Loft Conversion – What You Need to Know (Free Guide)

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In this article, we’ll look at everything you need to consider when thinking about a loft conversion in your home. Typical examples of converting a loft include adding an extra bedroom, a hobby room or a home office.

For many people, converting a loft for additional space is the next best option to building a house extension or relocating.

Let’s start with the first question you need to ask yourself if you want to know how to convert a loft.

Can you convert your loft into another room?

Not all loft spaces are suitable for conversion.

Some are too small and some properties aren’t structurally strong enough to hold the extra weight.

The minimum height for a loft conversion is 2.2 metres at the highest point. You’ll need to get your tape measure out to check the height between the floor and the uppermost point in your attic.

If you have 2.2 metres or more, you should be able to convert your loft into a usable space.

Source: Homebuilding & Renovating

Check the pitch of your roof

The term ‘roof pitch’ refers to the slope of your roof. You don’t need to know the exact pitch of your roof at this stage, just take a look at it and picture yourself moving around inside.

  • Will you be comfortable?
  • How many steps can you take from the centre point outwards before you need to duck?
  • Can you stand upright without bumping your head or leaning to one side?
  • How much furniture can the space accommodate?
  • What kind of storage will you use?

Some roofs require additional structural support

Homes built in the UK after the 1960s may require additional structural support. This is because builders started using roof trusses instead of old-style timber-framed roofs. To make the loft conversion work in a house with a roof truss, some parts of the truss need to be removed, hence the need for additional structural support.

What does the term ‘structural support’ mean in this situation? It usually means reinforcing the floor and making sure load-bearing walls and foundations can take the extra weight of the loft conversion.

Houses built pre-1960s typically used rafters. You can tell which kind of roof you have simply by looking at it through the loft hatch. If you see a timber-framed structure filling most of the space, it’s a roof truss.

Watch the video below by Robin de Jongh for a detailed explanation of how to deal with a roof truss when converting a loft or attic space. It’s not very long and clearly explains the process of removing the trusses and strengthening the remaining structure and rafters.

It’s definitely worth a few minutes of your time if you’re researching loft conversions and how they work.

For similar videos, check out Robin de Jongh’s YouTube channel, Structural Engineering How-To.

Have a look at similar properties in your area

If you’ve looked at your attic space and still aren’t sure if your loft can be converted, have a walk around your neighbourhood. Look out for houses similar to yours with loft conversions. Sometimes it’s not easy to tell, but any with a skylight window is a likely contender for a successful loft conversion.

What are the different types of loft conversion?

There are several different types of loft conversion worth considering. Here’s a brief description of each one.

  • Roof light loft conversion – this is the simplest form of loft conversion. The name comes from adding one or more windows to the roof to introduce natural light into the converted attic space. In most cases, you’ll want to add a staircase for ease of access, too.
  • Dormer loft conversion – there are a few different types of dormer loft conversion but typically they’re a box-shaped addition to the existing roof that creates extra headspace and floor space inside the loft area. Dormers work best on houses with small lofts.
  • Mansard loft conversion – is the one to go for if you have the budget and want to dramatically transform your home. A mansard loft conversion effectively adds another storey to your house. The roof slope will change from the current angle to an industry-standard 72 degrees and the conversion spans the entire width of your house.
  • Hip to gable loft conversion – this kind of loft conversion works for detached and semi-detached houses by making use of the space between the edge of the hipped roof* and the gable end of your house. The new loft is created by increasing the height of the gable wall and extending the hipped roof to meet the new wall.

*A hipped roof (also hip roof) is a type of roof that has no gable end. Instead, its sides slope down to the walls of the house.

Do you need planning permission to convert a loft?

Usually, you don’t need planning permission for a loft conversion unless you extend or alter the roof space and it exceeds specified limits and conditions.

Most homes come with something called ‘Permitted Development Rights’ which means you can convert your loft without planning permission. ‘Permitted development rights’ generally apply to houses but not flats or maisonettes.

In certain areas of the country, typically known as ‘designated areas’, permitted development rights are more restricted. Here are a few examples:

However, there are limitations so it’s best to check the rules for your property and your local area. The list of limitations listed below comes from the Planning Portal website (source).

Limitations on the proposed development:

  • Materials must be similar in appearance to the existing house
  • Volume of enlargement (including any previous enlargement) must not exceed the original roof space by more than:
    • 40 cubic metres for terraced houses; or
    • 50 cubic metres otherwise
  • Must not exceed the height of the existing roof.
  • On the principal elevation of the house (where it fronts a highway), must not extend beyond the existing roof slope.
  • Must not include:
    • verandas, balconies* or raised platforms; or
    • installation, alteration or replacement of any chimney, flue, or ‘soil and vent pipe’
  • Side-facing windows must be obscure-glazed; and, if opening, to be 1.7 metres above the floor of the room in which they are installed.
  • Construction must ensure that:
  1. The eaves of the original roof are maintained (or reinstated)
  2. Any enlargement is set back, so far as practicable, at least 20cm from the original eaves (see pages 35-36 of the Technical Guidance below for more details)
  3. The roof enlargement does not overhang the outer face of the wall of the original house

With the exceptions that:

  • Points 1 and 2 do not apply to the relevant parts of any hip-to-gable enlargement.
  • None of these three points apply to the relevant parts of any enlargement that joins the original roof to the roof of a side or rear extension

Building regulations

If you don’t need planning permission for your loft conversion, you WILL need to follow building regulations made under The Building Act 1984 if your property is in England or Wales.

Scotland and Northern Ireland each have their own set of regulations.

Before you start a loft conversion, contact your local council or authority for information about building regulations and how they affect your property.

You can find all the information you need to start planning a loft conversion by visiting government and local council websites.

Reference points and further information

Disclaimer: This guide was written after undertaking intensive research from around the web. You should always check with authorities and local councils before undertaking any kind of building work on your home.