Why choose a loft conversion?

A loft conversion can be one of the most straightforward and cost effective ways of creating extra living space within your home. It can save you the expense and upheaval of moving house and can be done without reducing your garden space (as an extension might) and, in some cases, without altering the outside of your house. The work can often be done without planning permission. A well thought out and professionally executed loft conversion can also add value to your house. And your new room might just benefit from some great views too!

Is my house suitable for a loft conversion?

Not all houses are suitable for loft conversions, although there are ways to make one work for most types of houses. Your best bet is to consult an expert early in your plans to understand the implications for your home, identify the workable dimensions of the space available and confirm the best approach. Various factors affect how suitable your home is for a loft conversion, and the most suitable type of conversion for you.

  • Head height: there’s not much point in having your loft converted to a new room if you can’t stand up in it! Measuring from the bottom of ridge timber to top of ceiling joist, the usable part of the roof should be greater than 2.2m. If it’s lower, there are solutions. You can raise the roof, although this can be expensive and may require planning permission. Alternatively, the ceilings of the rooms below could be lowered if they are particularly high (they still need to be 2.4m high), but this is another big job.
  • Pitch angle: the higher the pitch, the higher the usable space is likely to be. If dormers are used, the floor area can be increased further.
  • Type of structure: if your house was built before the 1960s, the roof is likely to have a traditional frame where the rafters, ceiling joists and supporting timbers were cut to size and assembled on site. This roof type is often most suitable for conversion as the space can be easily opened up by strengthening rafters and adding support. Post-1960s, some homes were built using factory-made truss sections which use braced diagonal timbers. This was great for the builder at the time, but is not so great for conversions. Usually there are no loadbearing structures beneath so opening up the space requires greater structural work. Steel beams may need to be run through the length of the house. Alternatively, the whole roof can be taken off and replaced with a more suitable structure. Do not consider this as a DIY project!
  • Obstacles: if there are water tanks or chimney stacks, for example, in the roof space, they may impact the build.

What types of loft conversions are there?

There are four common approaches to loft conversions, each with their own pros and cons.

  • Dormer: this type of conversion can be built on various styles of homes. It’s simply an extension to the existing roof to create additional floor and head space – your new room might become the largest in your home! The dormer protrudes from the roof slope and the room will have vertical walls and a horizontal ceiling. Some dormer conversions don’t require planning permission but you’ll need to check the rules in your local area. A builder may know if they’ve done similar work in the area before.
  • Hip to gable conversion: this type of conversion involves fairly major changes to the roof and tends to be used where there’s not enough existing internal room for conversion. The gable wall is built up to the ridge line and a new section of roof is built to fill the gap. In most cases, the new gable can be built in materials to match the existing wall.
  • Mansard loft conversion: this type of conversion requires the most work as it changes the structure of the roof, but you end up with loads of extra space. It will usually require planning permission. The extension has two slopes: a lower slope at 72 degrees or below (so it counts as a roof rather than a wall) and the top section which is almost horizontal. The gable walls are raised at either side of the house then a timber frame is fitted.
  • Velux loft conversion: also called a rooflight conversion, this is the most common type of conversion. It can be a cheaper option than a dormer conversion, but you tend to compromise on space and it’s not a suitable option if headroom is limited. Velux windows are installed to fit flush with the roof line. Since the rest of the roof structure is largely untouched a velux conversion doesn’t usually require planning permission (but do check with your local planning department or your builder).

What else do I need to think about?

  • Floor: the existing joists may not be adequate for the conversion’s floor and may not comply with building regulations so work might need to be done at this level.
  • Insulation: an essential part of the build, there are different methods of insulating your space, but there are building regs that you have to meet.
  • Staircase: the actual position that your staircase can be placed will depend on the layout of the floor below and the height above the staircase – there are regulations to comply with. One option is to put the staircase where the current airing cupboard is, but this will mean moving the hot water system. Another option is to sacrifice space from a current bedroom for the staircase, but consider this carefully as smaller bedrooms may affect the value of your home.
  • Windows and dormers: your new conversion will require natural light and ventilation. The most common type is rooflights. These follow the pitch line of the roof and are likely to be allowed without planning permission. Dormers can add space at the ends or sides and are particularly good where the pitch is tight. A mixture of types can normally achieve best light and fire escape compliance.
  • Fire Safety: safeguards need to be put in place. All habitable rooms in the upper storeys served by a single staircase should have an escape window (this means an openable area of at least 0.33m2 and not more than 1.1m about floor level). For loft conversions to a two storey house, more stringent provisions apply. Don’t forget a mains powered smoke alarm.
  • Plumbing, electrics, heating and water: these requirements will depend on what the space will be used for. If you’re incorporating a bathroom or multiple rooms, for instance, requirements will be more complex.

As you can see, there are a quite a lot of things to think about, and a lot of building regulations which need to be satisfied. That’s where working with a professional builder with experience in loft conversions can really pay off.

How long does a loft conversion take?

This depends on the complexity of the build. As a guide, from start to finish, a conversion should take around 8 weeks. Your builder will be able to give you an accurate estimate based on your individual plans, roof type and requirements.

How much does a loft conversion cost?

Budgeting is an important aspect of any building project. It’s important to understand cost implications early so you can be sure that a loft conversion is your best option.

Costs of a loft conversion can vary hugely from project to project, depending on the size of the property, the roof type and conditions, plumbing that needs relocating, any complications such as chimneys and, of course, your plans for the space. Getting a quote from a builder before you start any work is the only real way to get an accurate cost for your project.

Taking on some parts of the build as a DIY project may be tempting to keep the costs down but often the structural work required can be quite complex. An experienced builder will be able to make sure you don’t forget anything or make any costly mistakes. They can also contribute some great ideas on how to make the best use of the space you have. Seeking expert advice and help from a builder is a very sensible choice.