Can anyone recommend good loft conversion company?

We live in a standard 90’s detached 3 bed bungalow 100 square metres and our family has now grown to 5. We are based in Sallins/Naas Kildare.

At this stage we don’t want to move so figured the best thing to do would be to do a rear dormer loft conversion.

We need a bedroom, bathroom and storage up there. The hall way is quite wide downstairs so should take a stairs handily.

We have 2.5 metres of height in the attic( naturally we will loose a good chunk of it in the flooring etc so will likely have 2.1 to 2.2 head roomif we are lucky)

We are nervous to proceed given our experiences with builders has been poor any time we get work done in the house.

Has anyone recently done this and do they have recommendations and even what it cost you would be great?