I live in a small 2 bedroom end of terrace house. I have a Worcester 28Si Boiler in the corner of one of the bedrooms. I have been thinking about getting a joiner to box in the boiler for both aestetic reasons and also to reduce the noise the boiler makes (possibly lining a wooden built in cupboard with soundproofing material). My main issue is how much ventilation does the boiler need? In an ideal world I would like to have a completely sealed unit around the boiler so that I can reduce the noice the boiler makes in the room however I am aware that boilers need a certain amount of airflow. Saftey will always take priority over other things. If you can help advise it would be much appreciated. One option I have wodered about if it is required is cutting a hole in the ceiling and providing ventilation from the attic. Also assuming ventilation isn't an issue how much room should be left around the boiler.