1978 two storey, upstairs is freezing in winter and the top of the stairs is a wind tunnel. Our utility offers a free walkthrough audit and there is a local firm quoting about 400 for a blower door test, thermal imaging and a written report. I do not need someone to hand me LED bulbs. Has anyone paid for the full test and can say what it found that a walkthrough would not have?
My paid audit came from a firm that also sold insulation and air sealing, and every finding pointed neatly at their most profitable service while the ducts went unmentioned. The second opinion I got later, from someone who only did testing, found the duct problem in twenty minutes. If you can find an assessor who does not sell the remediation, pay them instead.
Check the rebate side before you book anything. In our programme the audit was rebated in full if you went ahead with two or more of the recommended measures within a year, and the insulation rebate required a pre and post audit by an approved assessor anyway. So the paid audit effectively cost nothing and unlocked several thousand of measure rebates. Ring the programme before you ring the contractor.
Contrarian view: for a house with an obvious symptom like yours, you can find most of it yourself for the price of a takeaway. An infrared thermometer, a stick of incense on a windy day, and an afternoon in the loft with a torch will show you the attic hatch, the recessed lights, the top plates and the bulkhead. What you cannot do yourself is measure, so if you want a number to prove the work happened, pay. If you just want to know where to caulk, do not.
Half agree. DIY finds the obvious leaks, which is genuinely most of them by count. It does not find the ones behind finished surfaces or in ductwork, which in my house were most of them by volume.
Ask three questions when you book: do you do a blower door, do you do a duct test, and do I get the raw numbers. If the answer to the last one is a nice PDF with recommendations, you are buying a sales visit.
Practical timing note: book it for a cold snap if you can. Thermal imaging needs a decent temperature difference between inside and outside to show anything useful, and an assessor doing imaging on a mild autumn afternoon is largely wasting your money. Ours rescheduled us for exactly this reason and I respected them for it.
@venv_val · 6mo ago · 3 replies
Did both on the same house, six months apart, so this is a direct comparison.
Free utility walkthrough: LED bulbs, a low flow shower head, a pipe insulation sleeve, and a recommendation to add attic insulation. All fine, all things I knew.
Paid blower door and imaging: found that the attic hatch, three recessed light housings and the wall cavity behind the stair bulkhead were all open paths to the loft, and that a section of duct in the crawlspace had come apart entirely. It came with a before number and a target number for air changes, so the air sealing work had an outcome I could verify rather than a feeling.
After air sealing, the retest was dramatically tighter and the top of the stairs stopped being a wind tunnel. The insulation the free audit recommended would have been laid straight over the leaks and done very little.
Reply
Report
@lowtech_lior · 6mo ago
This is the point that keeps getting missed. Insulation over an unsealed ceiling plane is money set on fire. Air seal, then insulate, and the blower door is how you know which one you have got.
Reply
Report
@sashcord_stu · 6mo ago
The duct coming apart in a crawlspace is exactly the sort of thing I would never find. Booked.
Reply
Report