Partial Garage Conversion - Advice on costs

lokz

Hello all,

We are planning to do our integral garage conversion some time this year. I have been doing some research, getting help from this forum and have also got multiple quotes which helped me finalize what I wanted in terms of the garage.

Our house layout below ( 3.4 m of back of garage is part of house and there is a room above it.  2 m of front of garage is single brick wall and there is a flat roof above it )

Proposed Conversion picture below: (Border measurements inside the garage)

The garage space which needs conversion is 2.6 m * 4 m

Garage Picture ( as taken from front of the garage)

Flat roof of the garage (taken from a bedroom)

This is our first project and I always taught the project would be less than 10K excluding the units as it is an integral garage and I am only converting it partially keeping the front as it is . As it is an integral garage ( the common walls are double bricked and there is cavity insulation done by previous owner)


I have started getting quotes and the quotes varied from as low as 10k to as high as 20k but most are  between 12 K and 14 K for the above layout. I was surprised by the cost.

From my research this is what I found are the costs (  labour and materials ) - All done according to building regs. The area will be 4 meters length by 2.6 meters width.

1) 1st studwall with fireprotection at the front of the garage - 1000
2)  2nd studwall for the bathroom with door - 1200 ( door supplied by me )
3)  Creating a new opening from the hallway into the garage and fixing a lint and fitting a door and finishing it properly - 2000 (door supplied by me)

4)  Removing existing window and  Supply and fitting a new double glazed window in the place ( 120cms  * 90cms window ) - 700
5)  Boarding and Insulating the internal walls and floor -  2000
6)  False ceiling - 1000 ( not sure if this is required )

7)  Plumbing and Electrics - 4000 ( The electrics are already present in the garage , so I undestand most work is plumbing for water, waste and CH . The waste pipe runs just  on the side of  the garage. This also includes fitting all shower room units , electric fixtures and radiators)

8)  Misc - 1000

I think I have been liberal with the prices above. I think I am okay with 12000, but 14000 I feel its high considering the size of the conversion . I need perspective from others so that I feel I am not being ripped off for such a small space.

The space is important to us even though it is small, because it will add a second bathroom in our 3 bed home (with 2 young kids) and also gives some extra space

On the side note. I am planing to replace the garage roof with GRP and size of the roof is 8 sqm .Any idea how much does this cost.

Also from what I read, most of the integral garage ceiling is with asbestos (My house was built in 1970s) . If building control officer doesn't flag it , Should i raise it with him or not?

Also how does the contract works when i start this kind of project. Can some one give me a quotation for 13K and charge me 16K at the end ?

Others knowledge will really help me now, as I do not have any first hand experience in a project like this. Thanks for your time everyone.

Doozergirl

Why aren't you converting it properly and adding the value to your house by adding a window at the front?  You're spending that much anyway, do it properly and reap the reward.  

I think you're missing a trick with the design.  Access the bathroom from the hall and make this conversion feel like a proper part of the house.  It gives flexibility to the front room as well for the future.  

As it is, you're creating a glorified hallway for the shower room with a weirdly placed, undersized window that faces a brick wall.  

You're allowing the existing layout tail to wag the dog, yet you're buying a new window anyway.  Buy a bigger one and put it on the correct wall! 

As far as contract payments go, have a proper contract in place and that will lay out what happens with extras.  What you need is a full written specification to start with, so it becomes clear what is included and what isn't.  That is how you get directly comparable quotes.  

There's a part of this guide that details what should be in your contract.  https://www.fmb.org.uk/find-a-builder/ultimate-guides-to-home-renovation/how-to-choose-a-builder.html

Section62

lokz said:

Also from what I read, most of the integral garage ceiling is with asbestos (My house was built in 1970s) . If building control officer doesn't flag it , Should i raise it with him or not?

Building control wouldn't normally be interested in the asbestos, unless it was left in a state which posed an ongoing risk to the health of the occupants of the building.  If you use LABC there is a chance the BCO might contact HSE to report unsafe working practices if they see them, a private BCO might also do that.

The risk for you falls into one of two categories - assuming the ceiling is asbestos.

1)  The builder ignores the asbestos and gets on with the job.  They can't do it properly without disturbing the asbestos, so your property gets contaminated with asbestos fibre. They leave the bulk of the asbestos in-situ, which becomes a problem for you if you need further work done as removing asbestos from (say) a bathroom which can only be accessed through the house is more complicated (read: 'expensive') than removing it from a garage with direct access outside.

2) The contractor starts the job at the quoted price, then 'discovers' the asbestos and has to stop working.  You then have to arrange for the removal of the asbestos (at your cost) and the builder asks you for more money to cover their costs while they weren't able to work. You refuse to pay more, so have to find another builder to complete a half-done job.  Or you end up either making a financial claim against the builder (arguing they should have known about the asbestos) or the builder claims against you if you've refused to pay (arguing as client you were responsible for telling them about the asbestos).

