Putting extension on house: which eco-measures to install?

S

stapler

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I will shortly be putting an extension (about 700 sq. ft.) onto my house (about 1700 sq. ft. currently). The house currently has an oil fired central heating system, about 10 years old.

Would it be worth considering any particular eco-measures, for example, solar panels, wood chip pellet boiler, etc., or is that only worth it if is a new build?
 
I'd be interested to hear that too.
PLanning a 40 sq m extension in the Spring & thinking of these things now
 
it depends on the quality of construction of the existing house.

You may be better off spending similar figures increasing the insulation standard of the existing dwelling. ie increased attic insulation, draugh stripping, insulate the attic access hatch, etc...
 
sydthebeat said:
it depends on the quality of construction of the existing house.

You may be better off spending similar figures increasing the insulation standard of the existing dwelling. ie increased attic insulation, draugh stripping, insulate the attic access hatch, etc...
Click to expand...

Hi Sydthebeat,

I'm trying to eliminate draughts in my windows..they're tilt and turn uPVC and basically they're rubbish, you can hear the wind whistling in through them! (if I won the lotto tomorrow i'd replace them straight away)....they've been adjusted and tightened on numerous occasions, even had a guy from the manufacturer here for 2 days but no major improvements....I've used EPDM self adhesive srtips on some of them but to no avail, can you recommend any product or come across any suppliers of such products that can help me?
 
I am doing something similar and after looking some research have decided to
1.replace the 10 year old oil boiler with a new condensing boiler
2.upgrade the insulation in the roof and walls
3.Reduce window openings on north elevation and replace with openings on west and South Elevation
4.Extend to the south of the building to maximise solar gain, using more than Building reg spec insulation and windows.
5.Replace PVC windows with lower uvalue timber windows
6.Install an efficient wood burning stove in main living area to reduce use of oil.

I decided against solar because it is not economic at present but may become so in the future. Wood pellet boilers are very expensive and you need somewhere to store the pellets. I felt spending money on insulation was more cost effective.
 
No to solar panels. Wood pellets - thats a big (huge) addition.
Yes to high density Insulation and argon gas k coated windows.

Do not do double insulation - ie insulation in the cavity and insulated plaster board.
 
hi,
please tell me why not double insulation?
We have put kingspan inside the cavity and now the plasterer suggests that we put 1 1/4 inch foam backed plasterboard .

also, a friend has suggested a condensed boiler - we do not have underfloor heating, will it still be good for us.

thanks very much
blob!
 
Hi BLOB,
Like yourself and Ramble we are currently looking at upgrading. For us it's a 70's Bungalow which we purchased a few years ago.
Our (current) main approach is:-
- Insulate attic with Kingspan/Xtratherm product (space restrictions is inhibiting us using other products such as pumped cellulose, hemp etc.)
- Dry line internal of external walls and underside of ceiling with insulation backed plasterboard (probably Poly-Iso). Btw I'm also keen to hear why sfag is against this.
- Upgrade windows to something more modern and efficient
- Attempt to make the house as airtight as possible
- Install a Heat Recovery System (we've already done this and are very pleased with it so far, I must write a separtate post on this)
- Redo some concrete floors as a previous upgrading of CH pipework has compromised the DPC resulting in damp in parts of the floor.
- Top up the bead insulation previously blown into the cavity as an inspection of this show many peaks and troughs along the wall.
- The small extension that we are building on will hopefully be of timber frame construction and be insulated with an eco product such as hemp.

The heating system is quite new so we wont need to change that for the time being, however I like the idea of wood pellet and am keeping an eye how it's going/developing here at the moment. It might be something for a few years time.
We are also re laying out some internal stuff, redoing bathrooms etc so it will be a builder project for the new year. And of course it goes without saying that this is the wish list and when we get quotes there may be a major change (downgrade) of plan.
All the best
Fran
 
BLOB said:
please tell me why not double insulation?
Click to expand...

Think about this.

Construction

Outer concrete block
40 mm gap
60 mm polyiso type insulation
inner concrete block
25 mm polyiso type insulation
plasterboard

Any dampness, water that gets into or around your inner block will not be able to escape because of the polyiso on either side which is impenetrable to moisture. Moisture can rise up from poor workmanship on damp proof course at foundation level, leak around windows or items bridging cavity. Wind driven rain can penetrate plaster and outer block, move across cavity on ties etc etc. It just might make your inner block nice and warm and wet.

