Devon is a wet place. External timber suffers. Sometimes it needs replacement, sometimes repair. This roof was letting in water and the timbers rotten, so replacement with new chestnut purlins. We had just finished for the day and got it covered, when the first raindrops fell. Useful for the next morning, to be able to keep working, under. Hail tarpaulins!
Here's one we fixed earlier. This box sash was about as bad as it gets before complete replacement is necessary. We always try to save as much historic fabric as possible. This window (and wall it is in) has always been up against it, the ground outside is 4ft up the side of the house. The wall/window have to deal with penetrating damp AND runoff from the concrete ground surface outside. It's not possible to lower the ground level as it's public. We replaced the cill, half the inner face of the boxes and the cheeks. A new sash, added a lb. or two to the weights, new cords and brushed parting beads. Re-purried other sash and painted. Removed silicon and sealed around frame with lime mortar. Similar to next window. Proper job.
Look after the pennies and the pounds will take care of themselves. Every small part of a building should be well maintained to protect the whole thing and preserve it for posterity. Replacement door cill and scarfed in jamb ends, in oak.
Replace where necessary. Otherwise repair. Protect historic fabric. Protect tradesman protecting historic fabric.........with tarpaulins. A dry tradesman is a happy tradesman! Hail tarpaulins. Amen.