Yes, compost would improve the soil in a number of ways.

Its an expensive way of doing it though. Anything you can add which will improve the texture will help, garden compost, rotted leaf litter, rotted manure etc. If you have a lawn you can use the mowings as a mulch, or leave them in a heap to rot down if you have room. Don't worry about adding stuff that hasn't finished rotting - it may well deplete the nitrogen for a while but you can add that later.
Its good to hear someone is removing membrane -more power to your elbow!

You might also sow some green manure as you clear the space, and dig it in before it seeds.

Better to use composted animal manure (sold at the garden centre) or your own garden compost (if you have any), leafmould, spent mushroom compost, anything like that rather than multi purpose potting compost, as Steragram intimates.

what other kind is there?

Seed sowing compost, ericaceous compost, cactus compost, John Innes soil based compost etc.

In my case, I would let it sit out and let the birds help themselves to the seeds for a few days. Stera - who wants to grow cactus, in Kent?

If as you say, you're concerned that weeds will grow in the shingle, I would rake it over occasionally so the the sun dries out anything that germinates. Then the problem with the soil underneath. You say that there is only a couple of inches of soil above chalk then I would tackle a small area at a time. I would try to remove some of the chalk or raise the level of your garden and break up the subsoil (chalk). Don't waste you time with composts, have a large builder's bag of top soil delivered at a time. At the end of the day you will only be able to grow lime-lovers which are fairly drought resistant.

Yes, there is something you can use to kill the weeds, if you don't want to do what Jimmytheone suggests - Pathclear. Needs mixing in a watering can or sprayer and watering on, do it in April or May, when weeds are growing fairly strongly, and it should last 3-5 months. There's another product made by Bayer called Groundclear which is good, and it doesn't sound as if there's any planted areas there, but if you've got any planting, best not use that one. Treat the whole area, regardless whether there's weed growth or not - both contain a residual weedkiller that discourages weed germination.

Sounds like you're going to have to use large pots and put some plants in those. As for responding or saying thanks, scroll down beneath the last answer and click in the empty box - it expands and you can add something in there.

Lol Bathgate, only optimists! I was just answering you by listing compost types, not suggesting what Nanajen might put in her garden...

Well, Steragram, I do know someone who uses cactus compost in Orpington, actually - my brother's got a collection of cactus in his conservatory... prickly place to sit, I must say, not keen myself, but each to his own.

Stera - Sorry for playing 'devil's advocate.' I was just teasing you a little. Actually, cactus compost would be better then what's there now. Chalk! There are plants that thrive in very poor soil. To name a few, you might consider Lenten Rose, Vinca Minor (periwinkle), Bleeding Hearts, Gaillardia Fanfare, Black Jack Sedum or Oregano Grape.

Furthermore, I would caution you against using weed killers & herbicides like Pathclear, Groundclear and such like. Sure they seem like a quick & obvious solution, but the harsh chemicals in these products contaminate the ground and cause tremendous damage to the environment and unintended consequences. 'Run off & drift' can kill the "good plants." The plants I mentioned above will not survive even minute traces of these chemicals. They kill/damage beneficial microbes & organisms: worms, frogs, birds, other living things. Breathing in vapors or drift cannot be good for your health either - your dog? The bees? What about my little lizards I have living in my garden? That stuff will kill them and wipe out their food supply. I enjoy having them and want to keep them.

Thanks folks for all suggestions. Now have ordered some lovely Redwood Railway sleepers to do a raised border by the front wall so I can plant my rose hedge Queen Elizabeth, when it arrives, replaced new membrane under gravel and bought some very nice pots, so shrubs will be going in those, starting off with smaller pots, then into larger when ready. After speaking to some neighbors found out that chalk is very dense in this area, that is why so many bungalows have hard landscaping, I suppose to be expected when about 1/2 mile from the Bay, which is chalk cliffs.

Sounds like you have a plan. Good luck to you.

Once again peoples Thank you very much for your input!!!