25sqm rear extension

goz83

Hi lads. I've been playing around with a few ideas on extending the house and will be almost certainly getting a rear kitchen extension this year. The current kitchen area is 5m wide and 3m long. I plan to extend out 5m, so the extension will be 25sqm internally. I will be left with a garden of approx 30sqm after I rip down the existing block shed. I have drawn up some basic plans using sketchup and was hoping to get some feedback and realistic costing, using the info and images below. I am looking for builders finish, with good insulation. I will price flooring and paint separately.



The image above is focusing on the current kitchen area (the orange bit). The transparent beams represent the current structural beam which separates the current kitchen and dining area and also the current structural support above the windows and door, which are of course not part of the drawing.I am pretty certain that an rsj will be needed, because the back wall is getting knocked through completely.

The rectangle on the wall, touching the floor and beam is the soil stack.



This image shows you what I am thinking, design wise. I want to get good light into the room and into the existing kitchen. Ignore the pond on the left and the back yard in general. The neighbouring house can be seen on the left (I was too lazy to draw windows). It is the way my house currently is (but reversed). The sewage pipe runs along the back of the houses, maybe 2ft from the back of the house. My house is the end junction for 4, or maybe 6 houses. The junction is just to the rear of the current side access and half of the cover plate goes into the other neighbours property (on the boundary to the right). The side access has a roof and I plan to extend this the full length of the extension (but will price separately).

The french doors are 2mx2.25m. The side windows are approx 1mx1.8m. I haven't measured the "A" windows and I am looking for advice on this window design and guesstimate costs. I will be getting 4 skylights. I think double glaze will be good enough, but open to suggestions.



Inside view. Ignore bottom right...it's just a flaw in the drawing because of the pond.

I am not sure what finish will be done, but will likely be dashing. The current dashing job is quite poor and dull, so can anyone give a price for a dash finish (to include upper floor area of course).

Other info:

The boiler will remain in the same place, beside the soil stack, but the sink will be moved a few feet. The gas oven connection is currently about 5ft from the soil stack on the side wall, but the connection will need to be moved over to the wall currently separating the sitting room. This is a solid wall. I will also be extending the under the stairs space to accommodate a toilet, small sink and most likely a shower. This can be seen in the first image, where the area extends into the kitchen. I will price this separately.

Opinions/suggestions very welcome. What am I looking at cost wise for the builders finish I mentioned?

jay0109

From a recent extension job in Sth Dub, €175 per sq ft

goz83

jay0109 wrote: »

From a recent extension job in Sth Dub, €175 per sq ft

I can't see it costing 47k, unless the windows above the door are costing 10k. That's almost €1900 per sqm, which is very high. I know I am asking here, but I am expecting a per metre price of no more than €1500 and preferably closer to the 1k mark. The only complication with the extension is sewage pipe behind the house. I don't know if it gets moved, or built over, as the main manhole cover will remain free.

This extension will be north dublin and I am just looking for builders finish, nothing fancy. Does anything look expensive from the drawing?

KK4SAM

I though you had to be 600 mm from a boundary wall ?

goz83

KK4SAM wrote: »

I though you had to be 600 mm from a boundary wall ?

Not from what I have seen, which includes some of the local front of house extensions built up to and sometimes replacing the boundary wall. The houses to the right of me both have the same size rear extension and they are connected together.

That would also create a perfect gap for debris and vermin

Gumbo

KK4SAM wrote: »

I though you had to be 600 mm from a boundary wall ?

Any windows have to be 1m from the boundary at ground floor level.
The block wall can run right up to the boundary.


25 Sq. M extension To builders finish = 35k depending on if plastered or painted?
On top of that - floor finishes, kitchen windows.
The windows you have shown are not complex and not expensive, there are no large open so it's just French doors, fixed panels and the tri-angular pieces are about 1100-1500 each.

The thing here that will add to your average cost request is the additional steel required to hold the roof up, creating that spec with no horizontal ties in order to make the high level windows worthwhile.

