Sometimes, but it should never be assumed. It depends on the boiler’s output, how much spare capacity the current system has, and the size and glazing of the new space. We would rather work that out at the design stage than have you discover after the plaster is on that the boiler cannot keep up. If it can cope, we will say so and save you the cost of changing it.

Usually yes. The two things that decide how straightforward it is are the pipe route from the existing system up to the new floor, and whether the boiler and pump can push heat that far without robbing the rooms below. Loft rooms also behave differently from the rest of the house thermally, so they often need a different radiator size than you would expect for the floor area.

Both are valid, and which is right depends on the system. Older radiators are frequently undersized for the way a room is used now, especially in a knocked-through kitchen-diner. Sometimes swapping a couple of key radiators for a modern equivalent solves it; sometimes the system needs rebalancing so heat stops going where it is not needed. We will measure rather than guess.

For a straightforward like-for-like swap in a standard-layout semi it is often a single day. It takes longer if the boiler is moving position, if the flue route changes, or if the system needs flushing and new controls at the same time. We will tell you which of those applies before the day so you can plan around being without heating and hot water.

Yes — we cover S8 and the surrounding parts of south Sheffield, including Norton Lees, Meersbrook, Beauchief, Abbeydale, Norton and Greenhill. Give us a call if you are close by and unsure and we will confirm straight away.