Deep Retro-fit.

That's really interesting. Would you mind detailing what the three top issues in that house were?

I'm guessing things like External doors? Light fixtures? Floors?
No.1 by a country mile was the t&g timber ceilings in several areas
Next was several (5no) crawl space access doors/hatches (it was a dormer)
No.3 was upstairs floor and floor to knee wall junctions (as often occurs in these cases, the upstairs carpet lifted a couple inches off the floor due to the pressure of the incoming air)
 
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What equates to 'decent' amount of work. The other options I see are

1. Insulate between the floorboards, though I'd rather just seal holes and use good insulating underlay on ground floor.
2. Insulate the roof space
3. Insulate between the walls / or some form of internal wall insulation.

Don't confuse insulation with air-tightness. For suspended timber floors, you would need to lift them insulate and seal all joints and around all edges. After that, look at all the obvious leakage points like external doors and windows, attic hatches, skirting, electrical fittings, switches, and all points where cables or pipes travel through walls or ceilings. Look for any cracks in walls or ceilings. To me, unless you address all of the above, an air-tightness test is a waste of money.
 
Expect to pay in around 5 to 600 to include a comprehensive report
What sort of reduction in a heating bill would you experience going from 1960s level air "tightness" to a decent standard nowadays, everything else being equal. €5-600 would almost cover our gas bill for a year.
 
Don't confuse insulation with air-tightness. For suspended timber floors, you would need to lift them insulate and seal all joints and around all edges. After that, look at all the obvious leakage points like external doors and windows, attic hatches, skirting, electrical fittings, switches, and all points where cables or pipes travel through walls or ceilings. Look for any cracks in walls or ceilings. To me, unless you address all of the above, an air-tightness test is a waste of money.

Here's what I don't understand. You go to this level of detail, and then drill bloody great holes in the walls as vents. What's the point? I understand if you're intending to build to passive house standards, to mechanical ventilation etc. But if not, why bother going beyond sealing floors, doors, windows?
 
To me, unless you address all of the above, an air-tightness test is a waste of money.
I find the opposite because prior to the test, the owners are unaware to the extent of the leakage rates and the impact these are having on their heat loss. A also find the test itself is a definite "eye opener" and have been told this on a very frequent basis.
 
What sort of reduction in a heating bill would you experience going from 1960s level air "tightness" to a decent standard nowadays, everything else being equal. €5-600 would almost cover our gas bill for a year.

... how long is a piece of string... it depends on a whole lot of things not least how warm you keep the house in general. What I find It quite often especially in cases where there is high air leakage to start off with is that some of the heat retention improvement dividend is absorbed in a warmer home i.e. the house is allowed to get a degree or two higher for longer because there is less perception of waste.

Where the test/survey is really valuable, I think, is it takes the guesswork out of where to spend your money or not.
 
Here's what I don't understand. You go to this level of detail, and then drill bloody great holes in the walls as vents. What's the point? I understand if you're intending to build to passive house standards, to mechanical ventilation etc. But if not, why bother going beyond sealing floors, doors, windows?
You don't. "hole in wall" vents are proven time and again to be not fit for purpose in any kind of reasonably airtight house (say <5 m3/hr/m2@50). You generally need some form of a properly designed mechanical ventilation system.
In my opinion and given our moderate climate, this is still a major flaw in our building regulations.
 
You don't. "hole in wall" vents are proven time and again to be not fit for purpose in any kind of reasonably airtight house (say <5 m3/hr/m2@50). You generally need some form of a properly designed mechanical ventilation system.
In my opinion and given our moderate climate, this is still a major flaw in our building regulations.

What sort of cost are you looking at for mechanical ventilation? 4 bed, 1800sq ft. Any ideas?
 
It's nearly like asking what sort of cost for a family car there's so much it depends on but anything from 1.5 to 6k I would think.

Thanks. I kind of knew it was a bit of a daft question. Feels like peeling an orange this refurb stuff. Like, you could go with not spending too much on airtightness, or ventilation. But if you go bananas on air tightness then you need to actively solve for ventilation issues that creates. I know the ultimate output of the more expensive approach is far superior...cheaper to run, healthier, more env friendly etc. But if it adds 20k to the price tag, its a fair chunk of change in overall budget.
 
