How Long Does It Take To Convert A Loft

How Long Does a Loft Conversion Take?

Last Updated on December 5, 2020As loft conversion specialists, one of the most frequent questions we get asked is: “how long does a loft conversion take?’ Although no two loft conversions are the same, the same general timescale can be used depending on what type of conversion you might want. Understanding that every project is unique is significant.

There are various steps that you have to go through to get your new loft, and each step usually has a general timeline which we will explain below.

There are three stages of work which most loft conversion timelines generally have These are the design, planning, and build phases, and here we will discuss what happens during these stages:

design stageDesign Stage

The design stage, which mainly involves drawing up blueprint designs to plan your ideal loft room, is mainly a two-step process. The first phase will include scheduling a design team, which usually also consists of an architect, to visit and survey your home and environment in order to get vital information about the overall property. This will often take 2- 4 weeks.

The design team considers factors such as fire access, accommodation needs, the headroom, and access in order to design the ideal loft for your home. They will then get to work on drawing the plans of the proposed conversions.

Different designs will be drafted before you find the ideal design for your home and once you find and are happy with a model, the plans are then submitted to the planning and building control office to get any permissions if necessary for the loft conversions to move forward.

Getting planning permissions to start loft conversions

Although some loft conversions can be constructed without planning permissions, you will be required to satisfy building regulation laws.

Considering that it takes some time (4-6 weeks) to get your planning permissions approved, it’s important to know if you will need planning permissions before you start. You do this by making sure that your conversion meets the building regulations. Not following building regulations will make the process of designing and planning extremely tedious.

You can read more about the planning permisson by visiting the Planning Portal.


The actual time required for planning to be approved or for building control to visit can vary across the UK as the planning relates to the local authority timescales. The local planning office can only give you a rough estimate and a rough guideline to when the planning will be approved.

Ensuring that the planning is done right, that is, the design complies with the local rules and regulations will reduce the chances of your planning request being rejected and having to start the designing stage all over again.


As soon as the planning has been approved your Project Manager will now work with you in real time to agree upon a favourable start and finish date so that you are well informed on how the loft conversion will take shape. Building As soon as the planning approvals are approved, and the building control office is satisfied, a full schedule of the loft conversion works is then detailed in full. You will be able to know what exactly needs to happen, in what order, and the plan will then be executed.

For example, the team might start with the exterior and roof work – more about new roof cost, then the internal roof work, followed by the staircase installation to grant access to the loft, before joining the new room with the rest of the house, then adding built-in decorations, additional decorations and other furnishings.

The type of loft conversion will have different time frames to complete the sequence of works, and they vary considerably from each other.

Velux loft conversions are usually completed in less than four weeks since they are one of the simplest conversion types.

Depending on the overall size and roof work requirements, a dormer loft conversion may take four to six weeks to complete.

Hip to gable end conversions may also take up to 6 weeks to complete.

If the loft conversion requires a whole roof replacement as in a Mansard loft conversion, then the timescale to complete it could be around 7 or 8 weeks.

It’s also worth noting that there will be a wait time for the planning and creating of the room off-site even though some conversion methods such as extending a ready made room into the roof space reduces the overall work phase. Time will still be required for installing the staircase and creating room access.

Loft Conversion General Timeline

Loft Conversion General Timeline

If you have family and work to consider, it’s useful to know what to expect throughout the process of loft conversions. This is an average timeline of standard conversions:

Week 1 and 2

On the first week of the construction work, materials and equipment are prepared and organised for the work to commence. The deliveries are likely to arrive onsite, scaffolding will be raised, and a hole may be created in the roof for access. All of the work at this stage happens on the outside or within the roof space. By the second-week, construction should have already begun on securing the roof structure which generally depends on the conversion type.

Week 3 and 4

In the third and fourth weeks, the work is now inside as the loft floor, and floor supports are installed. Ventilation, internal stud walls, and insulation are also fixed. For more straightforward conversions, the external roof works are completed, and the windows are installed. Small conversions are usually completed by the fourth week.

Week 5, 6 and 7:

Complete staircase instalment and loft connection to the rest of the house takes place during the final phase. The staircase is additionally fixed with handrails and bannisters together with any plasterwork. The loft room is then plasterboarded, plastered and painted. This final stage sees the completion of carpentry works such as doors, cupboards, and skirtings. Plumbings and electric components are installed and tested. The room is then decorated to finish off the room.

If the loft requires multiple rooms or a roof terrace or a balcony, then it will take more time to complete the loft. Overall, loft conversions take a minimum of one month to approximately a maximum of three months.