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Loft Conversion: Do it yourself or hire a professional?

If you’re considering a loft conversion, are you planning on a DIY project or hiring a professional? Do you know where to start when converting a loft space?

These are some of the questions we’ll take a look at in this article.


Even if you ultimately decide to do the conversion on your own, it’s still a good idea to run your design by a professional such as an architect or a designer that have experience with loft conversions. They’ll be able to check your drawings for any problems and correct them before you begin the build.


Are you considering only using your loft space for additional storage? In that case, you can just board the space out. However, if you’d like to add windows and/or roof lights, then you’ll need to check for building regulations. It’s also a good idea to see if you need planning permission. You probably don’t, but it’s a good idea to check before starting your DIY loft conversion project.


If you’re planning to convert the loft into a room, then you’ll need to hire a professional. Why? Consider this: most lofts in the UK are not made to support the weight of a floor. The joists are not always strong enough to hold extra weight. In that case, the weight of the converted loft would lead to sagging.

When converting a loft into a room, you’ll need to install a structural floor. This means adding strong beams to support the floor and everything in the finished room.

If you decide to make this a DIY project, without expert knowledge, you could create a dangerous area, rather than a usable room. This is why it’s essential to hire a specialist with knowledge of loft conversions to work on the project, or at least to review your plans and design.


If you go ahead and do the loft conversion on your own, and the conversion doesn’t meet building regulations, then you won’t be able to count this as a room in a property description when you’d like to sell your home in the future.

In addition, if the conversion doesn’t meet building regulations and hasn’t been approved by a building inspector, potential buyers will think twice before buying the property. And if the converted space is an eyesore, you’ll drive potential buyers off right away. 

Again, hiring a professional who has specialized knowledge of loft conversions is the way to go. While this is an added expense, it will save you money in the long run. Your new room will meet the codes and be a beautiful addition that adds value to your property.


One of the first things you’ll need to do is to go to the loft and measure the head height. Head clearance must be over 2.1m for any loft conversion project. To measure the head height, you’ll need to measure from the top of the existing ceiling joist to the underside of the existing ridge board (the board placed along the top of the roof—the upper ends of the rafters are fastened to it).

In addition, you’ll want to check the pitch of your roof—to do this, measure the angle of the roof. Keep in mind that the higher the pitch angle, the higher the central head height will be.

And be sure to measure the loft’s footprint. The internal measurements should come be at least 5500mm from side to side (including the chimney), and 7500mm front to back.

When you have all the measurements completed, then you’ll need to consider how you plan on using the space. Will it be used as a bedroom with an en suite bathroom? Or do you plan on using it as a den or a playroom for the kids?

As you consider the room’s use, remember to consider the storage you may want. Under eave areas are difficult to fit with store-bought storage options. You may want to consider opting instead for bespoke storage options.


If you choose to hire a professional, how do you choose the best quote? When it comes to loft conversion quotes, there’s the tendency to either go with the cheapest quote received, or to go with the most expensive quote. By going with the cheapest quote, you may end up hiring someone who doesn’t really know what they’re doing. You’ll be faced with problems, extra costs and could even end up spending more in the long run.

However, going with the highest quote can also be a problem. Some people believe that the guy with the highest quote offers better services. This simply isn’t always the case.

You want to find a professional specialist who has the knowledge and experience needed for your unique loft conversion. This means doing research to find specialists, checking their credentials and referrals (actually contacting their referrals directly), checking for reviews online, etc. Once you have at least 3-4 builders (or more) on your list, then you can go ahead and ask for quotes. Choose the builder who has the experience and knowledge, rather than only basing your choice on their quote.

OK—you have this information, now let’s take a look at some of the cheaper types of DIY loft conversions you can do!


These are usually the simplest type of loft conversion for a DIY project. For this project, Velux windows are installed between existing rafters in the sloped roof and you don’t have to make any changes to the roofline.

You’ll need to make sure the ridge line is high enough to ensure you’ll have enough head room. It will also help ensure you can make good use of the floor space in the loft.

While Velux is usually cheap to install, this type of loft conversion does not result in as much usable space as conversions that are done with added dormers.

A Velux loft conversion, without an added bathroom or roof work with cost:

  • Terraced home: will cost about £30,000
  • Semi-detached or detached home: will cost about £50,000

If you need to add a new roof, then count on it costing about an additional £5,000 to £25,000. The cost will depend on the size of your property and the type of roof tile used.


The other cheapest type of loft conversion is installing a flat roofed dormer on the back of the house. Here, you want to avoid the conversion looking as if it’s just slapped on. This can not only look badly but can lower the value of your home.

The cost of this type of loft conversion runs about £35,000 if you have a smaller home terraced home. If you have a semi-detached or a detached home, expect to pay about £45,000 for the loft conversion. These costs will increase if you decide to add on a bathroom, walls, plumbing, etc.


If you just don’t have the funds to hire a professional and you don’t want to take on the project yourself, then the best option is to wait. This is a big project and a large investment in your property. You want it done right. So, you might consider doing another type of home project or save up the money to hire a professional.

Written By
ecoTrus Manager
May 10, 2023