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The perfect greenhouse/conservatory

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Dear all, I guess many of you have experience over the years of the best method to grow certain species.  I have an opportunity to start from scratch and in an ideal world would build an attractive greenhouse/conservatory that has drainage and heating to suit tropical plants especially carnivorous species (+ tropical cacti), as well as a cooler frost free section and more standard coldframe/cold house attached for other species such as saracenias.  For those of you that know Winterbourne I am thinking along the lines of  a smaller version of their tropical house/their cacti house and CPS display.

 

I can work on the design but my key question is what heating system would you recommend for the main tropical section or frost free section? I am envisaging a brick base glazed structure. Would like to keep heating bills down.

 

If anyone can recommend and greenhouse suppliers, have designs that they have used and like, Id be grateful for that information too.

Andy

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I got an 18x10ft with three sections (two internal partitions) last year, very pleased with it so far, from Woodpecker joinery in Staffordshire, they do bespoke designs, benches, cold frames etc.

A large part of our cost was actually having the garden flattened and a decent base putting in. We had a brick/ concrete base, to help level the ground more than anything.

Couple of things that worked out really well;

We had two inches of polystyrene insulation put in the base and concrete put on top, pretty much like a garage base these days. The insulation and concrete act as a heat resevoir, so in mid summer at 5am in the morning, the greenhouse is still several degrees warmer than outside.

The only slight issue with the concrete is it was put in very smooth, great job by the builders, but can get a bit slippy in the summer when algae grows in it, not a major problem but i did slip once and damaged my knee...

The glazing is toughened glass with 25mm polycarbonate inside the glass, heating bills were very low. The light is about equivalent to 40% shading, good enough for neps, and many sundews / pinguiculas / orchids. Some sundews/drosophyllum do better outside in more sun, but i could easily have taken out a section of polycarb for the summer, just didnt bother.

All our greenhouse heating is electric, it has some advantages, easier to control, no need for ventilation. I use very cheap electric fan heaters. Thinking of switching to tubular heaters as i can hide those under the bench (and theyre splash proof).

If your prone to power cuts a backup lpg heater might be a good option.

Our coldest section we put near the external door, the aim was to keep it just frost free, what we found was there was enough heat leaking in from the mddle section that i dont think the heater ever switched on in the cold section (last year - mild winter). Hottest section is at the far end.

I did consider heating with a heat pump but our heating costs are so low its not worth thinking about. Equally cost of installing a gas line isn't probably worth it, LPG might be an option but i'm too lazy to change bottles...

At the moment i cant think of anything I would change on the greenhouse. If its a conservatory attached to a house then heating by gas via the central heating system is an easy option and thats how our conservatory is heated.

We are considering a slightly bonkers scheme to put a conservatory over the attached garage, if we do, it will probably be triple glazed (U value ~0.9) and heated by the central heating system with electric for backup. Should give us another 200sqft of growing space!

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Forgot one thing! Try and get a decent eaves height, 6ft or better, it really does make a difference! Also i just had a quick look at the greenhouse photos at winterbourne and they look very similar (if not the same!) as those produced by woodpecker joinery.

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I got an 18x10ft with three sections (two internal partitions) last year, very pleased with it so far, from Woodpecker joinery in Staffordshire, they do bespoke designs, benches, cold frames etc.

A large part of our cost was actually having the garden flattened and a decent base putting in. We had a brick/ concrete base, to help level the ground more than anything.

Couple of things that worked out really well;

We had two inches of polystyrene insulation put in the base and concrete put on top, pretty much like a garage base these days. The insulation and concrete act as a heat resevoir, so in mid summer at 5am in the morning, the greenhouse is still several degrees warmer than outside.

The only slight issue with the concrete is it was put in very smooth, great job by the builders, but can get a bit slippy in the summer when algae grows in it, not a major problem but i did slip once and damaged my knee...

The glazing is toughened glass with 25mm polycarbonate inside the glass, heating bills were very low. The light is about equivalent to 40% shading, good enough for neps, and many sundews / pinguiculas / orchids. Some sundews/drosophyllum do better outside in more sun, but i could easily have taken out a section of polycarb for the summer, just didnt bother.

All our greenhouse heating is electric, it has some advantages, easier to control, no need for ventilation. I use very cheap electric fan heaters. Thinking of switching to tubular heaters as i can hide those under the bench (and theyre splash proof).

If your prone to power cuts a backup lpg heater might be a good option.

Our coldest section we put near the external door, the aim was to keep it just frost free, what we found was there was enough heat leaking in from the mddle section that i dont think the heater ever switched on in the cold section (last year - mild winter). Hottest section is at the far end.

I did consider heating with a heat pump but our heating costs are so low its not worth thinking about. Equally cost of installing a gas line isn't probably worth it, LPG might be an option but i'm too lazy to change bottles...

At the moment i cant think of anything I would change on the greenhouse. If its a conservatory attached to a house then heating by gas via the central heating system is an easy option and thats how our conservatory is heated.

We are considering a slightly bonkers scheme to put a conservatory over the attached garage, if we do, it will probably be triple glazed (U value ~0.9) and heated by the central heating system with electric for backup. Should give us another 200sqft of growing space!

That's really useful information, thank you.  I cant wait to move into the property and start planning! Thankfully the site is level.  Good point about power cuts too, where I live currently they happen about once a month.  I like the idea of the polystyrene concrete base. Did you need planning permission for the greenhouse? Andy

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Normally you dont need planning permission, as long as the greenhouse is less than 50% of the garden area and is less than 4m tall. If its within 2 metres of the boundary then it has to be less than 2.5m tall.

The numbers are from memory, so double check! But basically thats the gist of it.

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Normally you dont need planning permission, as long as the greenhouse is less than 50% of the garden area and is less than 4m tall. If its within 2 metres of the boundary then it has to be less than 2.5m tall.

The numbers are from memory, so double check! But basically thats the gist of it.

Thank you!

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You don't say whether it will be free standing or attached to the house.

 

If it's attached to the house, that should greatly reduce the need to heat it.

 

Good luck with the project, it sounds like it will be fantastic.

Do keep us updated with progress pics.

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You don't say whether it will be free standing or attached to the house.

 

If it's attached to the house, that should greatly reduce the need to heat it.

 

Good luck with the project, it sounds like it will be fantastic.

Do keep us updated with progress pics.

Thanks Phil - that's part of the planning. There is the possibility of attaching it to the house, but its an awkward shape and would entail moving the entrance or having the entrance via the greenhouse!  Id love that, but most visitors and postmen would think it odd , so free standing may be easier, but as you suggest more expensive to heat.  Thanks again.

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