2.2m Loft + Dormer - Is it Possible?

[Jag2010]

Hi everyone,

We are interested in purchasing a property and we are currently receiving a lot of conflicting information regarding the potential of a loft conversion.

The space between the lowest part of the ridge beam and the top of the floor joists is 220cm dead on. This doesn't take into account the height of the ridge beam itself... After googling, it seems that all loft companies are declaring it feasible to conduct a loft conversion in this space. However, I know that head room will be tight.

I did take an experienced builder with me into the loft and he is confident that a loft conversion with dormer is possible too. But there still remains an element of uncertainty because I don't really want to buy something and for it to be suddenly not feasible. I don't want to drop the ceilings in the floor below because thats just a whole new messy job.

I'm trying to wrap my head around how much space each element of the build is going to eat up so I have some questions:

1. Rather than attaching the steel beam to the bottom of the existing ridge beam, can we replace the timber ridge beam with a steel beam instead OR place the steel beam in line with the ridge beam? This will save us coming down lower down the original ridge beam.

2. Instead of putting steel beams above the joists to support the new struts or floor. Can these also be put in line with existing joists at the same level to save space?

3. Do you know any other alternative methods without going against planning permission?

4. I don't know much about the layers of materials that will be needed and where it all sits. Has anyone got a diagram of where everything effectively goes and how it eats up space to give the final head height.

5. Has anyone done a loft conversion with the above scenario of 2.2m from bottom of ridge to top of joists; if so how did the end ceiling height turn out?

Thank you in advance.

 

[freddiemercurystwin]

That is blinking tight for a loft conversion, looking back through some previous projects I did do the drawings for a loft conversion where the height from top of existing joists to underside of ridge beam was about 2.2m, ended up with about 2.04m maximum height at the ridge where the dormer was but that was a few years ago and the regs have changed a bit since so thicker insulation is needed.

What size are the existing rafters - as that will determine how much insulation underneath the rafters is required? You can get floor steel beams to sit within the floor joists depth, then then new joists can run parallel to the existing joists provided the existing floor joist direction permits that? You can sit the new structural ridge beam as high as the pitch of the roof permits but of course more disruption and messing about for the builder but not uncommon when space is tight. Will the loft be for say a 6ft person or kids? Whilst there's no minimum ceiling height in the Building Regs you do need to achieve around 2m above the stairs.