Cost of converting into double garage

[soprano]

Hello all

Lots of experience on here, I wondered if anybody could give their thoughts on what this would cost:

I currently have a single garage and single brick built car port next to my house, which I am thinking of converting into a double garage. Current lay out is like this:



I want to remove the dividing wall between the two and have an electic roller door installed. I have read a number of posts on here and will probably go for a Hormann, given the number of recommendations.

The left hand wall as you look at the picture will need to have a post built, I would suspect, in order to allow a lintel and the door to be installed (I am no builder so this is just my guess). The right hand wall has a 17cm recess so I think is fine (I have read that the Hormann doors require at least 10cm per side to be installed 'inside' the garage rather than in the gap itself to give the full opening.

The door would need to be in the region of 5 metres wide.

I would also like to have a single side door fitted, to allow entry from the back garden.

I already have a quote for electical work, to include providing the power to the garage door, so it is just the building work (inc or exc the cost of the doors) I am looking to cost up.

Any ideas or obervations welcome. I'm in Cambridgeshire, so any recommendations of builders would be welcome. I know the answer is to get quotes, but it would be nice to have an idea of costings beforehand.

Thanks in advance.

[soprano]

homeimprovements said:

Should be doable. What are you proposing to do with the block floor. ? Where abouts in Cambridgeshire are you?
Regards
Nigel

Hi Nigel

Thanks for the reply. I suspect the best solution would be to lift the blocks and lay concrete so I have an even floor across the whole space. I'm open to suggestions though.

I live about 10 miles west of Cambridge.

Thanks

[soprano]

One more thing I have noticed, the rear wall of the car port area is brick, same as the outside. The rear of the garage, on the inside, is breeze block, like you can see inside the garage on the side wall Not sure if that makes any difference.

[soprano]

LC23 said:

It should be oil repellent whatever he does with it.

I'm going to park on your drive when I have the work done

Anyone any ideas?

[soprano]

I have my first quote and wondered what thoughts are. It is quite a way beyond what I expected:

Quote to:

1. Demolish central dividing wall
2. Reclaim bricks from central wall in order to build two pillars of 300mm x 300mm (reclaiming bricks to ensure a perfect match rather than save cost)
3. Install RSJ across front of garage.
4. Lift paving blocks from car port and lay concrete to match garage
5, Supply and install side door to garage.

Materials: £1560 (I think the RSJ is about £600 of that)
Labour £2,920

Total cost - £4,480

That cost does not include the supply or install of the main door, or the installation of an electical socket for the door which would be on top, giving a total cost of c. £7,000. I do plan to get a couple more quotes but wondered what peoples thoughts were on that price.

Thanks

[soprano]

jason61c said:

What sort of door is going to cost over 2k?

A 5 metre wide electric roller door from either SWS or Hormann, if you have any recommendations for a cheaper supplier I will be happy to hear them.

Edited by soprano on Saturday 9th May 14:26

[soprano]

jason61c said:

4 days work say for 2 men?

A day to knock through and out
A day to fit rsj
A day to do the floor
A day to finish?

2 guys, at 175-200 a day, £1600 tops?

That was more where I was thinking. I know the labourer charge is 120 per day. I would guess the main builder would be more than that, say 175 per day. Working on the basis of 5 days work for 2 men at an average of 150 per day, the labour cost would be c. 1500.

If my daily labour costings are approximately right, 3000 in labour is two weeks of work. I just struggle to see how the job will take 2 weeks.

As for the door, the cheapest quote I have so far is 2,300 fitted but I am hoping to get that cost down a bit, as you say around the 2,000 mark. I'm in Cambridgeshire so any suggestions of local suppliers are welcome.

[soprano]

Spudler said:

I'd say that's a very reasonable price.
+vat I'm assuming.

The builder is not VAT registered as far as I am aware. The quote is definitely all in.

[soprano]

TA14 said:

OK manage it yourself and save £1,500. (Maybe less the cost of those piers and less the cost of taking the blocks up, and less the cost of cleaning up the bricks, and less the cost of a skip or two, and less the cost of.... of course you'll manage the job yourself for free.)

Sorry?

[soprano]

TA14 said:

Basically, if you don't include all of the cost elements, even all of the items of work in this case, that the builder will include then your cost will obviously be cheaper!

Yes of course, but that is not what I am trying to do at all.

I have set out above, from the quote of the builder, the work that needs to be carried out. I am not a builder, but I am trying to work out how much a builder/labourer will charge per day, and how long the works will take so I can get a rough idea what the total labour cost will be.

I am hoping someone who is either a builder or has had experience of having similar works carried out can provide their view of the likely labour costs. My laymans view is that 2 weeks for 2 men seems like quite a long time (if the day rates are approximately right) to carry out that work.

I might be right or I might be wrong about that, which really is what I am asking.