Gumbo

goz83 wrote: »

I can't see it costing 47k, unless the windows above the door are costing 10k. That's almost €1900 per sqm, which is very high. I know I am asking here, but I am expecting a per metre price of no more than €1500 and preferably closer to the 1k mark. The only complication with the extension is sewage pipe behind the house. I don't know if it gets moved, or built over, as the main manhole cover will remain free.

This extension will be north dublin and I am just looking for builders finish, nothing fancy. Does anything look expensive from the drawing?

With all due respect, if your going to dismiss people's rough calculations on here then the only thing to due is to get quotes from builders in the real world.

I don't think you'll have any change from 50k when your finished here either.

The 4 Velux windows (78x98) are €500 each alone.
You'll have drainage diversion and/or encasement with the creation of rodding access.

What do you class as builders finish? What level do you want the builder to step back at?

goz83

kceire wrote: »

With all due respect, if your going to dismiss people's rough calculations on here then the only thing to due is to get quotes from builders in the real world.

I don't think you'll have any change from 50k when your finished here either.

The 4 Velux windows (78x98) are €500 each alone.
You'll have drainage diversion and/or encasement with the creation of rodding access.

What do you class as builders finish? What level do you want the builder to step back at?

My simple understanding is that the PPM is impacted depending on the finish required. Beer mat guess for bare bones finish €1000 per sqm and highest quality would be €2000 per sqm. I am aiming for middle of the road pricing on the build, so guessing 1500 per sqm. Based on this, I can't see the cost being 50k until everything else is added (windows, floors etc). I wasn't dismissing the other post, I was questioning the price, as I was unsure of some of the things that could increase the cost (windows, steel etc). There was no explanation to the price given, other than it was based on a recent south dublin extension. I already have french doors and will likely reuse those unless I am getting triple glaze.

What I mean by builders finish is that the extension is build right up to plastering/rendering and the electrics are in place.

The separate costings will be painting, floor tiling, fitting lights and kitchen installation. I excluded these, because I can price them myself depending on the final design choices and we all know that prices of kitchens and even the prices of tiles can vary hugely.

Gumbo

goz83 wrote: »

My simple understanding is that the PPM is impacted depending on the finish required. Beer mat guess for bare bones finish €1000 per sqm and highest quality would be €2000 per sqm. I am aiming for middle of the road pricing on the build, so guessing 1500 per sqm. Based on this, I can't see the cost being 50k until everything else is added (windows, floors etc). I wasn't dismissing the other post, I was questioning the price, as I was unsure of some of the things that could increase the cost (windows, steel etc). There was no explanation to the price given, other than it was based on a recent south dublin extension. I already have french doors and will likely reuse those unless I am getting triple glaze.

What I mean by builders finish is that the extension is build right up to plastering/rendering and the electrics are in place.

The separate costings will be painting, floor tiling, fitting lights and kitchen installation. I excluded these, because I can price them myself depending on the final design choices and we all know that prices of kitchens and even the prices of tiles can vary hugely.

Cool. I didn't mean to sound smart if my post came across that way either.
Builders finish in my opinion is structurally complete, weather tight, skimmed and ready for paint with sockets fitted and light pendants fitted.

Allow €50 per square meter for supply and fit of tiles based on my recent experience in north Dublin.

My most recent tender for a 44 sq. m extension, with refurbishment of existing ground floor is €89k. That's inclusive of vat and includes windows, laying of tiles only that are supplied by client and re render elevations of existing house. That was €1880 per sq. m but you should be a lot less as you are doing less.

Are you going to get a contractor or self build and engage the trades yourself?

goz83

kceire wrote: »

Are you going to get a contractor or self build and engage the trades yourself?

I haven't decided yet. My father in law is a builder, but he is in his sixties and has recently decided to stop taking on larger jobs (such as extensions). He tends to take twice as long to do the work, but it's always a good finish. So, will see if he is up for it if I can get some labour in to help.

Otherwise I will engage the trades myself in an effort to keep costs reasonable. I work from home, so makes it easier. I also owned a mixed trade company a few years ago and have a little bit of experience in organising, delegating and getting good prices. I always do loads of research first....especially when spending thousands. Boards is always a great source for info.