Garage conversion

doogb

Hi,

I'm looking to get a garage converterd but I've no idea of what the best practises are. The reason for the conversion is so it can be used as a playroom and also to provide extra insulation for an upstairs bedroom, the room needs to be warm enough so that it can be used during the winter.

The size of the garage is l 5.24m * w 2.62m * h 2.65m.
Half of the garage is suitated underneath one of the bedrooms and the other half sticks out in front of the house with an apex roof on it.
It is ajoined to the house and so an opening for a door needs to be made.
3 of the walls will be exposed to the outside.
A wall will need built and a window of app w 2.25m * h 1.56m is needed.

I've had 2 builders look at it so far, one of them gave me an estimate of €7K. I intend to get more quotes.

The first builder that quoted €7K was going to use 50mm / 60mm foam on all walls and plaster board on top of this.
On the floor he is going to put down joists, fill the gaps with foam and cover with plywood.
If there is no insulation in the ceiling he would take the ceiling down, insulate it and put it back up.(This was not inculded in the quote)
Walls and ceiling would be plastered.
He deals with a company for the windows and said it'd be made of toughened glass but he was unable to tell me what energy rating it'd have.
4 double sockets and moving the light switch were included.
He would do the plumbing himself but did not specify what type of radiator he'd use.
Door and skirting would be fitted.

The second builder said he would use 50mm high density foam that had the plaster board already attached to it.
On the floor he is going to put down joists, fill the gaps with foam and cover with plywood.
If the ceiling is not insulated he'd leave the existing ceiling in place and put up high density foam on the ceiling. I presume this would provide some extra sound insulation to the upstairs bedroom.
Reducing the height and width of the room does not bother us.
Walls and ceiling would be plastered.
Door and skirting would be fitted.

My questions are
Is there a preferred type of insulation and the thickness that should be used for the walls ?

Which method of ceiling insulation is best ?

Should any membrance be placed between the garage concrete floor and joists and insulation ?
Is the method for the floor insulation the norm ?
Should the foam thickness should be the same as the joists ?

Is insulation expensive and approximatley how much would I expect to pay for the insulation in the conversion ?

Should a foundation be dug for the window wall ? Wall approx w 2.25m * h 1m

What size radiator do I need for the room ?

What price should I be pay for the overall coversion ?

When you get a written quote should the price be broken down to materials and labour or is it the norm just to provide an overall estimate detailing the work to be carried out ?

I presume an estimate means if there are no unforeseen extra work to be done the estimate will be the final price ?

Is there anything else I should need to know / ask the builder ?

Do I need planning permission ?

Sorry for all the questions but hopefully the more I know the easier it will be to talk to the builders.

Thanks,
Brian.

WAYNE_R2G

been a qualified plasterer and general builder both options sound feasable....personaly i would leave the ceiling as is and screw a new insulated fire proof plaster slab onto existing ceiling thus providing sound, heat and fire proofing....normal insulated slabs would be fixed to exterior walls and skimmed...if your not fussy about the window size, i would call into a window maker and buy a " seconds" window....this is a perfect window made for a customer who never collected it....from my experience of buying this way i have saved at least 50% on price of window ,and i think your first builder is making a few pound for him self here with the window....for your floor securing battens and filling with a high density insulation would suffice...and as for your quote it sounds a bit steep....

BryanF

planning permission may be required