Fran Smitherman

Hoping I've picked the right thread here... I'm having underfloor heating in my new summerhouse. I've rejected solar panels for powering the underfloor heating, so my next option is getting power from the mains. There's a charging point outside the back door of the house which we've used for charging up our mum's mobility scooter, and also plugged the lawnmower in there. I'm guessing we can have cable run from near the charging point to the summerhouse (2 metres away) which we would get a professional to do. My question at this point is: can we use an extension cable plugged into the charging point and powering the underfloor heating to test it out before chosing a professional to do the permanent set-up? Fran

This is indeed a new build and, yes, I would like to design in sufficient floor insulation. The idea so far is to make a concrete plinth 3 metres by 6 metres with the top surface 10 cm above ground level, then a waterproof barrier (plastic sheeting), then double skin breezeblock walls on 3 sides (west, north, and east) and 4.5 metres of patio doors on the south side, then insulation (J S Harris mentions 30cm of EPS) directly onto the waterproof barrier plastic sheeting, then 5 packs of B&Q underfloor heating pads (each 4 metres x 0.5 metre), then tiling. In this scenario the plastic sheeting is under the breezeblock walls but the insulation abuts the breezeblock wall and the heating pads abut the north wall but have a gap at each side (unless we can buy heating pads which are 4.5 metres x 0.5 metre). Do I need to think again? Fran

Our planned new summerhouse is to have underfloor heating. We can extend the cabling from the house to the new summerhouse 2 metres away. We may also power lighting and a TV from this source. If we want a display showing how much energy each of these 3 (heating, lighting, TV) is using, where can we buy meters to do this? I've tried the 'contact us' email link on the Friends of the Earth website (and have sent 2 follow-up emails in the fortnight since an automatic reply arrived saying email us again if you don't get a swift reply) but as am yet no wiser on this topic. Fran

I introduced myself about a month ago under the heading New Summerhouse. I had some interesting exchanges on solar panels to power underfloor heating in the summerhouse. I have now rejected this option in favour of a north-facing sloping roof (thus getting 3 metres of height at the south-facing patio-door-lined side) with no solar panels, and powering the underfllor heating from the mains. I've been to B&Q and looked at the sheets of underfloor-heating insulation sold there, which seem to be pink poystyrene 1 cm thick with a grey coating to each face. Is there a more eco-friendly alternative, perhaps on the lines of the shredded-paper insulation available for lofts. Perhaps not, as anything underfloor will get walked on/compacted and lose insulting capabilities. Fran

Thanks ProDave! The house roof faces east and west so possibly wouldn't be conveniently oriented to the sun for harvesting sun's rays. You may have noticed that, when I posted yesterday, I mistakenly gave the pitch on the north-facing part of the summerhouse roof as 60 degrees when I should have typed 45 degrees. No matter! The consensus of opinion among my siblings is to power the underfloor heating direct from the mains and, having decided again solar panels, to put a flat roof on the summerhouse. I'll probably be back in the library on Thursday and will look then for a new thread to discuss roofing materials eg toughened glass as in a conservatory (obviating the need for windows in the walls facing east and west) as against a well-insulated roof to retain heat rising from the underfloor heating. Fran

Hi Nickfromwales! If the northfacing slope is part of an equilateral triangle (0.5metre base, 0.5 metre vertically to apex) I suppose the pitch on the north face is 60 degrees. The southfacing slope is the hypoteneuse of a triangle with 1.5 metres base and 0.5 metre vertically to apex. Does 'how many m2' refer to the area of the southfacing slope?: that would be 5 metres wide and 1.57 metres from top to bottom of the slope. My next query is: does an inverter need its own power source to do its job? If so, I think I'll probably go for powering my underfloor heating from the mains (there's a charging point for Mum's mobility scooter about 3 metres from the proposed new summerhouse - I expect we can extend from there to power the summerhouse) rather than paying for a complicated roof, solar panels, inverter (and power source?), battery pack etc. So now I'm thinking in terms of a flat roof (5 metres by 3 metres), resting on the double skin breezeblock walls (with 4.5 metre run of patio doors facing south). What are the options for roofing materials? Perhaps I need to move into a different thread on this site to discuss roofing. I'm logging off in the library for today. When I visit the library again (probably next Wednesday) I'll check in this thread to see what further posts there have been, and look for a new thread. Fran

It sounds like the inverter can go behind the solar panels on the roof of my new summerhouse. The triangular shape of the non-flat-roof part of the summerhouse roof is 2 metres at the base with a 0.5 metre apex at 0.5 metre in. Will there be space for the inverter (and fan if it's inside the roof) in there? Will it need strong brackets to hold it up? (We intend for the inside of the summerhouse to be open to the apex of the roof (no false ceiling). I think I prefer the idea of the inverter being outside the structure of the summerhouse (without a fan). I imagine the output from the inverter will feed into a battery pack from which I can take power for underfloor heating (4.5 metres by 2.5 metres). Is there a website I can look at to get an idea of how much space inverter and battery pack will need? Fran

Hi ProDave! Thanks for your message. I'm guessing an inverter would look like a box (I'll be getting a professional to install it if that's the best route to go down). Would this box be outside the new summerhouse with the solar panels (5 metres by 1.57 metres approx) on the roof? Would it need to be in a waterproof 'cupboard', in the fashion of the external electricity meters some houses have outside? Fran

The Homelux Heatwave insulation board I saw on display in my local DIY store appears to have a core of pink polystyrene (1 centimetre thick) with a grey (fire-retardant?) skin to each face. Is there a more eco-friendly alternative, along the lines of shredded newspaper insulation? If so, would this need to be thicker than 1 centimetre? Fran

I Introduced myself on this site about half an hour ago (New summerhouse). I mentioned Tesla shingles versus solar panels. Perhaps this thread will help me choose. Fran

Hi, I haven't done Introducing myself as I haven't found out yet how to get to where I can type that in. We've pulled down a small summerhouse and would like to build a bigger one. My local authority website tells me I can go up to 5 metres by 3 metres without planning permission, and that the maximum height is 2.5 metres within 2 metres of a boundary and 3 metres beyond that. Our idea so far is: to leave a gap of 1 metre between the boundary (to the north) and the back of the summerhouse; have 1 metre of flat roof, then rise 0.5 metre for the next 0.5 metre (north-facing slope); then have a south-facing slope dropping 0.5 metre over the remaining 1.5 metre permitted depth of the building. We would like to fix solar panels or solar shingles (I found a reference to these at www.earthtechling.com/tesla-solar-panels-vs-rooftop-solar-panel ) to the south-facing slope and connect them to underfloor heating pads. I would like some advice about what material to use for the roof of this summerhouse if we want to fix solar panels to the south-facing slope (5 metres wide by about 1.57 metres top to bottom) or have solar shingles on this slope which would need to join at the apex with whatever the rest of the roof is made of. Signing up to the scheme for selling electricity to the grid finishes at the end of March, so we're not likely to take part in the scheme. We may not generate a lot of electricity anyway. I think it's possible to store electricity from solar panels for later use but haven't found out about this yet. We think we can build on a concrete base laid over the existing concreted area from 2 earlier sheds (but haven't checked on this yet) rather than digging foundations. On top of the base we aim to put a damp barrier (plastic sheeting) then build with a double skin of breezeblocks with a window in each side (facing east and west) and a run of south-facing patio doors (4.5 metres wide). Looking forward to hearing from others, Fran