Hi

We're in the process of house hunting and have come across a nice
place with room for improvement.

The property is about 20 years old and has an attached double garage.
To make more upstairs space I would like to build on top of the
garage.
The owner reckons the existing garage foundations are good enough as
they are, but the garage is just double layer brickwork (no blockwork/
cavity).
In the upper storey access would be obtained by knocking through a
bathroom to make a short corridor into the new rooms.

I guess there are two ways to do it:
1) Increase foundation strength and put in blockwork.
2) Use an internal timber frame to support the additional weight of
the upper storey.

Assuming planning permission was granted (a risk to assume I know)
then I wondered on the approximate cost for this? Would anyone have
any idea how much to get the structural work done to a bare plaster
level?

Thanks
Marc

"marc_ely" wrote in message
ups.com...
Hi

We're in the process of house hunting and have come across a nice
place with room for improvement.

The property is about 20 years old and has an attached double garage.
To make more upstairs space I would like to build on top of the
garage.
The owner reckons the existing garage foundations are good enough as
they are, but the garage is just double layer brickwork (no blockwork/
cavity).
In the upper storey access would be obtained by knocking through a
bathroom to make a short corridor into the new rooms.

I guess there are two ways to do it:
1) Increase foundation strength and put in blockwork.
2) Use an internal timber frame to support the additional weight of
the upper storey.

Assuming planning permission was granted (a risk to assume I know)
then I wondered on the approximate cost for this? Would anyone have
any idea how much to get the structural work done to a bare plaster
level?

Thanks
Marc


I'm in the process of doing exactly this. Going through planning at the
moment.
Before I got plans drawn for planning, I dug 3 trial holes to expose the
footings and had Building Control have a look.
They seemed mostly interested in projection, ie., how far the footing comes
out from the wall. 150mm is good.

If the footings are not good then some sort of steel framework is needed or
underpinning. From what I could gather it would be cheaper to knock the lot
down and start from scratch than to underpin.

Your garage walls are unlikely to be the same overall thickness as what will
be required by Blg. Control for the new build as you'll need a cavity of say
75mm. That means you've got another little problem to resolve.
I suggest a couple of trial holes are the first step.


mark

Hi
Thanks for the helpful response.
So assuming you get your planning passed, what sort of price are you
looking at to complete the job?
Are you building a light block internal wall to meet the bldg reg air-
gap requirements?

Thanks
Marc

I'm in the process of doing exactly this. Going through planning at the
moment.
Before I got plans drawn for planning, I dug 3 trial holes to expose the
footings and had Building Control have a look.
They seemed mostly interested in projection, ie., how far the footing comes
out from the wall. 150mm is good.

If the footings are not good then some sort of steel framework is needed or
underpinning. From what I could gather it would be cheaper to knock the lot
down and start from scratch than to underpin.

Your garage walls are unlikely to be the same overall thickness as what will
be required by Blg. Control for the new build as you'll need a cavity of say
75mm. That means you've got another little problem to resolve.
I suggest a couple of trial holes are the first step.

mark

I haven't worked out the total cost. I will project manage my job so should
be cheaper than getting a builder.

The cost will consist of three elements:

1. Plans, Planning, Building regs. Say £1000

2. Labour

3. Materials

I am in the process of putting it all into a speadsheet. Guesses at first
then refining as I get better information.
Example:

Blockwork at say £7 per sq.m plus £12 sq.m to lay.
Windows supplied and fitted £1000
Scaffold £1000
Timber for roof £1000, carpenter £1000
Render external walls £1000
Roof tiles, battens, felt. £25/m plus labour.

Also cost in:-
Cement, nails, screws, sand, additives, wall ties etc.
Lintels, doorframes joists, floorboards, doors, plasterboard for ceilings.
Plumbing, electrics, skirting, architrave, internal rendering and
plastering, paint, window sills.

You'll soon get up to £20k

mark
























"marc_ely" wrote in message
oups.com...
Hi
Thanks for the helpful response.
So assuming you get your planning passed, what sort of price are you
looking at to complete the job?
Are you building a light block internal wall to meet the bldg reg air-
gap requirements?

Thanks
Marc

I'm in the process of doing exactly this. Going through planning at the
moment.
Before I got plans drawn for planning, I dug 3 trial holes to expose the
footings and had Building Control have a look.
They seemed mostly interested in projection, ie., how far the footing
comes
out from the wall. 150mm is good.

If the footings are not good then some sort of steel framework is needed
or
underpinning. From what I could gather it would be cheaper to knock the
lot
down and start from scratch than to underpin.

Your garage walls are unlikely to be the same overall thickness as what
will
be required by Blg. Control for the new build as you'll need a cavity of
say
75mm. That means you've got another little problem to resolve.
I suggest a couple of trial holes are the first step.

mark

Thanks for the information - the costs are about what I expected.
All the best.
Marc

Mark wrote:

Your garage walls are unlikely to be the same overall thickness as what will
be required by Blg. Control for the new build as you'll need a cavity of say
75mm. That means you've got another little problem to resolve.
I suggest a couple of trial holes are the first step.

If you built the top bit with studwork then you can meet the thermal
performance requirements easily enough in the thickness of a couple of
courses.

--
Cheers,

John.

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marc_ely wrote:

Assuming planning permission was granted (a risk to assume I know)

You can apply for outline PP on a place even if you don't own it. So you
could do that before committing to buy.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/