I found this spider in my house today and I have never seen one like it! It's about a good inch long and all brown. It has like little bits on it's back...possible a weaver. It is fast but was also little aggressive when caught it as it was on the curtain.
Any chance we could have a shot from directly above (dorsal view)? It could well be a sac spider (Clubiona species), or a stone spider (Drassodes species). Either way, it doesn't look unusual for UK spider. They hunt on the run, so are quick & on the aggressive side.