How much does it cost to convert a loft into a bedroom?
Christopher Pierce
Updated on February 28, 2026
A loft conversion costs $7,000 to $67,600, averaging about $20,000. This translates into a price of $50 to $150 per square foot. You’ll pay $9,000 to $34,500 to build a loft from scratch, and $14,300 to $67,600 to turn an existing one into a bedroom with ensuite bathroom.
How much does a loft conversion cost roughly?
General Labour Costs and Timescales Based On Conversion Type
| Type of Conversion | Duration | Average cost |
|---|---|---|
| Velux Loft Conversion | 4-6 weeks | £9,000-£14,000 |
| Dormer Loft Conversion | 6-8 weeks | £20,000-£40,000 |
| Hip-to-Gable Loft Conversion | 6-8 weeks | £20,000-£35,000 |
| Mansard Loft Conversion | 8-10 weeks | £25,000-£45,000 |
How much does it cost to convert a loft into a room UK?
A loft conversion typically costs between £21,000 – £44,000. You could pay up to £63,000 if you want a particularly large extension. The biggest factors that affect price are the size of the extension, your location, and the number of dormers.
Can you put a bathroom in a loft conversion?
Converting your loft into a master bathroom can be a great idea as it should give you much more room to play with. The unconventional space and sloping roof make it the ideal place to add a freestanding bath. A window built into the sloping roof is the best option to maintain privacy.
Do you need planning permission to put a bathroom in a loft?
Though you’ll still need to satisfy building regulations, most loft conversion projects don’t require any planning permission. There’s a short list of conditions your conversion will have to meet before you go ahead, so it’s worth discussing your plans with a builder before you start to make absolutely sure.
How much does it cost to convert a loft to a bathroom?
A full loft conversion can add up to 20% to a property’s value in London. In this example, a large master bedroom in the loft might add 15% to the value of your home, and an ensuite bathroom 5%.
Where do you put stairs in a loft conversion?
When it comes to loft conversions, however, staircase headroom can be 1.8m to the side of a stair, and 1.9m in the centre. The highest part of the loft, in line with the roof ridge, is an ideal location for a staircase to land, therefore.
