Ground floor extension first, then building above

(27 Posts)
Hiphipho Wed 01-Jul-20 16:26:32

Has anyone done a double storey extension in two stages due to cost?
We need extra space downstairs plus extra bedroom but can’t afford £100k + in one go as would be remortgaging to finance it. So were thinking of doing rear kitchen extension first, then eventually building above once we can afford to.
I appreciate it would likely be more expensive overall with the roof etc..
Has anyone done it this way? And how much value did the single storey add?

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sianyb83 Wed 01-Jul-20 16:47:14

I know someone who basically got everything to first fix for 50k, (was quoted 100k for 2 story extension inc kitchen)
So the upstairs was just a shell, but watertight.
3 years later they finished the upstairs...

Hiphipho Wed 01-Jul-20 16:52:46

Wow that’s long ago was it? Think it would drive me mad looking at the unfinished rooms upstairs but I guess it would be good motivation to save!

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Hiphipho Wed 01-Jul-20 16:56:23

After first fix (is that plastered finish?) there would be..electrics,kitchen/bathroom, flooring, tiling, I missing anything else obvious to finish??

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worriedmama1980 Wed 01-Jul-20 17:11:47

We looked into it and it was much more expensive broken into stages than doing it all at once. 100k for everything vs 70k for first stage (you need more expensive foundations and other things for something that will become double height) then something like 50k for second. We found the extra money which I appreciate isn't an option for everyone and cut back v much on finish- basically we got tbe double storey shell and did all painting flooring kitchen fitting etc ourselves to save as much money as possible.

Hiphipho Wed 01-Jul-20 17:40:30

Thanks for that, that’s what I feared. It does seem abit pointless paying for a roof/sky lights in extension bit to rip it off again too. When you say ‘shell’, what finish was it done to? How much did you budget to finish it all off yourself, if you don’t mind me asking?

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Africa2go Thu 02-Jul-20 00:34:23

Similar situation in that we got permission for a double storey wraparound extension. Got quotes and couldn't afford to do it all, so just did a double storey rear extension. I can't remember the numbers exactly but it was something like £40k extra to go out at the side. 4yrs on and we've just got quotes for a single storey at the time, and its £40k just for the single storey at the side now.

Its really tough. I wouldn't have wanted to compromise on finishes / kitchen etc when we did the original extension so we just couldn't have done it. We really couldnt have found that much extra. However, i'm gutted that its going to cost so much more to do it in 2 stages (not even sure we'll go ahead).


Rhica Thu 02-Jul-20 01:27:58

We are doing ours in 2 stages. I wonder if the increase in prices in prev comments reflects more the increase in building costs over time rather than extra costs for doing it in 2 stages if that makes sense.

I told the builders our plans to extend again in the future so Our foundations and roof in the extension have been done ready to build on only additional/wasted costs incurred would be the roof finish and planning application. Maybe I'm being overly optimistic though

Advantages of doing it this way is reduced disruption. But then... Will be two lots of disruption so maybe that isn't a plus

Hiphipho Thu 02-Jul-20 06:11:19

Rhica - would you mind sharing what quotes you were given for the single storey recently and size?

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AbitObsessed Thu 02-Jul-20 08:21:34

I'm just about to embark on a single story extension. We weren't sure about a double story and decided to just go with the single, however our plans and build will include steels in place if we ever want to add a room over one side of the extension. The price has come in a lot higher than expected for the single extension, but we decided to keep the steels. They cost an extra £800 or so, but would cost triple that to pit in place retrospectively. We may never build that extra room, but we have the option and it'll be a bonus if we ever sell.
I think building up would only have been less than 50% of the cost of doing the ground floor.
My advice, put the structural work in place now because it'll be more expensive and more disruptive than later.

On another note, we aren't putting skylights into the room below where we'd add the upstairs extension, but kept it above our kitchen only which could be impacted by a reduction in light from the upstairs room. Hope that helps

weepingwillow22 Thu 02-Jul-20 08:22:37

I don't think you will save that much doing just the ground floor first. The footings, roof and finishings are the expensive part, all you will save is an extra few couses of bricks and the upstairs windows.

If you can't afford to do it all I would either wait and save, compromise on the finishes or like others have said get the first floor watertight/to first fix and leave it to later.

Are you planning on adding a bathroom upstairs? If so this is where the upstairs cost will mount up. An additional bedroom is relatively inexpensive.

To give you an idea of costs we are currently doing a 2 storey, kitchen with bedroom above of 64m2. The total cost excluding the kitchen and flooring but including vat is £110k. If we just did the ground floor I think it would be about £80-90k. Our build has a lot of steels and glass and we are in the SE so you could get it cheaper than this.

twoglassesofprosecco Thu 02-Jul-20 08:31:33

We're doing it in two stages. We did the single storey ground floor kitchen extension five years ago with a view to adding a large en-suite bedroom above. Awaiting planning for the upper floor now.
Kitchen cost £30k including foundations to take a second floor, downstairs loo that has pipe work to go upstairs to en-suite, and the roof of the kitchen will be repurposed above the bedroom, plus the kitchen roof joists are suitable to be a floor for the bedroom.

