Loft conversion advice

[Chris171280]

Planning on a loft conversion, it might take me a year or 5 to complete but I want to do the work myself, I enjoy building/making stuff and obviously it'll be cheaper than getting a
builder in to do it.

I want to do it properly with building regulations all correct and signed off etc. Seems a bit of a minefield.

Can anyone recommend any sources that go into all of the current regs and requirements etc?

A mate told me just to contact my local building control at the council and ask for advice but will they actually be helpful or just treat me as another idiot who wants to bodge a loft conversion?

I've done a plan of what I want would appreciate any input on the basic concept.

Pics show the current condition and what I plan. Stairs in the plan are not quite right, pic included of actual stairs I was thinking of using.

The house is a semi, so I'll need to sort out the party wall agreement with the neighbour. Plan is to attach a joist to the wall then span joists from that across to the wall that is supporting the purlins shown, 3.7m. Then do the same for
the other side which is 3.1m. Was looking to use C24 63x170 joists.

Input welcome

 

[Wayners]

You need an architect. They will know a structural engineer. Get prices. I paid architect a bit more and that would cover planning cost and any alterations all for one fee. I paid structural engineer separately.
Problem I had was the fixed height of roof as I live in a semi detached.
I don't know where you will find current regs

 

[foxhole]

Found local council very helpful and my Architect was well acquainted with them so knew what was acceptable before he drew up the plans.

 

[freddiemercurystwin]

As a DIYer unless you are prepared to spend ages trawling through the various legislation, typical ways of achieving your proposals and siphoning out the inaccurate from the accurate I would look for a decent architectural technician or other similarly qualified person who can produce a decent set of drawings/Building Regs application, if you find a good one and they understand and appreciate where you're coming from they can hone the design to be DIY friendly and provide more input into the construction methods and material choices. Have a look at my post in this thread for a typical process with regards to getting someone onboard but obviously that thread is slightly outdated now. Their fee is quite likely to be the most valuable bit of money you spend on the whole job. BC can be very helpful but don't bank on it, they're not an advisory service and some you'll definitely put their back up asking them stuff all the time. https://www.diynot.com/diy/threads/questions-about-a-loft-conversion.418758/#post-3250539

 

[noseall]

Planning on a loft conversion, it might take me a year or 5 to complete but I want to do the work myself, I enjoy building/making stuff and obviously it'll be cheaper than getting a
builder in to do it.

I want to do it properly with building regulations all correct and signed off etc. Seems a bit of a minefield.

Can anyone recommend any sources that go into all of the current regs and requirements etc?

A mate told me just to contact my local building control at the council and ask for advice but will they actually be helpful or just treat me as another idiot who wants to bodge a loft conversion?

I've done a plan of what I want would appreciate any input on the basic concept.

Pics show the current condition and what I plan. Stairs in the plan are not quite right, pic included of actual stairs I was thinking of using.

The house is a semi, so I'll need to sort out the party wall agreement with the neighbour. Plan is to attach a joist to the wall then span joists from that across to the wall that is supporting the purlins shown, 3.7m. Then do the same for
the other side which is 3.1m. Was looking to use C24 63x170 joists.

Input welcome

A DIY lofty?

Of all the the things I'd rather not do as a DIYer, a lofty is up there near the top.

 

[Chris171280]

Cheers guys.

I have found a local architect that does a free consultation and feasibility check, will get in touch with him and take it from there.

A DIY lofty?

Of all the the things I'd rather not do as a DIYer, a lofty is up there near the top.

How hard can it be?

I've fitted bathrooms, kitchens, windows, built a raised decking area, designed and built a shed.

Only DIY job I have done but REALLY didn't enjoy was pointing the back of my house, if I can see out my days without having to do anymore pointing I'll be happy

 

[noseall]

How hard can it be?

Up there with the best of 'em, in the domestic building difficulty leagues. And if you get into a pickle whilst the roof is open, Lord help you.
It's also a very Building Regulations rich environment, so building nous and experience is important. You also need to bear in mind that the new Building Control directives means that giving design advice no longer happens, now that the officers are under greater scrutiny and accountability.

On the plus side - at least you have a cut roof.

 

[Chris171280]

Up there with the best of 'em, in the domestic building difficulty leagues. And if you get into a pickle whilst the roof is open, Lord help you.
It's also a very Building Regulations rich environment, so building nous and experience is important. You also need to bear in mind that the new Building Control directives means that giving design advice no longer happens, now that the officers are under greater scrutiny and accountability.

On the plus side - at least you have a cut roof.

I'm confident I can do the actual 'work' but yeah the regs seem to be a bit of a minefield!

I'll admit I would be a lot more hesitant to attempt it if I had roof trusses!

 

[foxhole]

Cheers guys.

I have found a local architect that does a free consultation and feasibility check, will get in touch with him and take it from there.



