The construction part of a loft conversion usually takes between 6 to 12 weeks. The complete project, from the first design sketch to the final touches, typically spans 4 to 6 months once you account for planning, permissions, and legal checks.
Knowing these timelines is the first step to planning your project. It helps you prepare for the work ahead and gets you closer to enjoying that new bedroom, office, or quiet retreat. Let’s break down exactly what happens during those weeks and months so you know just what to expect.
For the person who wants the short story, here it is. The actual construction work for a loft conversion typically takes between 6 to 12 weeks.
But the total project, from your first phone call to the final coat of paint, is longer. Here’s a quick look at how different types of loft conversions stack up for the building phase:
Type of Loft Conversion | Average Construction Time | Best For |
4 – 6 Weeks | Speed and budget | |
6 – 8 Weeks | Adding lots of headroom | |
Hip-to-Gable | 8 – 10 Weeks | Semi-detached homes |
Mansard | 10 – 12 Weeks | Maximum space creation |
This table covers the building work. Now, let’s look at the full picture, because good projects start long before the first hammer swings.
The builders don’t just appear with their tools the day after you decide you want more space. A smooth loft conversion has three clear phases. Getting the first two right makes the third part, the actual building, go much smoother.
This is where your idea gets put on paper. It’s the foundation for the entire project.
First, you’ll work with an architect or a design-build company to figure out what’s possible. They will measure your loft and discuss what you want from the new space. Next, they create detailed architectural drawings. These are the blueprints for your builder.
You will also need a structural engineer. This person does the calculations to make sure the new floor and any changes to the roof are strong and safe. Their plans are a must-have for getting building approval.
This can be the longest waiting game of the whole project. You need to get all the legal boxes ticked before work can begin.
Many loft conversions fall under Permitted Development rights. This means you don’t need full planning permission, which is a big time-saver. Your designer can confirm if your project fits these rules.
If your plans are bigger or you live in a conservation area, you might need Planning Permission. Applying to your local council and waiting for their decision usually takes 8 to 12 weeks.
You’ll also need to think about your neighbors. A Party Wall Agreement is a legal document between you and your neighbors if you share a wall that will be worked on. You must give them two months’ notice. If they agree straight away, it’s simple. If they ask for a surveyor, it can add a few weeks to the schedule.
Here we go! This is when you see your new space come to life. A well-organized team will follow a clear schedule.
Your project is unique. A few things can make your timeline shorter or longer than the average.
As you saw in the table, the type of conversion makes a big difference. Putting in a couple of Velux windows is a much faster job than removing and rebuilding the entire side of your roof for a Hip-to-Gable conversion. More space and more changes mean more time.
What’s hiding in your attic? An older home can sometimes reveal surprises once work begins. For example, the existing roof timbers might need strengthening. A good builder will assess this early, but sometimes unexpected issues can add time.
Great builders are often popular. You may have to book them a few months in advance. Once they start, how they manage the project matters. An efficient team that coordinates its tradespeople well will finish much faster than a disorganized one.
Some things are out of anyone’s control. A week of heavy rain can stop all roofing work. Sometimes, there can be delays in getting specific materials like windows or special tiles delivered to the site.
You can’t control the weather, but you can take steps to keep your project moving.
Order key items ahead of time. Custom-made windows or specific bathroom fixtures can have long lead times. Order them as soon as your plans are finalized.
Yes, absolutely. Most of the work is contained within the loft and accessed via the scaffolding. Your home life should not be too disrupted until the final few weeks when the staircase is installed.
A simple Velux or rooflight conversion is the fastest. Since it doesn’t change the shape of your roof, the construction is very straightforward and can be done in as little as 4-6 weeks
If you need planning permission, you should add 8-12 weeks to your pre-construction schedule. This is the standard time a local council takes to review your application and give a decision.
It can. You must legally give your neighbors two months’ notice. If they give consent right away, there is no delay. If they dissent or want to appoint their own surveyor, negotiating the final agreement can add weeks or sometimes months to your timeline before building can start.
Feeling clearer about the timeline? A loft conversion is a big project, but it’s a manageable one. While a typical build takes 6 to 12 weeks, the whole journey from idea to finished room is closer to 4-6 months.
Knowing these steps helps you plan your life and your budget.
If you’re ready to see what’s possible with your own loft space, the next step is a simple chat.
Contact our friendly team today for a free quote and a personalized timeline for your project!
We’re a trusted loft conversion company in Nottingham, helping families create more space and add value to their homes with tailored designs and expert craftsmanship.
Signup our newsletter to get update information, news, insight or promotions.
© 2025 Copyright All rights reserved by Loft Conversion Nottingham.
Your Loft Solutions
