To think I can design my garage extension without hiring an architect

[Pavementworrier]

Or am I kidding myself

I'm sure architects didn't used to be a thing normal people ever had to hire

We did a rear extension without an architect. We dod have a structural engineer visit but other than that had a good builder!

A loft conversion with an extension is more complex than a garage extension, which presumably, is a simple increase in footprint.

I’d imagine there are still structural loads to be calculated

My friend did this when applying for planning permission and it went well!

It’s all dependent on the size, but a simple single storey extension will generally not require calculations and a competent builder will have a working knowledge of spans, openings etc and when to involve an engineer.

Don't waste money on an architect! A lesson I unfortunately learnt too late.

Don’t skimp on this stage it can be costly

Don’t assume you can trust your builder - they will likely design what they want to build

Professional drawings maybe needed by the planning and building control depending on what you are having done and any restrictions on your property/area.

If you sell your house and the work you have done isn’t correct it can cause problems and result in a lost sale

Do you need to meet building regs or get planning permission? Do you need any expertise for either if these?

We used an architect for an extension, which was very similar to an extension that our neighbours have. We initially thought it would be sensible/cheaper to ask their architect to do the drawings, but we couldn't get hold of him, so ended up with our own architect. I'm really glad we did as our architect suggested a few other things and we've ended up with a better extension.

No expert but garages can be single skin possibly, rooms need a different spec and insulation.

If you want to sell the house, you need to provide proof that the extension has been approved by the Council Building control team. So I would start with a phone call to them to ask what’s required for your ‘vision’. You may consider it a faff, but it’s a whole load more faff if it’s not compliant when you want to sell it (it has to be done retrospectively, takes time and won’t sell until it’s done)

We did a loft conversion. Hip to gable plus dorma. No architect but I did a set of drawings myself to show to a planning officer to double check we were within permitted development and to communicate to the builder. We did pay for an engineer to calculate steel size etc but that was a fraction of the cost of an architect.