How hard can it be?

I've fitted bathrooms, kitchens, windows, built a raised decking area, designed and built a shed.

Only DIY job I have done but REALLY didn't enjoy was pointing the back of my house, if I can see out my days without having to do anymore pointing I'll be happy

Consider how you will keep the home water tight with no roof when you are working alone and materials fail to turn up on time .

 

[Chris171280]

Consider how you will keep the home water tight with no roof when you are working alone and materials fail to turn up on time .

I'll start by making sure I've got everything I need on site when I need it, before I start each aspect of the work.

 

[^woody^]

The roof does not have to come off.

The issue is the knowing not the doing, and the knowing will include how to get over things that are not quite as they should be.

- Planning the location of the stairs is crucial - including alterations to the existing first floor, required landing areas, and headroom up the flight.

- Then how is the new floor going to be spanned - existing supports or new beams?

- Purlin removal? New or existing rafter supports? Bracing of altered timber. Ridge beam?

- Insulation requirements - thermal and acoustic ..... roof, floor and eaves.

- Fire safety and means of escape - floor, dormer, boundaries, escape route down the house.

You may struggle on a building notice as the inspector is there to inspect not help design. and there will only be about three visits.

If you get it designed, then you will only have to put it together. Any new structural beams or supports may well need structural engineer designing anyway.

And remember, the new floor is going higher, and the new ceiling is coming down lower, and it can be quite a bit.

 

[noseall]

The roof does not have to come off.

He'll do well to slip in some breathable membrane, under those battens.

 

[Chris171280]

The roof does not have to come off.

I think I'll be able to get the majority of it up through what will be the new staircase, before I fit the stairs.

The issue is the knowing not the doing, and the knowing will include how to get over things that are not quite as they should be.

I do have some much more experienced relatives/friends I can call on if(when) I get stuck.

- Planning the location of the stairs is crucial - including alterations to the existing first floor, required landing areas, and headroom up the flight.

If you can see the plans in my first post, I think the only place I can fit the stairs is between the 1st and 2nd bedrooms, I could put them in the cupboard in the 3rd bedroom and they would be above the current stairs, but then I'd have a 3 bedroom instead of a 4, when finished.

- Then how is the new floor going to be spanned - existing supports or new beams?

My initial thoughts are either joists fixed to the gable end walls with resin anchor bolts and then joist hangers or a steel beam at either gable with the centres of the joists on the centre supporting wall (will need to reinforce this as I'd be removing the centre section for the stairs, thinking beam above what used to be the old door frames)

- Purlin removal? New or existing rafter supports? Bracing of altered timber. Ridge beam?

Planning on leaving the purlins to form the top of the walls with built in storage underneath, still supported off the wall they're on now. I'm not planning a dormer so tbh was under the impression the roof structure would be OK as is? Obv with additional depth for insulation.

- Insulation requirements - thermal and acoustic ..... roof, floor and eaves.

Need to look into insulation and ventilation requirements more.

- Fire safety and means of escape - floor, dormer, boundaries, escape route down the house.

Fire doors, linked smoke alarms, possibly reboarding ceilings/walls to increase protection time.

You may struggle on a building notice as the inspector is there to inspect not help design. and there will only be about three visits.

If you get it designed, then you will only have to put it together. Any new structural beams or supports may well need structural engineer designing anyway.

And remember, the new floor is going higher, and the new ceiling is coming down lower, and it can be quite a bit.

I am definitely now fully onboard with getting professional help with the design/regs/calcs etc, I am aware I have a lot to learn and take into consideration.

I have 2.5m from the top of the ceiling joists to the underside of the rafters at the apex of the roof, with C24 75×175 joists(my guess from looking at span tables etc) I'm expecting to lose about 300mm including the additional roof insulation.

 

[Chris171280]

He'll do well to slip in some breathable membrane, under those battens.

Obviously I'm still learning but from what I understand so far, as long as I leave a 50mm gap between the roof felt and the insulation between the rafters then ventilation should be OK, is this not the case?

 

[RandomGrinch]

Obviously I'm still learning but from what I understand so far, as long as I leave a 50mm gap between the roof felt and the insulation between the rafters then ventilation should be OK, is this not the case?

Have you got eaves, or over fascia vents and ridge vents, to allow the free passage of air through this 50mm gap?

Although it's getting on a bit, and from a Welsh LA; I've found the attached document gives a good indication of some of the issues you'll be up against.

A matter that comes up regularly in the Electrics forum, is how are the electrics going to be signed off?
As an electrician is responsible for both the design and installation of circuits, they are often unwilling to simply test and sign off work that others have carried out.
BC can send out their own contractors to test and certify a DIY'ers work, but this cost will be passed on to you and can be more expensive than paying an electrician to do the work in the first place!
Even if you believe you are competent to do the work, it is often far less hassle to just get an electrician in.