Cost Of Second Floor Extension. A second storey addition can cost between 1850 and 3300 per square metre depending on the quality and price of construction materials and inclusions and if your ground floor foundations need reinforcing to carry the load of the extension. As of last year the estimated cost of a single-storey extension outside of London fell anywhere between 1200 and 1500 per metre square.
This includes framing out the house extension and interior finishes with mid-range materials. Adding a ground-floor extension definitely isnt cheap but the complexity of a second floor contributes to its generally higher cost. Overall Cost of an Extension.
Adding a ground-floor extension definitely isnt cheap but the complexity of a second floor contributes to its generally higher cost.
32 degrees building specialise in first floor addition or second storey extensions. Average costs and comments from CostHelpers team of professional journalists and community of users. Single storey house extension cost. Once the extension is built fitting a bathroom could cost around 3500.
