Rear Single Storey Extension

[Toooldtoworry]

Is anyone else considering one, or recently had one done?

We've got the architect coming out today to measure up in readiness for his plans to submit to building control, and we know what we want to do. Just wondered if anyone has any tips.

For reference we currently have the kitchen at the front of the house (small) and we are going to move the kitchen to the lounge to make it a lounge diner. Convert the kitchen to a utility/cloak and the extension will be the lounge as all drainage is at the front of the property this is the easiest solution.

I'm a bit nervous about the cost, but moving would mean for the property we would want we'd be looking at another £170k before moving costs and the extension I am expecting in at half that at least (we do have other work we want finished).

I think 85k sounds on the low side for what that work would cost, but maybe it’s where I am in the country. Have you had a builder quote?

unless you are going to project manage, you will be very lucky to get under 85k for that. Prices are shocking. If you do get a lower price, be really really careful in stipulating your expectations and finish. In fact, do that whatever the price!!

Ok, builder has quoted for the extension 47k, so I wasn't expecting another 47k on top to move the existing kitchen (possibly small add) and put a toilet/shower in the existing kitchen.

South West area.

We're at the back end now of a rear single storey extension. Not knowing how big yours will be and all the details, I'd say £85k would be ambitious as all the bits really add up For instance the steels in mine, in 2019 would have been £10k, by the time they were installed, over 20. We had to do a new fuse box/ consumer unit as once they touched the kitchen it had to come up to standard and then it turned out our wiring was really weird and needed quite a bit of time to sort out. Once the extension was in place, we needed fire doors to the kitchen which added cost.

If your budget has to be what it is, watch out for all the creep that its easy to add on, or the spec of items. Our surveyor comes once a month to sign off what has been done and agree how much we pay each time but its a bit late by the time thats done to discover you said yes to tiles that were way more that planned for, or the cost of plaster had skyrocketed

Just as a warning, we were quoted ballpark £40-£50k pre building regs drawings from three builders. After the building regs specification, we have been quoted between £78k to £120k, shell finish only, and to purchase our own skylights and glass doors.

There was only about 3 months in it, so it wasn't the timings I don't think. We've decided to bite the bullet and go for it, but the architect was also meant to be working to a £50k extension shell budget

Thats a cheap price for the extension these days, what finish are you taking it to? Brick or plastered and electrics etc and ready to roll. Depends I suppose , most people usually get fancy new kitchen but if you are moving your current then obviously cheaper.
Just DO NOT start until you have it all priced out to finish or to a level you can do yourself. You will be really suprised how much things add up quickly! So many suprised can pop up and you need to make sure that all your drainage works out before you start. Even price up flooring and fitter etc. I can’t stress this enough… price everything then add 20% buffer. If you can afford that, go for it.
Do you know tradesmen that are going to pop in on a day rate and sort you out a downstairs toilet or are you going to end up with a plumber quoting you 10k etc.

The price of labour and materials are very very high atm and sorry to be negative but we are on the back of a monumental run for builders in terms of plentiful work. When people are crying out for services, standards drop. Why care about reputation if the moneys pouring in and you get work regardless? I have seen this happening with my own eyes. Easy money for builders… just make sure that your hard earned money goes not become their easy money.

We’ve had a single storey rear extension to make a kitchen diner family room and have moved location of kitchen (not from lounge just from its normal place into the new extension). It has cost us £40k all in.

Have had architect out today to measure and get the plans drawn up to send to building control as we are doing a 6m x 3m with a pitched roof. I have had a ball park figure of 48k to take it to ready to live in (ie walls plastered/painted/heating installed/electrics/flooring installed) but know that may increase when we have the final plans and are prepared for more but I think we'll be hard pushed to raise more than £100k.

I sound like I am being cheap when repurposing, but we only moved in 3.5 years ago and we have had to have a new kitchen installed in that time that I still like, sliding patio doors are less than 6 months old and can use them for the rear doors.

There is some plumbing, but it is not major and we purposely not moving the kitchen to the back because that would add 15/20k to the bill.

I work in mortgage finance so am aware, as you said, to price everything to the nth degree and to add an extra 20% tolerance.

Re: the build I expect we will get the whole lot done by the same builder IF it is cost effective to do so. I am happy to buy the items needed direct if it saves money but we don't want anything fancy in the downstairs shower room and definitely won't be spending 10k on it. We already have the flooring because we ordered it when it was on sale (completely waterproof LVT)

@CMOTDibbler we don't actually need steels thankfully because there are already lintels where we are taking out the patio doors and the window and we are leaving a pillar in to mount the radiators (sounds stupid but actually looks right). Steel is BLOODY expensive.

