How Much Does A Loft Conversion Cost?

  • Find out the average cost of converting your loft space.
  • Ideas for your new loft conversion.

Too long have the loft spaces of houses been used for nothing but storing the ever-growing collection of holiday decorations.

Budgeting for your loft conversion

Converting the loft of your home isn’t quite like re-fitting any other room of the house. It’s very unlikely that the house you currently reside in has had any work done on the loft. In fact, it’s probably a dusty, old storage space with yellowed insulation that’s very visible.

If we’ve just described the space within your home’s roof, which is only accessible by ladder, and is only seen twice a year – once to retrieve the holiday decorations, and a second time to put them back – then you’ve found yourself in the right place.

Before starting your loft conversion, or, really, doing any work to it at all, you should aim to save up enough to see the conversion all the way through to the end.

A loft conversion can cost anywhere from £20,000 to £60,000 (approximately), depending on what you actually want to do with your loft space.

It’s not a small job, and it will feel like a financial hole in your wallet until the conversion has been completed and you can see the fruits of your labour right in front of you.

Conversion types and costs

There are four main types of loft conversion, with each raising the price of your conversion plans as the roof conversion becomes more complex.


The velux conversion is the most affordable. You can have this type of loft conversion completed for around £20,000 to £40,000. It is a simple conversion that involves adding just one or two windows into the roof of your home to bring in natural light into the space.

A loft conversion with added windows.


The most common type of loft conversion known as the dormer, is a small and flat roofed extension with an added window. When looking for this type of conversion, you’ll likely notice that homeowners prefer to have two dormer windows rather than one, just for symmetry.

Cost-wise, you could be looking at anything from £30,000 to £60,000, depending on the type of dormer. The most expensive there being an L-shaped dormer.

Hip to Gable

The sloping parts of your home’s roof are changed out for a gable wall. This can be on both ends of the roof or just one. Approximate cost for this loft conversion ranges from £40,000 to £65,000.

See Also


To have a mansard extension, you would need to replace an entire side of your home’s roof. Instead of your old roof, you would have a straight wall with a flat roof, which can then be extended on both sides and may end in your home gaining a new level. It’s a big project, costing up to £75,000.

Other costs

The costs outlined above are for the conversion of your home’s roof and the addition of windows and roof extensions. None of this takes into account any furnishings or decoration that you may want to add into the room that is your loft.

A loft that has been converted into a double bedroom.

Do you need planning permission for a loft conversion?

This entirely depends on the type of conversion that you’re going for. If the conversion will alter the current roof of your home by extending the height, you need to inform the planning department of your local council and check you can start the conversion.

In addition, if the conversion will alter the view that your neighbours have, you must inform your local planning authority of your conversion plans. Once you do this, your neighbours have 21 days to object to your conversion plans before you gain full permission to begin your plans.

Will a loft conversion increase your property price?

Usually, yes, it will. A loft conversion that has become a bedroom has the potential to add around 20% value onto your home. They’re a good investment if you have the finances and the time to see the conversion through to the end.

© 2022 All Rights Reserved.