new shed base

My builder said "about" £500 for a larger footprint, plus time (160 ish)

It should say £20 per hour. ?

Sounds like you have your shed.

Base doesn’t need to be thick. It depends on what’s happening in the shed. Our last shed has a large lathe in it so we had a thicker bed laid.
Concrete hasn’t gone up much over past year. We buy it regularly (new build). 72p increase per bag since a year ago. Supplies are short due to increase in construction business. We’ve been limited to 10 bags per order. Same thing with wood. Demand is out stripping supply. Very little shuttering boarding needed for that size.

Labour cost should not be higher than £20. I paid £15 ph for new raised beds and pavers laid.

Shed base that size could be done easily in one day.

Good luck with the quotes.

Have you found a shed with a reasonable delivery time on it yet travelsafar? If not, I would look now and get one ordered, before you have the base laid. Finding what you want is a real problem I’ve found, and it’s getting worse as supplier stocks run out. I want a potting shed, but my choice has a 40 week delivery!

Did you get a breakdown of the costings.
Materials, man hours/labour and VAT to compare to other quotes?

I’ve honestly got no idea how long this type of job would take.
I guess it depends on how much preparation is needed, digging out, levelling, waiting for cement to go off etc…

You may not need a deep concrete base anyway. Slabs, as faringdon59 said above, or an interlocking grid shed base with gravel infill, may be easier and far cheaper.

Yes, prices for anything to do with garden work, sheds have shot up this year.
I bought a shed at sale price back in April. Called my youngest son who is a builder to ask if he could put up for me, he said yes. I had it delivered, he got crazy busy and my shed job got put back.
So, I got quotes and it all looked very OTT to me.
Then I thought about asking my window cleaner (who seems very practical) if he would give me a quote.
We used slabs from another part of the garden to form the base and then he constructed from there.
She now looking good and last weekend I put some wire mesh around the bottom in order to vermin proof it (hopefully!)
But my son has explained that there has been an unprecedented increase in the price of materials (doubling in some cases) and some much in short supply.

Sounds expensive but I know building material prices have rocketed and some are in very short supply. All down to Brexit apparently.

Sounds a bit steep to me travels. You’ll get a better idea with more quotes.