I've never made it less than 14kg and I aim for 15kg, usually come in at 17kg.
Basics are Hike Like Pro Tent or DD tarp, Alpkit Pipedream 600, self inflating mat (soon to be 3/4 length), Alpkit bivy bag, trangia mini+food+meths, Sigg+at least 1L water, some spare clothes. However, once I pack that all up with odds and ends I I usually end up at 16ish. I'm a big carnivore and always take too much meat and it's suprisingly heavy.
Also, I have a Vango 50L rucksack which is nearly 2Kg. If I could lighten that it would help considerably.