Paint the walls in there flat white for reflection.
Hello Marijuanga91,
I am also a Brit and, sadly, the Police seem to have returned to paying considerable attention to small time growers.
They're even posting a 'scratch and sniff' card around certain areas so people can familiarise themselves with the aroma of growing plants.
You'd think they'd have better things to be getting on with (like tackling crimes With ACTUAL victims) but, there you go.
I would buy some sheets of reflective mylar. Silver diamond stuff is very effective and inexpensive from several e-bay sellers.
It will not cost much more than the price of painting your space white - and it will be far more reflective (thus far more effective).
Ventilation: Fan and filter.
This is worth buying just for the peace of mind that it will bring you during flowering season.
The alternative is one hell of an obvious stink that makes you an easy target for Police or bad men who know you can't call the cops to report some home invaders have stolen your home grown cannabis.
But that's not even half the benefit of good ventilation.
Humidity can be a problem and the only thing that prevents it is good ventilation.
High temperatures are also an issue that good ventilation combats.
Seriously, mate.
Sort out your ventilation situation before buds form and announce they're arrival with uncontrollable amounts of highly distinctive odour.
PM me and I'll send you a link that tells you how to work out the best sized fans and filters for your particular growing space.
PS - don't believe the Grow Shops when they say that 1.2 x 1.2 m spaces need only 4'' fans.
It's bullshit and you'll need a bigger fan before the end of our second month of growing.
Buy the right equipment first time and do not fall for the false economy of very small fans.