Ballpark cost to Extend house

[3littlefish]

I have a 4 bed semi + garage

If i wanted to
1 - convert garage
2 - build an ensuite bedroom over garage
3 - convert attic into ensuite bedroom and get rid of hibbed roof to max the attic space (+ big rear dormer windows etc)

What is the likely Max and Min I can expect to pay?
naturally it will vary depending on the finish and other variables but there must be some rough guide?

Anyone got any thoughts?

Thanks

 

[3littlefish]

I did have 1 reply that suggested in Dublin that it might cost about €100 per SqFt, but this reply appears to have disappeared for some reason.

Any other thoughts on a rought guide to building costs.

Before, an architect I knew told me that you can't "go upstairs" for under€100,000.

 

[bamboozle]

i've no idea pricewise but i presume you would need an architect & planning permission for that.

might be worth your while putting rough details on onlinetradesmen.com and see what rough figures people come back with.

 

[Mommah]

I asked my OH who was in the business.
He says its impossible to say based on the information you have given.

He says there are key cost drivers...for example if the existing garage structure is not fit to support a second floor...that will drive costs up ++.

The spec of your windows, doors, kitchen and bathrooms are a massive factor also.

Is there rear access...if not that increases costs as more man-handling required.

If the entire increase in size of the original house is less than 40sqm you generally don't need planning.

So you need to get an architect to draw up plans....having given them an idea of your budget...and then either get a builder or builders or a quantity surveyor to cost it.

 

[picorette]

Work out the area and apply €1,000 - €2,500 per square metre, but as Mommah says you will need to give much more detail to obtain accurate figures.
Each of those new rooms will require access from the main house as well.

 

[OCD]

Work out the area and apply €1,000 - €2,500 per square metre, but as Mommah says you will need to give much more detail to obtain accurate figures.
Each of those new rooms will require access from the main house as well.

OP, I would think €1800 to €2500 is more accurate for building costs. New builds are generally easier to construct and subsequently at the lower end of the scale but extensions and renovations usually require additional works to the structure, propping, underpinning, etc. and would be at the upper end of the scale for the new floor area and then €500 to €1500 for the renovated floor area depending on scale of rewiring, moving internal walls, insulation, decoration, etc.

Until you get plans drawn up it is almost impossible to put a very accurate figure on it. I would strongly suggest using an RIAI architect to get your plans done. The money you spend on them will be more than recouped by doing it the cheap way and having a builder price it for you!