Skip to content

Loft conversions: what are the building regulations?

Whilst a loft conversion may not require planning permission, your project will still need to comply with building regulations...

A loft conversion is a fantastic way to increase your living space. While you may be able to carry out the work without planning permission (permitted development may be enough), your loft conversion project will still need to comply with building regulations.

Building regulations are statutory requirements for all building projects, so you are legally obliged to ensure your loft conversion adheres to these rules.

When you work with CR Designs, our experienced architects and structural engineers can prepare plans and building control drawings that incorporate the regulations into the loft conversion process.

Staircase regulations:

Stairs are an integral part of any loft conversion and come with their own set of regulations. Your building control drawings will need to consider:

Width and height:

When designing your staircase, it’s important to remember that you need to be able to get furniture up to the loft space via the stairs. There are also fire safety considerations (more on this in a moment).

What’s more, there needs to be a landing at both the bottom and top of the stairs and the width and length of these should at least be the width of the stairs.

Whilst there is no minimum width for the staircase itself, it’s generally accepted that you should keep to at least 750mm. However, in the case of loft conversions this can be pushed to 600mm.

Rise and going

The vertical part of the stair (known as the riser) should be a minimum of 150mm and maximum of 220mm in height.

The part of the stair you step on (known as the going) needs to be at least 220mm and no more than 300mm.

Positioning and pitch

The top of the stairs needs to be positioned at the highest part of the loft, with a pitch or angle nor more than 42°.

Head room:

There needs to be 2m of clear headroom above the stairs. This headroom must be constant throughout the whole staircase, however regulations allow this to reduce to 1.8m at the lowest point if the stairs are under a sloping roof.

Handrail, balustrades & spindles

Your building control drawings must include a handrail between 900mm and 1000mm high.

Balustrades at least 900mm light must be added to any staircase that is exposed and are higher that 600mm.

As a safety precaution, stair spindles must be installed with a maximum distance between them less than 100mm.

Non-traditional staircases

If space in your loft conversion is limited, you may be able to opt for an alternating tread or paddle staircase, a fixed ladder or a spiral/helical staircase.

Each of these types of staircases come with their own set of regulations, so your architect and structural engineer will consider these in your building control drawings.

Fire safety regulations

There are a number of rules concerning fire safety that must be addressed in your loft conversion building control drawings:

Fire doors:

Any existing loft doors will need to be replaced with fire doors. The ideal door should be able to resist heat for at least 20-30 minutes.

Staircase:

Like the fire doors, the staircase installed in your loft conversion must be fire-resistant for a minimum of 30 minutes. This also applies to any glazing you have within the stairwell.

Smoke alarms:

Building regulations require you to install a smoke alarm into all new spaces created by the loft conversion. You must also ensure that they are linked to the mainline.

Fire containment:

Should a fire occur, your loft conversion must have walls are fire-resistant enough to limit the damage caused.

Floor joist regulations

If you are converting a loft that hasn’t previously been used as living space, then the chances are the existing joists will need to be replaced.

There are rules to follow and your structural engineer will be able to calculate the size of joist that is required when preparing your building control drawings.

Insulation regulations

Installing the correct insulation will limit the amount of heat your loft conversion loses through the roof.

The type of insulation you need will depend on whether you already have insulation in your roof space and if so, how effective it is.

Other features of your loft conversion that must comply with building regulations

The above list is by no means exhaustive and there are many other regulations that you will need to follow to ensure that your loft conversion is approved by building control.

When preparing your building control drawings, you and your structural engineer will also need to consider:

  • Doors and windows
  • Drainage
  • Electrics
  • Walls and roofing

Our building control drawings and structural specification packages

If you wish to convert your loft into living space then our team of experienced architects and structural engineers can turn your ideas into reality.

We will prepare concept design and planning drawings, aswell as building control drawings and structural calculations within weeks. We will then submit your plans to the council and act as your agent for the duration of the project.

Our comprehensive and affordable design packages are suitable for all loft conversion projects, not to mention extensions, garage conversions and new builds.

Find out more about our building control drawings and structural specification packages.

Convert your loft with CR Designs

To discuss how we can help transform your home, get in touch today.

Start a project today

Posted on Google Google
MMA profile picture
MMA
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Very good experience! (Not giving 5, as you have to sometimes chase for an update)
Posted on Google Google
Matt Ginger profile picture
Matt Ginger
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
After doing our research and speaking with a few different companies, we decided to go with CR Design Services. The ask was to redesign the downstairs space in our Victorian Terrace house. They understood the brief so quickly and challenged us on design options, this was very welcome- saving us money in some areas but telling us to spend it in others. To make sure you get the best end result. We can’t recommend this company enough, the quality of the work and the attention to detail is fantastic. They are also impressive on responding to queries, either the day of or 1 day after - due to the nature of work, you will have a lot of queries. So having a business that actions them so quickly is great. A big thank you to Asal, Chris and the team. We will be using you in the future. Thanks
Posted on Google Google
johann crichton profile picture
johann crichton
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Chris was fantastic when I needed a structural plan drawn up for my loft. So helpful and so easy to deal with going out of his way to help and affordable prices . I couldn’t fault his service in anyway and highly recommended .
Posted on Google Google
ELAINE SNEDDON profile picture
ELAINE SNEDDON
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Excellent experience with CR design - I can 100% recommend their services and would definitely use them again. They helped me navigate the confusing world of planning permission with listed buildings to acheive a successful outcome.
Posted on Google Google
Stefka Arsovska profile picture
Stefka Arsovska
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Great company to deal with!!! Excellent , professional services done in accordance with contract in timely manner. Very polite staff, always keen to help. For hassle-free design services, support for the council's Planning Permission and Building Regulations applications I strongly recommend CR Design Services. I would definitely used them again.
Posted on Google Google
David Henness profile picture
David Henness
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Used CR Design to design a renovation for a bungalow. The firm was very professional. They listened to our ideas and were able to provide a great design as well as help with building regulations. A great service that I would certainly recommend.
Posted on Google Google
Cameron Stanwick profile picture
Cameron Stanwick
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
10/10 service - would not recommend any other architecture company to this degree. Approached them with 3 weeks notice after being with another architect firm that said the job couldn’t be done / wouldn’t be approved. CR Designs took on the job, drew the plans to what I needed and submitted them to my planning officer. Over the moon to say the plans were granted after a long 6 months of initially submitting my application - thank you so much!
Posted on Google Google
Darren Myners profile picture
Darren Myners
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
I had a project that was probably quite awkward for the team due to the numerous changes requested. Despite this, the team was very supportive and produced high-quality work.
Posted on Google Google
Elizabeth Every profile picture
Elizabeth Every
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
We needed a revised plan drawn at short notice during lockdown in the middle of a building project. Laura was able to respond quickly, quoted a fixed price, liaised with us to get the information accurate and completed our plans within three weeks. We have now received planning permission and are able to get on with minimum delay. Thank you for your reliable, fast and professional service. We have just received approval for a retrospective plan to complete the above project two years further on and have received the same professional and thoughtfull service from Caroline and her team. Highly recommended.
Posted on Google Google
Rosslyn Haith profile picture
Rosslyn Haith
Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google.
Most professional organisation and worked to tight timelines, everyone I dealt with were knowledgeable, delivered a high quality service and their work was to an excellent standard. They made excellent suggestions - the team led by Chris with Asal and Caroline were a pleasure to work with. They took my architects high level drawings and created comprehensive building plans to the eco passive house standards that we required. Exemplary!