Loft Conversion Costs

Cost estimates and information on loft conversions

To convert the space you have in your loft is perhaps the cheapest option for adding extra living space to your home. They are not suitable for all types of property but the extra space can have many different uses. Let's look at what some of the issues and how the costs involved add up.

Skip to our prices 

Planning permission

In many cases if the loft conversion doesn't add to the volume of the house (that is extend it upwards or outwards) then you probably won't need planning permission . If in doubt, as always talk to your builder and/or local planning office. There are circumstances in which you will almost certainly need planning permission

As with conservatories and normal house extensions you can add to your property without planning permission if the volume of the additional space is less than a given amount. As of Nov 2007 you cannot add more than

The volume constraints are based upon the external dimension of the conversion you are planning. 

Even if you do not need to seek planning permission (but be careful getting permission retrospectively is tricky..) then the modification to the property will need to comply with building regulations for loft conversions.

Building Regulations 

The main aim of these is to ensure that the property is still safe for the occupants after the conversion has been adding. In summary this includes

If the loft conversion is going into a 3 storey building then the rules are similar but stricter.

Types of Conversion

Time Taken

Obviously varies with the size and complexity of the project but one could expect it to take between 4-12 weeks to complete, not including any planning permission etc (if required). 

Loft Conversion Prices

Unless otherwise stated these prices are valid as of Nov 2007. 

The table below shows the latest average prices we have and also the range of prices we have received on loft conversions. To see more details on the specifics try clicking on the link on the left hand side which will take you to a page with more details on the category. 

Loft Conversion Prices: Disclaimer
Category Average Cost Price Range Units Last Updated
£24200 £5800-35000 per item/job 2013-04-23
Plans £1250 £500-2000 per item/job 2007-11-13
Self-build £14000 £4000-24000 per item/job 2010-02-26
Self-build £307 £307 per m2 2007-10-01
Staircase £2545 £700-11000 per item/job 2010-03-20
Whole project £24215 £25-68000 per item/job 2015-07-23
Whole project £789 £425-1600 per m2 2014-04-12
Windows £6852 £150-26000 per item/job 2011-05-10
£1260 £1260 per private 2011-10-01
Wiring £1276 £728-2075 per item/job 2011-02-11

This is NOT a form for requesting quotes. Please use this instead if you desire a quote for work

Please tell us your own prices

Loft Conversion Uses 

"Hi, you need to keep your prices up to date (Jan 2014), local authority planing permission is now £172 (full plans) and Building Regs/Inspection £532"

SJSBuilding london

"good site will come back to it when thinking clears"


"Very glad i found this page so i can be more confident when talking to people who'll do a quote for me, thanks"

S Brown

"great page very useful"

roy baker

"well written and practical thank you"


"Very useful - thank you. I have had a couple of very different quotes but the cheapest is spot on your £605 per metre so I feel reassured. I will input my project when completed"


"Very useful - thanks."


"very informative, especially the price per metre squared. thanks "


"I found it very useful, thanks"


"WOW! That is a lot of money...we were thinking ether a loft coversion or a log cabin at the end of the garden for my 18 year old son.I think we are going to go for the log cabin though because thats around £3500."