How do you start knowing what it might cost to renovate?

[Ilovesnacks]

It's so hard to even know what to budget for. How did you find out? Did you have a budget in mind and work to it? Did you ask neighbours? Is there some mysterious AI app that can work it out for you? It's all so cloak and dagger.

For context we're looking at a 1930s house (London 'burbs) that would benefit from a converting the kitchen + dining room into one. We'd ideally also want a small, say 3m extension. It'd also obviously need the kitchen units itself, new flooring to all downstairs rooms, any bifold doors, new radiators or underfloor system and structural engineer fees and so on. I just don't know what to expect.
Also I assume most people take the capital needed for reno work out of their deposit?

Could you ask a builder to come and view it with you and give you a quote? Then add a margin!

We had a certain amount in savings from sale of previous house. So knew we could afford some work. Day after completion we got builder in to quote. That was fairly broad quote but we could afford it so went ahead with builder who then did a more detailed quote. At that point we had to cut some things back to make sure we still had some contingency available.

Ask a builder to come and give a quote. But then add in a massive contingency! And yes we used some of our deposit money for renovations.

Ah thank you. So - just checking I get this straight - once the sale of your current place goes through to completion, the solicitor holds the cash, but you request X £ to be held back for renovations.... and so any remortgage amount on your new place is based on what you removed from your deposit? Did it ever feel reckless doing that (guess it's the only way people can do it - I'm just naive). Thanks

We got a ballpark figure to redo our kitchen from a builder. Now we have actually chosen a kitchen and he came back to do the quote, the price doubled and we can't afford it.

Annoying as we'd got the party wall stuff done already, which will expire by the time we save enough to actually get the work done again and will need to be redone.

Ah great thanks @RidingMyBike - did you use an architect at all? And dare I ask what % contingency you found you needed?
Asking now because we'd need to hold some deposit back from our sale and so need to ascertain how much we'd need to borrow on the mortgage. Thanks

We kept some of the equity from our sale to do the renovations as well (we also took the SDLT for our purchase as well out of it) - I don't remember ever telling anyone this though!

Although in hindsight, we didn't keep enough!

You want to decide the layout of the proposed kitchen. Get a quote (or maybe 3) for the building work, flooring, electrics and plumbing, having decided where you need plumbing for the kitchen, sockets and lighting. Look at the kitchen from kitchen suppliers and their installation costs, think about if you could install most of the kitchen yourselves, kitchen installers can be rubbish. Contingency should be 10%ish, but if you haven't done your homework and need lots of changes to what you initially got quotes for it could be much more, stick to your original plan and there's not so much scope for builders upping the price.

Hi OP, just sharing a lesson learnt in case of use to you...

If the decor is tired and dated, if nothing much has been done for 20 years or so, then you will most likely need to upgrade/renew ALL the wiring and electrics and possibly the heating and radiators!

Also consider windows, roof etc.

We thought we were budgeting for painting, carpets, kitchen and bathroom, plus extension costs - in fact we went back to bricks to completely re-wire and re-plumb the whole house which more than doubled the cost of our initial guesstimates.

Don't regret it - the house is gorgeous now and we'll be here for years - but we will be repaying the overspend for a good few years yet :(

So it's worth checking those basics - get a knowledgeable person to cast an eye over the electrical consumer unit, and the boiler, radiators, etc - before you think about the extension!

Apologies if it's not at all relevant to you and the house is in good nick apart from the extension, in which case ignore! :)

Also, for what it's worth we got our technical drawings done by a RICS chartered surveyor who charged us about £500 IIRC - this allowed builders to quote in detail and was useful for getting building regs sign off etc. If it's a simple case of moving a few walls you don't need to pay architects ££££ fees.

Best of luck!

Didn't use an architect - we had a structural engineer produce drawings and do the calculations for steels/supporting walls.

I think you'd just talk to your solicitor about the amount you need transferred to you rather than passed on to the house seller? And make it clear to the bank what the deposit amount is. We sold, went into rental, then bought months later so the whole equity amount was transferred to us and we just kept back what we needed for renovation when we bought.

First time we did this we had 10% contingency. This time we decided on 15% as there was so much uncertainty about cost of materials. Even the oven we chose went up by about £300 then disappeared from the market entirely in the space of a few months.

In the end we needed 9% contingency so it worked out fine but try and get as much specified in the detailed quote as you can as even simple things like door handles, tile trim or light fittings really add to the costs. That then reduces the number of unknowns you're dealing with.

£2000 per square metre is a good guide for the extension.

bathrooms £10k +

Thanks @MrHopsPortal as I see it we have two options.

1. Keep budget back from the sale mortgage the rest - but this is at the current very high interest rates.
2. Don't take from our sale budget. Wait a few years and remortgage in line with when our current mortgage will also expire. The logic being by then, hopefully we'll see calmer rates and will have had chance to pay down a bit more. I can't tell what's more risky though...

@WoolyMammoth55 Thank you so much! And this has made me think we should probably get an electrical survey done. Christ, I never thought we might have to go back to brick for that so yeah.
Interested about your rec not to use an architect too and instead get a surveyor to do technical drawings. Playing devil's advocate, isn't the point of an architect also that they control the budget and timeline and tender the building work, as well as of course, designing a layout with things you might not have thought of?

I shouldnt expect much change from 100k from what you've written.

One tip - things that look "fine" when a room is run down look awful and old when the rest of the room is newly renovated. Rip it all out and go from scratch

Consider paying a kitchen designer. Now i have a well designed kitchen i am shocked at how poorly designed a lot of kitchens are.

Don't buy cheap flooring.
We laid amtico downstairs but put LVL tiles in the kitchen and utility. The lvl tiles i did all the right things. I got samples and tested their resiliance and put them on the floor and we walked on them for months. We laid them and they are crap. They make me angry on a daily basis and we are going to replace it with amtico next year (which is amazing). And it only saved us about £500. Total false economy.

@Totalwasteofpaper Oh I thought Amitco was LVL, it was just one brand within the category of LVL. Agree it's better quality though.
We have had some quotes come back and costs to renovate look more like 180k minimum.... we have friends who live on the next street in an identical house and have just had quote of 30,000K to extend one ground floor room, redo bathroom, windows to 4 bedrooms, small bit of landscaping near the extension area and to renovate the house's entire heating system. They can't do it.

300,000* not thirty thousand - typo!