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Your dream eco home brought to life: Meet the mind behind one of Merton’s first carbon neutral homes

Blog by Michael

Sustainable Merton Community Champion

When Robin Charlesworth invited Sustainable Merton to visit the ‘carbon neutral’ family home he had built at the bottom of his garden, the opportunity was too good to miss.

We visited on a warm late summer's day and Robin explained how he and his family had decided to build themselves a new ‘eco’ home at the bottom of their garden in Colliers Wood. They were keen to ensure that it used as little energy as possible, but most importantly that it was a pleasure to live and spend time in.

The combination of high levels of insulation, an attention to airtightness and a high tech air source heat pump / mechanical ventilation heat recovery (MVHR) system ensures the home is snug in the winter and doesn’t overheat in the summer.

Robin reflected that whilst he had considered the loss of garden habitat, the green roof and courtyard garden helped to add back biodiversity. Plus the original house, which they sold after they moved out, was also left with a reasonably sized garden (by London standards!).

We asked Robin some questions to learn more and provide some inspiration to Merton homeowners who might be considering taking steps towards a carbon neutral home:

Q. Why did you choose to build at the bottom of your garden?

Robin: We wanted to build our own home, but stay local and this presented a great opportunity.

Q. Were there any parts of the build that were more expensive than you were expecting?

Robin: Definitely, the heating and ventilation systems were about 5 times the price of conventional heating installations. The cost of everything else was sort of as expected. However, there is a lot more stuff to buy and think about which pushed the overall cost up beyond original estimates.

Q. Was securing planning permission challenging? Were the local planning policies supportive?

Robin: Lots of people ask me this, but the truth is I don’t know. It’s a very opaque process and I don’t know if we just scraped a permission or we sailed through. People I have spoken to say that building eco should help with planning, but there is no specific policy as far asI’m aware and you are relying on the eco conscience of the planning officer as to whether it’s something they take into consideration or not.

Q. How long did it take to build and get planning permission?

Robin: It took 1 year to get permission and 1 year to build, almost to the day.

Q. How did you find builders who knew how to build at this level of quality?

Robin: I have used the main contractor before to do a few bits around my old house so I knew what they were capable of. The main thing I would advise when choosing a builder is to pick someone you trust and is open to new ideas. Lots of the stuff they did they had never done before, but it didn’t faze them, they embraced it and took it as the chance to learn something new.

Q. Were the neighbours supportive?

Robin: The neighbours were both fine. We had our ups and downs but generally, I could understand their concerns, we were building a house in our back garden after all!

Q. What would your top three tips be for others looking to do the same?


Tip One: Do lots of research. Once you go down the eco route it comes with certain requirements, like MVHR, so you are immediately into additional costs and a way of designing and you need to decide if you want/can afford that.

Tip Two: Decide if you're aiming for a standard, i.e. carbon neutral / Passivhaus etc before you start. You can then design to that standard from the start. Get a good thermal analyst and speak to them.

Tip Three: Stick to your guns. There is the chance to chip away at the econess all the way through the build and you need to be committed and stick to your guns. i.e. if you want a green roof, you may also need a stronger structure and a thicker roof membrane, both of which come with additional cost.

Q. What would you have done differently?

Robin: Not started in the winter. There was a lot of mud.

Q. What's your favourite feature?

Robin: The wildflower roof. The contrast between the modern solar panels sitting amongst the simplicity and naturalness of the meadow - I think it’s amazing. It's also great for nature so fits well with the ethos of the build.

Q. What's your favourite room?

Robin: The living room of course. It's big, light and a lovely place to be.

Q. What's it like to live in?

Robin: It's amazing, really unlike anywhere else I’ve lived. It feels really solid, I think because it’s so quiet and dark being away from the street. It’s always a lovely constant temperature and you don’t have to worry about the kids leaving the doors open on a chilly day, as the cold doesn’t seem to get it like it does in a conventional build. It really is a different experience.

Q. Are you saving on energy bills?

Robin: Oh for sure. I think we will produce a very similar amount of energy as we consume this year, however that will still leave us with a bill as the price the energy companies sell to you is a lot more than they buy your solar generated energy for. We do also get a grant of £360p.a. for the heat pump. Overall I reckon our bills will be approx. £150p.a. We used to pay £2,280 in our old house, so it’s a bit of a saving!

Q. Which "eco modification" would you recommend that someone starts with? (i.e. what would save them the most energy/money/carbon?)

Robin: Insulation and draught proofing are the key I think. Adding wall insulation and making sure it's continuous will definitely help, i.e. make sure the joints between roof and wall insulation are considered, don’t just stop one and start the other as you will get a big cold bridge. Draught proofing is also really key, there is no point sticking a load of insulation in your loft if your loft hatch is draughty, or double glazing your windows if your floors or doors are draughty. Most of it is common sense, but you need to be committed and do every detail you can.

Q. Were there any websites or other resources that you found particularly useful?

Robin: is really good for products and advice.

If you want to read more about this unique home this website provides more detail and beautiful photos:


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