Roof replacement prices in US range from $. $. per sq.ft. for asphalt shingles to $. $. per sq.ft. for metal wood, etc . Your actual cost will vary depending on roof size compl.See how much it costs to replace a flat roof in the UK with our recently updated price guide. Also, get your own custom quote today..How much does a replacement conservatory roof cost compared with getting and new one? Well, the answer might both shock and please you..HomeAdvisor’s Roofing Cost Guide lists pricesociated with installing a new roof including labor and materials, as reported by HomeAdvisor customers..