Retrofit Coordinator advice

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It came to my attention that Greening Hambledon and Winchester Action on Climate Change were running a free ‘Retrofit Advice Surgery for Old Buildings‘ – the timing could not have been better!  Along we went and discovered we had 1 hour to talk to a planner from Winchester City Council (not relevant as ours is not listed), a Retrofit Coordinator, and a specialist architect (MCMA Design).

We started with the Retrofit Coordinator and explained our situation.  We told him that we had thick flint walls and asked if the thermal mass was enough to insulate.  We learned that no matter how thick the wall (unless dealing with extremes) the warm heat will travel to the outside of the building and so insulation is essential, particularly if putting in renewable energy such as an air source heat pump as this runs at a lower temperature compared to oil or gas heating systems. Basically the maths needs to look at fuel costs vs insulation costs over a long term.

Next we needed to understand our walls.  These need to ‘breathe’ so that moisture can move from inside to outside the building.  Rain will also travel into the wall but will evaporate outside as the weather changes.  The key is not to make the wall watertight or airtight as this will cause damp.  We need to investigate what plaster is on the walls now as it should be Lime plaster – and so we need to send a fragment away for testing.  Lets hope that comes back positive for Lime so we don’t have to remove the existing plaster!

When insulating walls it is often the case that people use batons and fix insulation to that.  With older buildings this cannot be done because the gap in the middle collects air and when the air hits the outer wall it condenses and produces water = damp.  So the insulation needs to be directly against the wall.  We were shown two main options 1) an insulating plaster with cork in the makeup (photo Diathoneite Evolution with the sample next to it)  2) wood fibre ( photo pavatex).  See photos.  The jury is still out on which to choose but at the moment I favour the wood fibre for ease of installation (my theory!!). 

We also need to consider roof insulation and there is a new bit of kit that takes the insulation over the outer wall but keeps the air flow over the insulation from outside – we will investigate that further (no photos yet).  Pipe insulation that is of higher quality than usual also needs to be considered (see photo).

We also need to consider insulating the floor.  He showed us glass-crete which insulates and does not transfer moisture but this will need digging out the floors – but could then include underfloor heating. More decisions.

We then moved on to speak to the architect who reinforced all the above and also spoke to us about a possible extension to replace the tatty conservatory at the back of the building.  Timber framed?  Metal roof due to lack of height options?  Lots to consider, but I think the extension is the easy bit.  This brings home the point that when building from scratch we need to do it to the highest standards for insulation because this is the cheapest way of doing it – waiting to do it after the property is built creates huge costs and eternal decisions.

We also discussed air source heat pumps and the level of heat generated by them – it is low background heat but the property should be insulated and so the heat should stay at about 18 -20 degrees.  Obviously the more heat you generate, the higher the electricity bill and so as mentioned before, insulation is key.  We could also look at Photovoltaics to generate the electricity for our own use – more decisions and exploration.  My understanding is that we already all understand this technology as we all have a fridge and it is essentially this working in reverse – not rocket science!  There are three bits of kit 1) Water tank and lots of buttons  2) the square box that creates the heat from the outside air  3) radiators and these should be larger than usual or underfloor heating is also an option. We had a fantastic few hours and came away with our heads spinning, but also very excited to have some ‘real’ advice.  We went to the Sustainability Centre Beech Cafe for sustenance and a good old fashioned chat!  Wonderful.  ‘ What next’? I ask myself.

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