, when the sun is shining.

We knew my flat wouldn’t fit the bill because it faces East/West and the roof is partly shaded. But Sue brought along John Parker from Eaga, to show me how they went about their assessments. It turns out that my roof has another problem, that I hadn’t anticipated – it’s slate. The fragility of slate makes it more expensive to install solar PV.

The really good thing about the Homesun approach is that they won’t recommend solar unless it really makes sense – because they only benefit if enough electricity is generated. They’re also responsible for maintenance.

The third member of the trio was Tim Hipperson, also from Eaga. He was carrying out an energy assessment and making recommendations on what I should do. This led to in-depth discussion about saving water.

Both Tim and John were very keen on a gizmo called Shower Smart – Eaga are giving them away for free. As long as your shower isn’t electric, you can fit this nozzle-like device onto the shower hose – and it will reduce the amount of water coming through. I’m not sure whether I’ll be using it because my new shower, bath and loo will all be top of the range for water efficiency.

We also covered lighting, radiators, pipes, heating controls, thermostats, insulation and there were several ideas about how to extend the life of boilers. Probably one of the most important changes to my plans, prompted by Tim, was to abandon the idea of an electric towel rail. I’ve decided to have a small laundry room (I’ve moved the loo to make space for this), with drying racks. And I had thought that this might include one hot water towel rail and one electric one. But Tim pointed out that electric heating is very carbon intensive – and people have a habit of leaving towel rails on, so this could be very wasteful.

The following morning, John Doggart, from the Sustainable Energy Academy, joined me for breakfast. I’ve known John for over 20 years, although, until we bumped into each other at Ecobuild, hadn’t seen him in ages.

His approach was to measure up the flat and calculate its carbon emissions. He estimated that prior to installing a new boiler about 18 months ago the flat could be generating about 5.9 tonnes of CO2 per year. Post renovation he thought we would be reducing this by over 60% – but only if we added even more insulation than planned. John explained that although my flat has a converted attic, the neighbouring properties did not, which means they’d be cold. So now we’re adding those party walls to the long list of insulation plans.

John followed up with an email. The good news, he said, was that my flat will be eligible to join the growing number of Superhomes across the country. These homes have days when they’re open to the public, to give ideas on how to slash your carbon emissions. I’m not sure whether I’ll join the scheme – it will depend on whether I manage to find a keen, green tenant.

Once the flat is rented out again, the intense scrutiny may have to stop. But until then, there’s lots more to do. Builders should be starting work in May. I’ve been commissioned by the FT to write about it all in their Home & Property section. And there will be more blogs too.