We've also already uprated the consumer box when we had the kitchen done 3 years ago (ish), got fire doors in place already so there is some of the cost already spent if that makes sense.

Honestly, we have already done so much to this house this is just the final push. IF it comes back much more than we are expecting we will just have to hold fire for another year or so.

Sounds do able then. But like I said, get a full quote from builder for whole job finished to see where you are at. Good luck. Don’t make the mistake of being scared of the builder of gaslighted about what normally happens. Make sure you sign a water tight contract with everything he is going to provide and do for that price. If he shirks out of that, pick another builder!

Thanks @Gobleki

Also… check for the builder on companies house. Type his name into internet with town you know he lives in and check to see if he’s registered and has history etc. if a builder is telling you he’s been trading for years but is showing as only trading with that company for a cpl, what happened to his last company?
you would be suprised what a good trawl through companies house will uncover about tradesmen.
check out internet for reviews aswell

One more thing. Be around! Unless builders are used to working on projects where they have sole responsibility for passing them through building regs, they can and do get lots of things wrong! Don’t let it happen, be involved. Be there when building inspector comes, be there and present , communicating as much as you can. Also discuss and get contracted , who pays for mistakes. Builders love to quote prices to finish then make mistakes and try to add them to your price! Discuss this with the builder first!
Discuss that the builder cannot do anything that adds to the total without discussing with you first.

Good point. I am home, but I'm a financial adviser so rarely 'around' if that makes sense. I'll make sure contracts state builder pays for their error.

How many metres squared is it? We were quoted £80k for a 30m2 upstairs extension. Still cheaper / less hassle than moving but I can't get my gears around the price! 4 years ago we were quoted £40k!

18sqm

To be honest we've got a conservatory in its place at the moment that is 6m w x 2m d which is leaking and a dumping ground because you can't fit a dining table in it which you can sit round, or a sofa widthways so we have to do something. I just feel that a conservatory would be a total waste of 25k when we'd eventually have to redo (we're going out of here in a box).

@Userxyd sorry that was in reply to you. Why does the reply button not work?

No worries I'm not on that often anyway!
Have you got any clearer costs/plans now?
if you're going out in a box and have a leaky conservatory to replace as well then that's two solid reasons to go for it.
Cost of moving is horrendous and a deadwood cost on top of the cost to buy a new place, renovate it and all the stress and hassle and uncertainty of being somewhere new.
We're trying to console ourselves with that anyway! We've never spent much on renovations either so this would be our big do up and then we can enjoy the house.

Ours was circa 130k for a 7 x 5 metre extension but it largely depends what you are having in it. We have had large sliding glass doors for example, under floor heating, large steels, aluminium pressings and roof lights etc
Absolutely worth it though as we couldn't move anywhere and get what we have now.

That doesn't include the garden which was destroyed in the process and we had to redo to gain more patio area.

£47k seems very cheap OP. I had a rear single extension of a similar size 12 years ago(not used as a kitchen, so no expensive fittings) - and it was £55k. This was in the north.

18m3 x £3000 is £54,000. So these days, that’s the minimum. Materials chosen can make a big difference. Plus making good to garden. The internal works will be around the same money I think. Personally I think 3m x 6m is too narrow for a lounge. For permitted development, can you not get more depth? This room is too shallow to be easy to use. I’d spend more and get a better shaped room,,

No, we can't go deeper under permitted development but an extra 3m on the current lounge makes it 7m deep in total.

We are still waiting on architect drawings before tendering out to builders, but initial quote as a ball park was just shy of 49k not including VAT. We don't need steels because we are not taking the entire back wall out - just the window and patio doors which already have concrete lintels.

Garden shouldn't cost much to fix - although we know that it's going to get churned.

Kitchen is not going in the extension its moving one room down so all drainage/waste will be internal extension of pipework, no requirement for digging up outside.

@mumneeds spending that doesn't frighten me. If we moved we'd not get the same space and we'd be an extra £200k spent.

@Toooldtoworry I see. The lounge will be disjointed though with walls left and a radiator in the middle of the space. (I think that’s what you are describing) Each space will be separate and won’t feel like one room that’s 7x6m. Personally I’d open it out. Two strips of narrow rooms isn’t really a lounge. The overall space is not enormous!

You are right though, you won’t get a conservatory you can live in all year for £25,000. Your price with vat added isn’t far out for the extension. I would hope your architect has better vision of space though. That’s what you are paying for or are they not a chartered architect? Just a plan prep company?

This room is only 23ft x 20ft. So keeping walls in and opening up windows only might make it odd regarding usable shape. Too many barriers.