This is just my opinion. Would be much better to go for the larger cavity.

Also your internal leaf, concrete only, acts as a heat store during the day and releases it at night, if you insulate your wall internally you loose that.

 
cookie1 said:
Hi Sydthebeat,

I'm trying to eliminate draughts in my windows..they're tilt and turn uPVC and basically they're rubbish, you can hear the wind whistling in through them! (if I won the lotto tomorrow i'd replace them straight away)....they've been adjusted and tightened on numerous occasions, even had a guy from the manufacturer here for 2 days but no major improvements....I've used EPDM self adhesive srtips on some of them but to no avail, can you recommend any product or come across any suppliers of such products that can help me?
Click to expand...

sorry cookie, i havent actually come across anything.....
I assume the windows are upvc, so rebated EPDM gaskets wouldnt work....

ive no advice short of replacing them..... or investing in thick curtains that you pull every evening....
 
Franm

- Top up the bead insulation previously blown into the cavity as an inspection of this show many peaks and troughs along the wall.
Click to expand...


How was the inspection done?
Have the same stuff in our walls since before we bought the house 5 years ago and I have often wondered what state the insulation is in.
 
The inspection between the walls happened by accident really.
I was removing a vent (as part of the HRV install) and decided to take a picture with our small digital camera. This showed that the bead was not going the full height and contained many peaks and troughs. My guess is that it's the same in the other walls.
I also wonder if some sort of thermal image photography would also show up this.
Regards
Fran
 
Ive just finished extension, full 40 sq metres. Fitted 4 Fakro triple glazed skylights that were about the same price as the Velux double glazed equivalents. Fantastic as keeping noise out and keepong heat i so far anyway. Can bearly hear the rain... No connection to company except very happy customer.
 
A couple of posters said no to solar panels?
Can I ask why?

I was thinking about putting them on the roof of my extension to heat the hot water.
Is this not a good idea?
It'd be a south facing sloped roof.
 
frash, solar collectors are a great inclusion.....
proper vaccuum tube type will give you as much hot water as you will need for at least 5 months of the year and a high percentage for the rest of the year.... they are a no-brainer
 
I am curious to know too why one would not install solar panels when putting an extension onto a house? About how much do they cost to put in?
 
Solar panels are expensive, a solar system to serve a household of 6 costs about €10,000. €10,000 buys a lot of insulation and a new efficient oil boiler costs only €1,200. The payback time on solar is about 10 years and there is no guarantee that the panels available now will last more than 10 years. Why pay for 10 years of hot water up front, especially if you are borrowing the money? The payback time on a new boiler is 3 years and it will last at least 10 years. So if money is no object solar is great but on a budget it makes more sense to spend the money on less expensive energy saving measures with a shorter payback. If energy costs go up substantially or the cost of solar comes down then it will be time to reconsider.
 
€10,000...!!!!!
With solar collectors currently available for as cheap as €300, you seem to have paid way above standard prices... i hope you are not including all the accessories and labour costs that you would have with a traditional system... obviously these are not included when quoting the price difference betwen the two systems.....
generally 6 sq m of solar collectors, and necessary accessories, should cost a price difference of no more than €5500... remove from this a grant of 1500 and you are looking at an initial cost of 4000 max.
 
I didn't go for it because of the cost. The house already has a heating/hotwater system so the solar would have to be installed alongside with a new large storage tank and connections to existing system. Even at 4 -5000 euro you are still looking at 10 years hot water costs up front and it wont supply all your hot water.
 
ramble said:
I didn't go for it because of the cost. The house already has a heating/hotwater system so the solar would have to be installed alongside with a new large storage tank and connections to existing system. Even at 4 -5000 euro you are still looking at 10 years hot water costs up front and it wont supply all your hot water.
Click to expand...

you are assuming heating costs will not rise???
what if it was put to you that theres a strong possibility that oil / gas prices will be double they are now.....
solar hot water will seem like a god send at that stage.......
 
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