Is a Loft Conversion Cheaper Than an Extension?

By Jon Pritchard In Home improvement, Loft conversion 1 Comment

A show currently airing on Channel 4: Sarah Beeny’s Double your House for Half the Money, demonstrates the thirst that we all have for extending our homes as the property market heats up. It’s definitely a sensible option when compared to moving home as we’ve covered in a previous blog.

There are a number of options for extending your home and creating valuable extra floor space such as basement conversions and single story rear extensions, but loft conversions tend to be the most cost effective.

Loft Conversions

Pretty much anyone with a loft can have a loft conversion and because the shell structure is already in situ it’s a case of alteration rather than starting the build from scratch.

This reduces costs because there is less structural work when compared with other builds, moreover planning consent may not be necessary. With an extension for example, by taking away a load bearing wall you will need to install a steel beam or lintel, which tend to be quite expensive, and you will pretty much always need to seek permission.

Design-wise, of course, you’re quite free with a loft conversion but you probably wouldn’t want to put a dining room up there as entertaining spaces are best on the ground floor, of course. For some purposes though, being above the main house has its advantages, like if you’re creating a studio annex or ‘granny flat’ as they’re otherwise known.

Overall loft conversions are great value and give you a wide range of build and design options.

Cost: 10

Design: 8

Suitability: 8


Extensions are undoubtedly a good way of creating space and can be split over two levels, which is a bonus. Of course if it’s extra kitchen space you’re after you won’t have a loft conversion but a rear extension will take up garden space meaning that your patio area could end up feeling a little cramped.

Extensions are more costly than loft conversions but pip them in terms of design possibilities.

Remember to factor in the cost of wiring and heating when considering this type of build. It is often overlooked as an essential cost and is pricier than installation in lofts.

Cost: 7

Design: 9

Suitability: 8

Basement Conversions

There’s no getting away from it, a basement conversion is a big job. The equipment to dig it out looks like something from a quarry or a coal mine but they can look stunning upon completion.

The complexity of the build means that they aren’t cheap either, indeed they’re the most expensive of the three but for some, such as those living in garden flats or if you’re a space upgrading junkie and have already had a loft conversion and extension, they’re a solid option.

When budgeting add on a small buffer to the total cost because basement conversions can be tricky. Indeed, wealthy homeowners in London are buying JCBs and burying them in the basement itself because it’s cheaper and easier than excavating it once the build is complete.

Also remember that you might be restricted in terms of getting natural light in, not at all a problem for extensions or professionally done loft conversions.

Cost: 6

Design: 6

Suitability: 5

So in answer to the question which is the title of this blog, yes loft conversions are cheaper than extensions. However, it’s probably best not to go with the cheapest option just because, homeowners should always prioritise use value over price. Sure, you can have a loft conversion but if what you really need is more space downstairs it’s probably not the best option. Because above all creating the feeling of space alone is no guarantee that your home will work better, or that the extra space will get used, so do think carefully about your lifestyle and fit your design requirements around that.

If this happens to be a loft conversion and you save a bit of money in a process that’s a bonus!