[soprano]

TA14 said:

Take my previous post. You only get to two weeks becuse you have ignored some items and randomly converted their costs into a labour cost. Why not try six days labour, add in the cost of the few items that I mentioned and see how far short of the builder's estimate you come? Then what about the items that we've overlooked?

You seem to be assuming that the only costs are mats and labour

OK try this for an exercise: list out your guess of costs.

(And I'm not impressed with the brick pier solution.)

Sorry perhaps we are coming from different perspectives.

I have listed the costings exactly as the builder has provided them to me. I have assumed the only costs are materials and labour because that is the way they builder has listed them to me. He has put the labour cost at c. 3000.

I am not sure what you are referring to when you say that I have randomly converted items into labour costs and/or ignored items?

And with regards to the brick pier solution, are you saying the way the builder plans to do the work doesn't impress you? If so may I ask why?

[soprano]

TA14 said:

OK try this for an exercise: list out your guess of costs.

Ok I will give it a go:

Materials of 1,560

RSJ - 600
Side door/frame etc 300-400
Skip hire 200
Concrete for floor 300
Other. Cement for brickwork etc 100

[soprano]

Thanks for the replies so far guys, in answer to some questions -

Elanfan - the openings are relatively narrow which at the moment for the garage is ok because the TVR isn't that wide. The car port is a bit of a pain to use because there is very little room each side. I did think about the two door solution but I wanted more room around the cars and I suspect whilst there would be some costs of the job savings, two single doors would cost more than one double, reducing any saving.

There is only one RSJ side to side. I asked the builder whether a second RSJ is needed front to rear and was told it didn't. The wall is effectively built up between the roof trusses. I can take a picture if need be.

Busamav

That is exactly the kind of reply I was looking for, thanks for taking the time -

The RSJ is going to come with a plate welded to it for the soldier bricks as you say. As for sizing it, as far as I am aware the builder has spoken to the fabricator. He hasn't spoken to an engineer for instance. No drawings have been produced.

As for the rear wall and side door, no mention has been made of building brick piers there. I agree there needs to be a reasonable distance from the corner, you may mean from a structural point of view, but also for practical reasons as I would like a work bench/ shelving/ cupboards across the rear.

There are also a couple of other things you have pointed out I hadn't thought of. As far as I am aware there are no sewers in front of the driveway.

Ilovemondeo - can I ask where you got your garage door from? I have a quote from the garage door centre in Northampton which is 2,300 for a securoglide. I tried to get a quote from a local family run company but they declined to quote on account of being too busy!

[soprano]

Busa mav said:

I was talking from a structural point.

The piers each side of the new side door are more to stop the brickwork cracking when the door gets slammed or blown shut in the wind. It's a long pice of wall that would just end at the new frame.

As for taking down the central wall , I suspect that will be a pita, juggling everything through the existing trusses, remembering that they are probably tight to the wall each side of it. It is going to be an awkward job rather than difficult.

Also check that any wind bracing is reinstated / altered as required when the wall is down.

Thanks for your further input - that makes perfect sense regarding the piers either side of the side door and was something I hadn't thought of. As you say the trusses are tight to the wall on either side so I agree the removal of the top part of the dividing wall will be a bit of a pain.

[soprano]

037 said:

I would consider that quote cheap for a decent builder!
Was the builder recommended to you? If so, why not trust him to price what the job is worth to him?
I'm at the point of turning work away unless the customer is prepared to wait till the winter time so I imagine many builders are in a similar position.
As for the suggestions to manage the work yourself, who is going to tooth out the existing brickwork, prop the roof dig the footing correctly, insert the steel, etc....
Following from a thread on a similar topic a while ago, this is a perfect example of why I wouldn't itemise the labour cost on a quotation.
Take a pic of the door for us to see when completed.
Good luck.

This particular builder was not recommended to me - but I do have a second builder who was recommendd to me coming along on Tuesday to give a quote for the work. I know he is busy until September time which is probably a good sign from the point of view of him being popular. Builder No 1 is busy for the next month or so.

Re. the suggestion to manage the work myself, that was made by another poster and I certainly would not even consider it! I am fairly competent as a DIYer but would not tackle anything structural like this. I would probably end up with a large pile of rubble and no garage if I did.

I will of course keep the thread updated in terms of other quotes and pictures of the work if I decide to go ahead and have it done.

ETA - out of curiosity why would this make you less inclined to itemise your labour? From a clients point of view if I could see an itemised quote like the below, (purely by way of example, not that I think this is what this job will take) I would find it easier to follow :

1. Demolish retaining wall, 2 men for 1 day @ 120 per man per day
2. Digging footings, 2 men for half a day @ 150 per man per day
3. Etc etc

By way of contrast I work in a service based industry and am self employed, my fees are quoted based on the total work, but are based upon an hourly rate so if a client wants a breakdown of why X work will cost Y amount I can provide that breakdown.

I am not saying you are wrong in your approach, far from it, but I am genuinely interested.

Edited by soprano on Sunday 10th May 14:23