How to Do a Loft Conversion

Tips & Advice
how to
wood panelled bedroom in converted loft with several velux windows

If you’d like to breathe new life into your home, nothing beats adding square metres of usable living space. Whether yours will become a spare bedroom, a home office, or even a gym, converting your loft won’t just give you and your family more room to live, it can even add significant value to your home when it’s time to sell.

The loft is an underutilised part of most British homes and can make for the perfect home improvement project. Below, we’re going to talk you through the major steps involved when doing a loft conversion, to help you create the welcoming living space you deserve.

Table of Contents

Can Your Loft Be Converted?

The first question you’ll need to ask yourself is whether or not your loft can be converted.

First and foremost, a loft conversion will always add extra weight to your property. You will need to double-check that the structure of your property can handle this. This means exposing the foundations along with any beams, lintels, and other structural components that may be required to carry an increased load. This is often the first hurdle that loft conversion projects encounter, as extra underpinning can almost double the cost of your project.

Once the question of weight is out of the way, you’ll need to consider the dimensions of your loft. Is there enough headroom to make everyday use comfortable? Extra space may also be required for water tanks, heating systems, pipes, and wiring, depending on what plan you have for your loft post-conversion. Adding stairs to your loft will also require a fair bit of room, as these stairs will need to rise over any current staircase. If you’re working with a designer, you should always ask them to make it clear exactly how much headroom there will be in the finished product.

What Type of Loft Conversion Do You Want?

Once the initial questions of excess weight and headroom are out of the way, there are a few more factors to consider before converting your loft.

Internal Conversions

These conversions are built using only the existing space within your loft. Generally, this type of loft conversion requires the fewest alterations to your roof (such as adding roof windows or insulation) and can be considered the “budget” option.

Dormer Conversions

These conversions involve the construction of a dormer window to add a bit of extra space, typically used when converting a loft into a bedroom or study. As expected, this can bump up the cost of your project quite a bit, and you may need to obtain planning permission.

Mansard Conversions

A mansard conversion will require significant changes to your roof. One or both slopes of your roof will be replaced with near-vertical walls, which are then covered with a flat roofing material. These conversions are best suited to homes that lack loft space.

Modular or Prefabricated Loft

As the name suggests, modular lofts are prefabricated offsite, and will require the whole roof structure to be removed and changed so they can be installed. This is a very expensive solution but allows a greater degree of freedom than working with your existing loft space.

Do Loft Conversions Require Planning Permission?

Internal loft conversions (that do not alter the roof space) do not generally need planning permission but will still need to be approved under the Building Regulations. We’d recommend consulting a professional to ensure that your project has all necessary approvals before you begin. This will prevent any issues from cropping up later.

If you’re undertaking an external loft conversion, such as dormer, mansard, or prefabricated lofts, you’ll need planning permission from your local authority. Planning applications can be easily submitted online via the Planning Portal website. You can also find useful guides not only on creating your plan but also on building and completing it.

Modifying Your Roof Structure

Whether you’ve got a traditional “cut and pitched roof” or a more modern trussed rafter roof, the timbers supporting your roof structure will need to be removed to make way for furnishings. They will then need to be replaced by modern, less obstructive supports. This is often the most expensive part of a loft conversion, so it’s vital to do your research on this. To give you a rough estimate, for a 30m2 loft conversion, replacing the supporting timbers would cost around £4,400, not including scaffolding or internal preparation.

Next, you will need to fit floor joists above any existing ceiling joists, so your loft can handle the increase in foot traffic post-conversion. These can then be covered with plaster or chipboard to form the base of your new floor. This will of course remove some headroom, which will need to be accounted for when planning. In smaller lofts, these floor joists can even be used as supports for the sloping rafters. You can do this by building a dwarf timber stud wall (ashlering) between the two, removing the internal struts and braces afterwards.

Finally, it’s time to consider the position of any pipes or wiring that will need to be laid. At the very least, you will need to install a mains-connected fire alarm, which will require professional installation.

Installing Stairs in a Loft Conversion

Installing a new flight of stairs can be one of the trickiest parts of a loft conversion. As expected, there typically isn’t much space to work with when doing so. A tight, winding staircase can work in a pinch, but it’s very difficult to use when moving furniture. An ideal staircase would be a continuation of an existing set of stairs, but this isn’t always possible.

If you do decide to include a staircase in your loft conversion project, you should ensure that your plans fall within building regulations. The stairs must be put in a location that leads to a hall with an external door, to give anyone in the loft a safe escape route in the event of a fire. Learn more about where to put stairs in a loft conversion.

Adding Natural Light with Roof Windows

As with any comfortable living space, plenty of natural light is key to stop your converted loft from feeling drab and dreary. For basic internal loft conversions, we’d recommend installing roof windows, as these can be fitted with minimal structural alterations. We stock a fantastic range here at Roofing Megastore, including leading brands VELUX and FAKRO.

Dormer loft conversions will naturally feature a dormer window as standard, which will bathe your new loft space in natural light along with adding space. Mansard and prefabricated lofts should also be made with plenty of roof lights included, with different options suitable for each.

Fire Safety Considerations

Changing an unused space, or a room meant only for storage means that your loft will now be subject to a whole host of new fire safety regulations. These are vitally important to get right, so we’re going to go through each point below:

  • One escape-sized window per room – Whether you’re doing a loft conversion in a bungalow or a multi-storey property, you will need at least one window big enough for an occupant to escape through in the event of fire.
  • 30 minutes of fire-protection – You will need to ensure that the new floor in your loft can provide at least 30 minutes of fire resistance. This may require re-plastering the ceiling below it to achieve this.
  • Fire Door – Either the bottom or the top of your new staircase will need a fire door. This could mean replacing one or more doors currently in your property. This should be clearly indicated on your loft conversion plans for building control.
  • Smoke Alarms – As with the rest of the rooms in your house, a mains-powered smoke alarm will need to be installed into your loft conversion.

Insulating Your Loft

As utility bills continue to rise, and energy efficiency requirements become ever more stringent, installing proper insulation in your loft has never been more important. Not only will you be satisfying regulatory requirements and saving on energy bills, you’ll also be making your home a much more comfortable place to live in year-round.

Finishing Touches

Now that we’ve covered building the main structure of your loft conversion, it’s time for you to add those final personal touches. These will entirely depend on your tastes and what you’d like your new loft space to be, but it’s time to get out your paint brushes, order your furniture, and add some real personality to your newly converted loft.

How Much Will Your Loft Conversion Cost?

The cost of a loft conversion will vary massively depending on the size of your loft and the type of conversion you have chosen, but most start at the £15,000 mark with higher end conversion topping out around £55,000.

This takes into consideration:

  • Project Management
  • Scaffolding
  • Internal Preparation
  • Alterations
  • Steelwork to Support Structural Changes
  • Roof Coverings
  • Electrics
  • Joinery
  • Staircase
  • Plastering
  • Decoration

While this may be a jaw clenching number to some, loft conversions have been proven to be a sound investment, in some cases adding as much as 21 percent to the total value of the property. Taking that into account, in addition to the obvious personal benefits of having an extra room, with proper planning and execution you could have your own conversion sorted in as little as 6 – 8 weeks.

In Closing

There's no denying that a loft conversion is a big project, with a big list of things to consider. We hope this blog has helped demystify the process for you, so you can make better decisions when you come to do your own loft conversion.

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