Thanks. I kind of knew it was a bit of a daft question. Feels like peeling an orange this refurb stuff. Like, you could go with not spending too much on airtightness, or ventilation. But if you go bananas on air tightness then you need to actively solve for ventilation issues that creates. I know the ultimate output of the more expensive approach is far superior...cheaper to run, healthier, more env friendly etc. But if it adds 20k to the price tag, its a fair chunk of change in overall budget.
For sure. you need to strike a balance but be certain you don't solve one problem and create another especially when it come to moisture control.
That's where a targeted approach based on an in-depth examination or survey of the building comes into its own plus an understanding that there are always compromises to be made especially when it comes to budget. The key is to make the correct decisions based on relevant information / data.
 
Thanks Mick. Last questions.....I think! For a significant refurb, presume you're doing the examination rather than survey? i.e. you have a target for airtightness, then plan and design with architect (and any other professional as required) based on this, and then design ventilation solution appropriate.

I can see now how important it is to get the design and plan stage right, and then the execution - for a thorough refurb there is no airtight test possible/relevant until most of the work is done, at which point the work in relation to airthightness would already need to have been factored in.
 
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Here's what I don't understand. You go to this level of detail, and then drill bloody great holes in the walls as vents. What's the point? I understand if you're intending to build to passive house standards, to mechanical ventilation etc. But if not, why bother going beyond sealing floors, doors, windows?

There's a balance between effective ventilation and lots of uncontrolled leaks resulting in drafty rooms. But you're right, going all out and spending big money on achieving air-tightness is a waste of money without mechanical heat-recovery ventilation.
 
I find the opposite because prior to the test, the owners are unaware to the extent of the leakage rates and the impact these are having on their heat loss. A also find the test itself is a definite "eye opener" and have been told this on a very frequent basis.

I'd consider charging €5-600 on a test to point out the obvious as veering dangerously towards an exercise in gouging. It would be far better if people were educated on how they can spend less money on fixing a few of the most common issues.
 
I'd consider charging €5-600 on a test to point out the obvious as veering dangerously towards an exercise in gouging. It would be far better if people were educated on how they can spend less money on fixing a few of the most common issues.
To point out the obvious? That's the whole point, it's not obvious to the average person where the real issues are and how to address them. This is what I'm told by clients on a very regular basis. Comments such as "you have completely changed my thinking on where my problems are" are not uncommon.

On the gouging question, when you consider that travel time to and from a property of say up to 4 hours, 6 hours for the survey and discussion with the home owner on best way to proceed plus the writing of the bespoke report (3 hours min in the office) then possible followup phone consultation (included in the price) into the future, I'd argue that it is in fact very good value for money. Also include in the equation insurance / equipment maintenance, calibration & depreciation / other fixed costs / profit plus the fact that a proper survey can only be done effectively during the heating season. One thing's for sure, I ain't getting rich from my "gouging".

Yes I agree, education is key especially for homeowners who should then demand better standards from the industry. Problem is though that the construction industry is riddled with conflicts of interest so who does the educating of the public?
 
To point out the obvious? That's the whole point, it's not obvious to the average person where the real issues are and how to address them.

It should be obvious to anyone working in this line that a 50 year old suspended timber floor is going to be a major issue. Likewise with old poorly fitting loft hatches, poorly sealing windows and doors. All these elements are factored into the BER calculations with sufficient accuracy from a visual inspection without no need for expensive blower tests.
 
Just discovered this very interesting document about BER ratings and practicalities for historic houses, published by the Irish Georgian Society which may be of interest to @candor [broken link removed] - @Leo and @Micks'r may be interested to see that they do recommend ventilation tests in one of the papers because this is often the most efficient thing you can do in a historic building - but they also point out things like, the U-ratings are a big underestimate for old stone walls as they do not factor in 60 cm v 20 cm thickness for example (Historic Scotland tried to produce a proper set of U-ratings for old houses, but the civil servants in the UK rejected their calculations).
 
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