So the sensible way forward would be to get the ceiling tested and if it is asbestos arrange for a competent contractor to remove it before the builder starts work.  That way you know it has been removed properly and safely, and that it won't create any 'complications' to the build.

In terms of costs - small fiddly jobs tend to be disproportionately more expensive than larger simpler jobs.  Complicating things by wanting to supply some of the stuff yourself adds to the 'fiddly' factor.  Builders want to get on with building, and will order what they need so it arrives not too soon and not too late.  Having to co-ordinate purchasing of materials with you makes the job harder, without any substantive saving.  This complexity also adds risk to the project - e.g. if your materials don't arrive on time - and the builder is likely to price that risk into what they quote you.

jonnydeppiwish!

As DoozerGirl, convert the whole garage fully with a window at the from. You’ll benefit much more from the whole process and gain a lot more usable space.

You’ll end up with a decent downstairs bathroom and a study/playroom etc. 

With regards to the asbestos, it that actually in the plaster/artex or was it just a possibility in the survey?

stuart45

jonnydeppiwish! said:

With regards to the asbestos, it that actually in the plaster/artex or was it just a possibility in the survey?

It was really common back then to use AIB for integral garage ceilings, so there's a good chance of it.

lokz

Doozergirl said:

Why aren't you converting it properly and adding the value to your house by adding a window at the front?  You're spending that much anyway, do it properly and reap the reward.  

You're allowing the existing layout tail to wag the dog, yet you're buying a new window anyway.  Buy a bigger one and put it on the correct wall! 

The main reason is to use space under up and over garage door to store our bi cycles and Garden equipment. Don't want to buy a shed as our back garden is small. Although we have a 11 feet front driveway/garden in front of the house.

I think you're missing a trick with the design.  Access the bathroom from the hall and make this conversion feel like a proper part of the house.  It gives flexibility to the front room as well for the future. 

As it is, you're creating a glorified hallway for the shower room with a weirdly placed, undersized window that faces a brick wall. 

If we access bathroom directly from the hall, How do we get into the new room? Current window needs to go anyway as will fail building regs. It has to be bricked up or a new window needs to be replaced, Will think about definitely bricking up the garage with a new window. Every one seem to be suggesting it.

As far as contract payments go, have a proper contract in place and that will lay out what happens with extras.  What you need is a full written specification to start with, so it becomes clear what is included and what isn't.  That is how you get directly comparable quotes.  

There's a part of this guide that details what should be in your contract.  https://www.fmb.org.uk/find-a-builder/ultimate-guides-to-home-renovation/how-to-choose-a-builder.html

Thanks for the link. Will definitely take this advice. Couple of friends who got their building work didn't suggest their builders as they said it was nightmare to work with them. All the good reviews on Google seem to be very expensive or very good in a specific Job ( bathroom fitters / Joinery ) . Don't know why people doesn't suggest Checkatrade. I understand they hide negative reviews. It's  very hard to find some reasonable builders whom we can communicate with.

lokz

Section62 said

In terms of costs - small fiddly jobs tend to be disproportionately more expensive than larger simpler jobs.  Complicating things by wanting to supply some of the stuff yourself adds to the 'fiddly' factor.  Builders want to get on with building, and will order what they need so it arrives not too soon and not too late.  Having to co-ordinate purchasing of materials with you makes the job harder, without any substantive saving.  This complexity also adds risk to the project - e.g. if your materials don't arrive on time - and the builder is likely to price that risk into what they quote you.

All the builders/tradesmen in their quote said that I need to supply doors, wash room units and tiles. I will not be supplying anything else.

lokz

@Section62 Thanks for the detailed explanation regarding asbestos scenarios. I will keep that definitely in Mind .

@jonnydeppiwish!  @stuart45  It was in my building survey couple of years ago which suggested, there is a possibility of asbestos in ceilings and roof boards due to the age of the building.

Also when i started researching about integral garage conversion, I read many bad experiences regarding Asbestos.

Hence little bit concerned.

Rewiring of the house was done in 2018 by previous owner. You can see the new switch box and electrical supplies in the garage. Not sure if they had replaced it or just painted over it.  I have some pictures for the garage ceiling and there seem to few fixings to it as well. Can't say by touching what it is . Have attached the pics. Have attached a pic of the roof board as well.

What would be the cost price to get the house for asbestos tested?. Also How much does it cost to remove the asbestos if found in garage? . Thanks .

lokz

Does any one know, how much cost does it add if we go ahead with the Garage conversion by bricking up the wall and adding a window. I understand this would mean  2 meters of extra insulation on both sides of the wall , on the ceiling and floor in the front of the garage. This would mean , the stud wall cost can be deducted from my previous quote.

From what I understand it can come  to 15K + cost of white goods and tiles ( shower unit, basin/vanity unit, Toilet, Wall and Floor tiles)

I am thinking long term as we only bought this house 2 years ago and no plan of moving for at least 15 years . I am thinking of adding a pitched roof to the garage. I know its add to the costs, but I am planning to replace garage roof  anyway. Any idea how much does it cost for 10 sq meter new pitched roof? . Thanks everyone.