Building regulations to be aware of for doing plans for a loft conversion and rear extension

[lora272]

I am doing some drawings/plans for my parents, who are having a loft conversion and a rear single storey extension done.

I would be really grateful if you could give some examples of what are some building regulations I should be aware of which would be relevant to drawing up the plans? I'm not really worried about the items which are a given when using standard construction methods like insulation level, its more like what items I should be conscious of when I am designing and when I am drawing up the plans themselves. It will be a Building Notice application and the builder should be able to pick up on the construction related regulations.

I have some experience working as a architects assistant with the drawings side but limited with the building regulations side for such residential projects.

From my research I am aware of the following:

Loft conversion:
- The requirements on staircases dims etc.
- Interconnected fire alarms in all rooms and landings, new and existing.
- Fire rated doors on all doors going onto the landing/staircase.
- A fire protected escape route to the outside.

Single storey extension:
- Windows area being 25% of extension floor area.

Can you think of any other?

Thank you for any help you can give!

 

[RandomGrinch]

I believe the 1/2 hour fire rating will also apply to the ceilings of the rooms below the loft conversion. They may need overboarding and insulating.

Ventilation of the space and the now concealed roof voids and rafters is also an important consideration.

You'll need to look at joist span tables and select the appropriate grade of timber.

Service feeds should be thought about - where is the heating supplied from? Is there plumbing for an ensuite? Is there a convenient route for an electric supply?
Are there spare ways on the existing consumer unit?

Here is an interesting guide to loft conversion by Swansea local authority. It may not be relevant to your area, but will give some food for thought!
https://www.swansea.gov.uk/media/12...Loft_conversions_and_building_regulations.pdf

It might be useful for you to investigate planning applications in your locality. Many are available online and should give you an idea of the detail needed to be provide to the local authority.

I suspect there may be some naievity in your assumption that the builders will pick up on construction related regulations. Builders will quote prices based on the plans provided. If your plans have missed out something crucial, resolving the issue later could come at a considerable extra cost.

 

[^woody^]

Foundations, structural supports, transfer of loads, structural integrity of the roof and triangulation of the rafters might come in to it.

Do things fit in between the new floor and ceiling levels?

Internal and external fire spread.

Party walls, chimneys, drainage, ventilation.

You must really know and trust any builder you let loose on a loft with a building notice. And have deep pockets.

 

[tony1851]

Roof Construction and Loft Conversion C.N.Mindham; Blackwell.

Loft Conversions J. Coutts; Blackwell.

Loft Conversion Manual; Haynes (makes a difference from car manuals).

The basis of the loft is the floor structure, which you need to get right first.
You might find some details on council's planning sites but probably not many as most loft conversions don't need planning permission.

"the builder should be able to pick up on the construction related regulations"
Don't put too much faith in that..........

 

[^woody^]

"the builder should be able to pick up on the construction related regulations"

I don't know about Architect's assistant, but that's proper Architect talk that is.

 

[lora272]

Thanks for your reply, its been very helpful and I will look at the link.

I suspect there may be some naievity in your assumption that the builders will pick up on construction related regulations. Builders will quote prices based on the plans provided. If your plans have missed out something crucial, resolving the issue later could come at a considerable extra cost.

You're right, I need to look into this is much more detail and be able to give more information on the plans.

 

[lora272]

Roof Construction and Loft Conversion C.N.Mindham; Blackwell.

Loft Conversions J. Coutts; Blackwell.

Loft Conversion Manual; Haynes (makes a difference from car manuals).

The basis of the loft is the floor structure, which you need to get right first.
You might find some details on council's planning sites but probably not many as most loft conversions don't need planning permission.

"the builder should be able to pick up on the construction related regulations"
Don't put too much faith in that..........

I will take a look at these books.

I have a lot to learn, but its pretty interesting

 

[lora272]

"the builder should be able to pick up on the construction related regulations"

I don't know about Architect's assistant, but that's proper Architect talk that is.

They are a bad influence, I know

 

[RandomGrinch]

Thanks for your reply, its been very helpful and I will look at the link

The link is a really good place to start from and should get you thinking about some of the issues involved.

This has the potential to be a really interesting and rewarding learning experience for you.
If you can find some help along the way (perhaps from the architect you assisted?), Then at least all the pressure won't be on your shoulders.

...and there are always some very wise people on here who have been there, done that and are willing to share their knowledge.

Good luck

 

[cdbe]

If you're producing full plans, why not do a full plans submission - you will get it checked to some extent by Building Control.