What is the timeline for a loft conversion?


What is the timeline for a loft conversion


Many of our clients ask us about the timeline for a loft conversion. Following our last blog on what to think about when you convert a loft to a bedroom, we thought it would be a good time to cover the timeline of such a conversion. 

There is, of course, no one or simple answer to how long your loft conversion will take.  It will depend on many factors, but the process follows a series of stages.


Stages of a typical loft conversion

  • The roof space is inspected for suitability.
    The main features being looked at will be height, pitch, access and obstacles such as a water tank or chimney stacks. This can be done fairly quickly and often at first inspection.
  • Suitability will be confirmed, plans drawn up, and budget costs advised.
    A Structural Engineer will also confirm whether the building can take the extra load of a conversion and suggest measures to take if it needs to be altered. Design options are then discussed before drawing up plans and arranging for a quote for the actual conversion cost. Again, timescale for this will depend on how busy your designer and surveyor are, but it’s typically a couple of weeks.
  • If planning consent is required, an application is made by your architectural designer.
    In Scotland, you don’t need planning permission for any internal alterations unless they involve the addition of a dormer or the property is a listed building on in a conservation area.


Dormer windows

For a dormer, you’ll need permission if: your home is a flat or within a tenement or four-in-a-block building; your home is in a conservation area; the dormer will be on a roof slope forming part of the principal elevation or side elevation where that elevation faces onto a road; the dormer will be on a roof slope and within 10 metres of the boundary of the curtilage of the house which that roof slope faces onto; the dormer will be higher than the existing height of the house, excluding the chimney; the dormer will take up more than half the width of the roof; the dormer will be within 0.3 metres of any edge of the roof slope of the house or it will include a balcony, a wind turbine, a raised platform or terrace.

Roof windows

Simple roof windows don’t require planning permission if the window doesn’t project more than one metre from the roof, unless you live in a listed building or conservation area. This typically takes 8 weeks. This is the statutory period for local planning departments to determine a planning application.  Time and hassle can be saved by getting your architectural designer to liaise with your council on your behalf.

  1. Cost is agreed through a competitive tender process and likely schedule proposed.
    This typically takes around 4 weeks.
  2. Once the statutory approvals are in place, the loft is cleared and prepared.
    This will include removing the water tank and other necessary items. This typically takes a few days.
  3. Rewiring is assessed.
    Wiring and other services attached to joists and binders will have to be removed and rerouted as part of the conversion. This assessment can be done in a short visit.
  4. New floor joists are fitted, insulated and floorboards laid.
    The spaces between the joists are filled with insulation to a depth of 100mm (10cm). Depending on the age and conservation status of your home, you may need sign-off from your local authority’s Building Control department before laying the floorboards. This typically takes a few days.
  5. Rafters are reinforced.
    This is done in accordance with the structural requirements so the purlins, struts and collars can be safely removed to open up the area. This typically takes 10 days.
  6. Dormers installed
    Dormers installed, if you’ve chosen them. This typically takes 10 days per dormer, assuming easy access.
  7. Rooflights installed.
    This takes around 4-6 hours per window.
  8. Staircase fitted.
    This typically takes 2-3 days.
  9. Dormers (if any) are tiled and vents fitted.
    Ridge and soffit vents will also be fitted at this point. his typically take 5 days per dormer.
  10. Dormer windows fitted.
    This typically takes 2-3 hours per window.
  11. Roof insulated.
    Insulation is placed between the rafters, with a 50mm air gap between the roofing felt and the insulation - for ventilation. This typically takes between 5 and 10 days, depending on how big your loft is.
  12. Partition walls, if any, are installed.
    This typically takes between 3 and 5 days, depending on how many are to be installed.
  13. Wall plates, first fix electrics and any plumbing installed.
    Wall plates provide a secure fitting for things such as radiators and the boxes for electric sockets and switches. This usually takes between 3 and 5 days, depending on how big your loft is, how many radiators you need, how many sockets you want and the plumbing required to service a toilet and/or shower or bath.
  14. Electrics upgraded.
    It may be necessary to fit a new consumer unit, or extra one, if the existing one has no extra capacity. Again this will depend on how much us required. Typically this takes between 3 and 5 days.
  15. Access panels for water, electrics and eaves storage fitted and water and power connected.
    Access panels are a useful addition. This typically takes 2 days.
  16. Walls plaster boarded and skirting and door architrave installed.
    The plasterboard attached to the studs and rafters will provide the basis for the decorative plaster skim. Typically this takes between 3 and 5 days.
  17. Bathrooms (if any) clad and air extraction system fitted.
    Typically this takes between 2 and 5 days, depending on the specification.
  18. Second fix, heating and finishes installed.
    Once any bathroom wall and floor tiling is done, the shower room items can be positioned and fitted. Second fix electrics and plumbing is done when possible. Radiators are fitted and connected. This typically this takes between 5 and 10 days, depending on the specification.
  19. Decoration is done.
    Obviously, this will depend on size of the new bedroom and the scheme chosen, but for a standard-sized room it will take between 5 and 10 days.


Many of these operations will be carried out with two or more contractors on site at any one time and therefore there will most likely be time overlap.


Typical total times

The average length of time for the most common loft conversions is:

      • Velux/rooflight: 6 – 8 weeks.
      • Dormer: 10-12 weeks.


Identifying issues early helps

Identifying planning issues early can help to streamline the project. All Design has an excellent record in securing planning approvals, and we offer realistic advice based on our experience with Aberdeen City Council, Aberdeenshire Council and Moray and AngusCouncils. Having good relationships with them helps to identify and address any planning issues at an early stage and effectively and efficiently deal with them.

Contact us to arrange a chat about your options and preferences, to get a realistic estimate for time and cost based on our experience of working on similar homes in your council area.


Get in touch

All Design is a dedicated, friendly team of architectural designers who work alongside external associates and consultants to help people across Scotland find property solutions through carefully-considered designs which respond to their needs, the site, budget and planning policy. 

We have more than 30 years of experience in the industry and thrive on using a creative yet practical approach to design to improve space for people.

Contact us for a FREE quotation.

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