Extension plans- where to start?

[Planning3457]

I am totally clueless and looking for some direction. We have bought a 3 bed detached with a conservatory out the back on one side and kitchen/utility extension behind the garage.

I want to knock down the garage, widen it slightly and rebuild with a 4th bedroom and en suite above, then create a kitchen/living diner out the back using the existing kitchen, utility and conservatory.

Where should be start? Should we do it in one go or get the bedroom first then do then back later? Is it going to cost more to do together or separately?

Do you start with a builder or an architect?

I’ve never done anything like this before and just have no idea!

Thanks in advance.

I would start with drawing some simple plans of my own. Get the tape measure out and see what space you have to work with. Look at your neighbourhood, what extensions have other people done (google earth is your friend). If memory serves you can see planning applications online.

Our local council planning website allows you to search planning via the map meaning you can look at your street or estate with similar style houses and the map highlights all those that have put in planning applications. You can just move your mouse over the property and it shows what they requested ie single storey rear extension etc and I think it also shows whether it has been approved or not from there without clicking into it.

That way you can see if anything similar has been allowed and also whether you can use their plans to influence yours. I knew what I wanted extension wise, drew it up, contacted an architect, they copied my plans and submitted them for me.

Given the mess building works make I would aim for doing it in one go. When we had an extension, we got a builder around first to pick his brain really. He came up with several suggestions and we came up with a compromise somewhere inbetween what he suggested and what we initially thought we wanted. We then got an architect to draw up the plans, submitted to planning and then got 3 quotes for the build.

Brilliant, thanks so much for the advice, much appreciated!

We are on an estate of similar houses but mainly semis or link-detached so not as obvious to extend as ours. The few detached ones there are have the above the garage done and some of the semis are done out the back, we’re on a corner as well so we have the room hopefully.

What is the value of your house, and your budget for the extension? Architects are great (mine is lovely!) but they are expensive. If you work with an architect, be prepared for them to take around 10% of your overall budget. They do add value with great vision and original ideas, but they’re not always great at cost management.

If your budget doesn’t allow, then look at technicians, builders, and design and build firms in your area. They will generally be cheaper.

I got plans drawn up by an architect for £500. They were fine for planning submission but you need more detailed drawings for submission for building regs etc. The builder can quote using planning drawings and often have in house architects or know architects they use for working drawings.

Do it in one go as the plans will be cheaper than doing twice and the building contract cheaper as builders are on site etc.

Agree check local area/ plans as it will gone an idea of what has been allowed by planning

Use a chartered surveyor who is used to doing projects. They will be cheaper than an architect and usually more practical I’ve found, plus many can manage the project/ builders for you (you aren’t doing grand designs)

Do it in one go (or it will be more expensive).

Get the plans for everything done and submit all for planning, then you have x years to do it and can do in 2 stages if you need to.

We used an architectural technician as what we wanted was fairly bog standard box ans some internal remodelling... he is well used to drawing them for planning and building regs. He also ran the tender for builders, it is £120k what we are getting done so it’s a fair chunk we are paying him.

We had an idea and he came round and gave us some other ideas and pointed out things we hadn’t noticed like a window that would have to be made smaller and a better idea for a use of space.

He also liaised with structural engineer for steels and calculation.

He also recommended builders. We’ve used him before and was originally recommended by a friend.

We also had a builder we’d used before who came round and did a back of a fag packet estimate before seeing plans, that was about ££20k out but gave us an idea.

For a project that large, I'd use an architect. Ask found for recommendations or look at their websites to see their projects. Probably easier to get it all done together - less mess and might be cheaper as the builders can do various bits in one go. If that is not feasible financially, the architect can help to break it up into a couple of stages.