It's a shame we couldn't do it all at once, but money...

Baxdream Thu 02-Jul-20 08:39:56

We did a large double storey 3 years ago. We did it in one go.
Could you do it as a shell upstairs and leave it?
We remortgaged twice during it. We got the initial money then got the house valued once the downstairs was done and got more out to finish it. You could do that?

Rhica Thu 02-Jul-20 10:29:17

@Hiphipho are quoted were 47k, 53k and 79k for a 7m x3m extension. That's wall in (ie finished with kitchen and decorated)

We actually went bigger with a 10m x 3m plus half garage conversion. This was far more complex and required huge steels as we removed the corner of the house. Our quotes were 53k and 69k.

We are finishing in the next week and will end up spending 65k. Mostly due to upgraded kitchen and 4k for additional roof costs.

Hiphipho Thu 02-Jul-20 10:38:34

Baxdream, how much value did the finished downstairs add for you? I think that’s a good idea actually, hopefully doing it that way it won’t be unfinished for too long.
Really don’t want to compromise on the kitchen extension, although won’t go mad with the spec it’s probably a once in a lifetime thing for us to have it exactly how we want it do don’t want to scrimp and regret anything!
Are you happy with how yours ended up?

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Hiphipho Thu 02-Jul-20 10:43:57

Rhica - what part of the country are you in? Your quotes have given me hope actually!

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Loofah01 Thu 02-Jul-20 10:55:39

Yep, me! Wen't to architect and asked for plans with budget of 150-200k. Lovely plans, great in all respects but one - the actually quotes were double expected. Made some changes but still having to do in two build phases. The plus side is the learning from first phase!
We made sure that we spent extra in phase 1 to make sure phase 2 would be simpler - added pads for the steels and put in some steels now instead of later.
Phase 1 has probably added what we spent, phase 2 will add about 3 times the spend.
Because each builder has a different idea of finish, I'd suggest getting quotes for build up to 1st fix (walls n shit), and the 2nd fix just cost for fitting based on what you supply. It means you spec the bathroom, kitchen, floor covering, doors and fixing etc but there's no interpretation required - you get what you expect, not the builders liberal interpretation of a high end finish which is a basic spec from Wickes.

Hiphipho Thu 02-Jul-20 11:05:15

Great tip about second fix fitting only thanks!
How much on average should drawings/plans cost??

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Rhica Thu 02-Jul-20 11:37:58

Based in Chester. The quotes were for lower spec. Think laminate floors and 4k kitchen. I went for this to eliminate mis-interpretations as @Loofah01 has mentioned above.

We took a gamble and went for the cheaper builder. His work has been spot on

tentative3 Thu 02-Jul-20 20:47:55

Rhica if you would recommend the builder would you mind pm'ing me his details?

Tubbyinthehottub Thu 02-Jul-20 20:58:41

Yes, we converted the garage and had another garage built on the side. Then a few years later built on top of the 'garages' and also did a kitchen extension. It was more expensive but that's how it happened. No idea about value but it was worth it for us to have the living space we wanted.

Georgielovespie Thu 02-Jul-20 21:37:05

You are only saving the cost of the second storey walls and a window so I would look at getting more quotes to do it all in one go. You already have single storey walls and the cost of the roof so how can it cost so much more?

Our builder charged us a daily rate but told us how long it would take and was true to his word. He rang the builders' merchant and we paid them directly, same with all the sub-contractors, plasterer, windows people but all of that was covered in the original quote so we knew what we would be paying and to whom.

It meant he was under the VAT threshold every year as he only charged for his labour, no other money went through him. He invoiced me every week after he had worked the 5 days and then I did a bank transfer whilst he was having a final cup of tea for the day. He is no longer doing building work so I can't even recommend him to anyone.

Source your own kitchen and get them to fit it, that is what we did. I shopped around for everything appliances, worktop etc etc to cut costs wherever I could.

Baxdream Thu 02-Jul-20 23:17:10

We were really happy with it. Ours was £120k all in including kitchen etc. Ours was large about 7m by 5m double storey. Ours was probably worth 330k pre build and it's now £485k

mumdone Fri 03-Jul-20 06:20:19

@Baxdream this is exactly what we are doing. As lenders are loaning large LTV so the price needs to go up!

Baxdream Fri 03-Jul-20 08:37:53

You just have to make sure you do the big parts that add the value first and don't make it unmortgagable ie make sure the new kitchen is in and plaster etc
Plus have a great mortgage broker

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