There is such a large range of gas Fireplaces and electric Fireplaces in todays market, that there are plenty of options for homes without a chimney or flue.

Gas fireplace options available for homes without a chimney/ flue:

If the fireplace is going to be installed on an outside wall then you can have a Balanced Flue or Power Flue Gas fireplace. These types of Fires are specially designed to extract funes horizontally outside rather than up a chimney or flue. Alternatively you could source a modern Flueless gas fire which works using a catalytic converter. The cleaver internal mechanism within these types of Fires converts carbon monoxide into harmless carbon dioxide and water vapour. Flueless gas fires are approved for modern safety standards, however there is a minimum room size to meet the criteria needed (worked out as cubic square feet of oxygen in a room).

Electric fireplace options:

Electric fireplaces have become increasingly popular for their extreme flexibility, as they do not need any venting whatsoever. Electric fireplaces simply plug into a standard 13 amp socket, and can be fitted anywhere appropriate. Electric fires can also be used on flame effect only, without the need of having to turn the heater on.