On a standard house, a loft conversion is relatively straight forward – we have a framework and process for the build and it should last around 6-8 weeks. Most people don’t find the process disruptive and most steps are expected and accounted for.
When your house has a more unusual roof structure or shape, it can be more challenging. If you have a shallow pitched roof, for example, a loft conversion would be difficult. Shallow roofs are particularly difficult because there isn’t enough headroom so even adding large dormers won’t actually add much room to the internal space. Headroom shrinks by around 300mm when we add a new floor structure and insulation, so a small roof space will only get smaller as the loft conversion progresses.
An unusual roof doesn’t mean that you can’t convert your loft at all – simply that it will be more complex (and generally more costly) to do it.
Removing Your Roof
When you have a particularly difficult roof to deal with, the most logical way to progress is to remove your roof and create a new structure that accommodates your new needs. You would definitely need planning consent for this, and if you live in a terraced or semi-detached home it’s likely this will be refused.
If you do progress along this path, it can take around a month to complete – over this time, the roof will be removed and a temporary weather-proof canopy will replace it until the new roof is built. This process is sped up a lot if you go for a pre-fabricated roof (yes, they do exist!) – some companies make modular replacement systems that can be installed in two days since the majority of the work is done in a factory. The whole job can be turned around in a fortnight, but this is only really a viable option for larger loft conversions due to the cost.
Lowering Your Ceilings
If height is an issue but you have high ceilings in the rest of your house (which is often the case with townhouses), you may want to lower the ceilings on other storey to gain more height in the loft. This is far less drastic solution than removing the roof and replacing it, but it can be a lot more disruptive while the work is going on.
New joists are fitted beneath your existing ceiling on the floor below the loft. Once the new floor is fitted in the loft, the old ceiling is cut away to add up to 200mm of space in the loft conversion. This does add more to the cost of the project, but nowhere near as much as removing the roof.
Adding Telescopic Joists
Most loft conversions use steel beams to support the new floor structure and roof. The issue is that manoeuvring the beams into place at that height can be difficult, so sometimes we opt to use shorter 2m lengths that are bolted together on-site. This is a great solution for areas where access is restricted and there isn’t enough room to fit the full-length beams.
If there isn’t even enough room for those, we can use extendable, lightweight aluminium beams that slide in place alongside the existing floor joists. It reduces costs because you don’t need to hire a crane and you don’t need to remove as much of the original structure to fit them. We can even install them from the inside to save money on scaffolding.
Telescopic joists can also help with fitting a staircase since you wouldn’t have the issue of steel beams interfering with the headspace or access for the stairs.