Simple extension, should I DIY the application and plans?

[Jilly]

I've got permission for an approx 9m2 extension with a flat roof and would like to increase it to 18m2. I have put the piled foundations in, in optimistic preparation on a Building Notice (first builder tried to persuade me to build it without pp). 

 

I've had a preliminary site visit from a planning consultant (we are in a Conservation Area), who recommended we opt for a green roof (the area is by the roadside, screened by trees) to increase our chances of approval. My own research had already reached that conclusion.

 

However, the Architect quite rightly pointed out that it would be a dark room with a low ceiling, so a sloping tiled roof with roof lights would be a better option, which I liked the sound of. 

 

All the fees quoted are likely to add up to over £8k and I'm seriously considering doing it myself, as I've only got £10k left in my self build pot atm, so this will be a slow build-as-you-earn thing. Is that bonkers? I'm quite arty and have paid for all manner of drawings previously, which I could pinch from, even though I don't use CAD. We have to use matching  black featherboard, so it's not stylistically very creative.

 

I know it's a risk (please give me the downsides), but I'm thinking it's worth it. 

[George]

Plans and drawings for planning permissions are straight forward enough. You can look at what others have submitted in the local area to get an idea of what they should look like and contain. 

 

Structural plans and building control details require more background knowledge. 

[Carrerahill]

50 minutes ago, Jilly said:

I've got permission for an approx 9m2 extension with a flat roof and would like to increase it to 18m2. I have put the piled foundations in, in optimistic preparation on a Building Notice (first builder tried to persuade me to build it without pp). 

 

I've had a preliminary site visit from a planning consultant (we are in a Conservation Area), who recommended we opt for a green roof (the area is by the roadside, screened by trees) to increase our chances of approval. My own research had already reached that conclusion.

 

However, the Architect quite rightly pointed out that it would be a dark room with a low ceiling, so a sloping tiled roof with roof lights would be a better option, which I liked the sound of. 

 

All the fees quoted are likely to add up to over £8k and I'm seriously considering doing it myself, as I've only got £10k left in my self build pot atm, so this will be a slow build-as-you-earn thing. Is that bonkers? I'm quite arty and have paid for all manner of drawings previously, which I could pinch from, even though I don't use CAD. We have to use matching  black featherboard, so it's not stylistically very creative.

 

I know it's a risk (please give me the downsides), but I'm thinking it's worth it. 

Father in law is a retired civil engineer, just started his own extension, I was doing the CAD work for him but he realised I was too busy and went to the art shop and got a set of pens and pencils and dusted off his drawing board. A total work of art, beautiful plans. 

 

Just another option!

 

Downsides, all I can say is it depends on your knowledge and skills pertaining to designing a building. 8K seems very very steep for an 18m² extension though... what are you getting for that? 

 

 

[Jenki]

@Jilly I drew my own house and pod plans for my new build in Scotland. I did get a site plan drawn as it was around £90 and will double up for de-crofting the house plot. I've some experience with cad and in the building trade. But it's definitely doable. I paid around £350 for a package and just got on with it. Took some trial and error bit I was happy with the result and more importantly then obtained planning consent. And we're used for some of the building control. (In Scotland you need a certificate of design, some were drawn by the structural Eng. I'm sure I saved a fortune.

Edited June 30, 2022 by Jenki
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[saveasteading]

Diy? Yes of course  you can,  if you have the skills and knowledge.

Do you? How do you know that you do?

 

Green roof etc.  I have "green credentials" but never used a green roof where i had control. I would be telling the planners that you had considered it but discounted it on terms of....whatever. In my cases it was usually on the grounds of cradle to grave not actually being justifiable....or maintenace,...or safety.

Fundamentally it requires a lot of extra structure, and after it has grown it doesn't reduce carbon.

Trees are good. Shade in summer. But not the big varieties or the founds have to be deeper.

[spottycat]

Hi - I just thought I'd add that doing your own plans for the planners or Building Control Drawings is perfectly do-able. I did it as part of my DIY Extension design and build. I had so many people requesting it that I eventually made a step by step blog of my entire design and build project including all the drawings and planning application stuff. It's not a commercial site - I have nothing to sell - I created my blog to show what I did and hopefully encourage others that are like minded. If you fancy checking out what I did then please take a look - you can jump to the articles that interest you if you don't want to read the whole thing. I hope it help. Good luck, Chris www.diyhomeextension.co.uk