Dan Smithers writes
Currently I have two greenhouses each 8' x 6' next to each other.

One is cold and I keep the other frost free (or just above).

I am considering whether to replace them with one large house say 14' x 9'.

This way I could heat the whole space.

Or you could divide it with a 'wall' of bubble foam and heat part of it.
Or you could have an internal glass partition.

Would I get more in a large house
than two small?

8 x 6 =48 sq ft = 96 sq ft in total, 14 x 9 = 126 sq ft so in theory,
yes. But you won't want your beds or staging much above 30 inches, so
you'll have a bigger empty space in the centre of the 9ft greenhouse.
(Or you could have narrower staging and free-standing things in the
middle).

But, against that, the bigger space will be much more flexible, so
you'll make better use of it.. And the ceiling height will be greater.

Big advantage of bigger greenhouse is temperature stability - it won't
lose heat so fast in winter and it won't overheat so rapidly in summer.

They are standing on a hard base and I put grow bags in for tomatoes etc
in the summer and have staging on one side.

I would also like to have a greenhouse vine.

Having permanent plants in a greenhouse makes pest control more
difficult. Less easy yo empty it out completely, and you can't fumigate
with anything that's unfriendly to plants.

If you do get anything (eg aphids) on the vine, you'll find you get
black mould on any plants that are too closely crowded underneath.
Therefore, you'll need to keep the vine well in check so as not to
overwhelm the other plants.

The plus side is that the vine will give shade in the summer (don't know
how it copes with the heat itself) but will lose its leaves to let light
in in the winter.


--
Kay