The average cost of a loft conversion in the UK is £30,000 for a conversion consisting of two bedrooms, one bathroom and one dormer extension.
How much does a loft conversion cost?
Although the above is an average loft conversion cost for the UK, lofts do vary in their dimensions and existing specification and there are a couple of variables which will determine your total loft conversion cost.
The key factor which can increase your loft conversion cost is whether you decide to opt for a loft extension as well as loft conversion.
A loft conversion with a couple of Velux windows and no major alterations or extensions to your existing roof will usually cost in the region of £20,000.
If you are looking to maximise the potential floor area of your loft conversion then extending your external walls upwards and altering one side of your roof into a mansard style roof is a popular option. A loft conversion with a mansard roof extension usually costs in the region of £35,000.
A lower cost alternative, whilst still maximising on floor area, is to build a dormer extension which is smaller than a mansard extension and usually costs in the region of £25,000.
Layout and fixtures
Your requirements for how you will use your new loft space will also play a role in your loft conversion cost. For example, a bathroom installation will require all of your plumbing and waste services to be extended, and depending upon the existing position of these services, the amount of work involved can vary. On average, a loft bathroom installation usually costs in the region of £6,000.
The cost of all other furniture and fixtures is entirely ruled by your budget. You can easily spend £30,000 on new designer furniture and fixtures, or you can spend £3,000 for cheaper high-street equivalents. Hence, it is hard to provide an average cost for these elements of a loft conversion.
Finally, the height of your existing roof is crucial in determining the feasibility of your loft conversion and its cost. If the existing height of your roof is significantly under 2.4 metres, and you have no other viable option of extending your home’s liveable area other than with a loft conversion, you will most likely need a new roof with a greater ridge height, planning permission permitting. The cost of a new roof usually starts from £8,000 on a modest-sized home and can increase to over £30,000 on a large detached home.