“I spent two years dreading the back of my house.” How one 1.8m bifold set fixed a dark kitchen — and passed Part Q

Our kitchen faces north-east. For two years it had a pair of tired uPVC French doors that leaked heat, rattled in the wind and made the whole room feel like a corridor. We had a builder's quote for a full supply-and-fit bifold at just over £6,800. That was the point at which I started looking at pre-manufactured sets instead.

What I kept coming back to was the Part Q 1800mm Grey Aluminium Bifold Doors – 3 Left from Climadoor. It is a 1800mm (6ft) three-panel set, all three leaves folding to the left, supplied as frame, leaves and sealed units with the hardware already fitted. Crucially for us — the extension was signed off under current regulations — it is Part Q compliant, which is the security standard building control cares about on new dwellings.

What you actually get in the crate

Two pallets arrived on a Tuesday morning, wrapped and cornered properly. The frame comes in four lengths with the 167mm cill & threshold pre-machined, and the three leaves come glazed. That last part matters more than it sounds: glazing a bifold leaf on site with a laminated unit is a two-person, one-swear-word-per-pane job. Here the glass was already in, the gaskets were seated, and the hinges, rollers and the PAS 24 multipoint lock were factory-fitted.

The frame is thermally broken aluminium — a polyamide bridge separating the inner and outer profiles — finished in anthracite grey, which reads as a slightly warm dark grey rather than the blue-black you sometimes get on cheaper powder coats. Handles and hinges are black, and they match.

Part Q, PAS 24 and the bit people skip

If you are building new — an extension counts in many cases — Approved Document Q sets a minimum security standard for doors and windows accessible from outside. This set is specified against it: PAS 24 rated multipoint locking and laminated security glazing rather than plain toughened. The practical difference is that laminated glass holds together in the frame when it is struck. Our building control officer asked for the certification paperwork, it came with the doors, and that was the end of the conversation.

Worth saying plainly: Part Q compliance is a property of the door and its installation. If you pack the frame badly or fix into crumbling blockwork, the certificate on the paperwork will not save you. Ours went into a fresh opening at 1805 × 2105mm, packed and fixed to the manufacturer's pattern.

Does it actually keep the heat in?

The sealed units are quoted at 1.0 W/m²K, with a whole-set figure of 1.4 W/m²K once the aluminium is taken into account. That meets the 1.4 refurbishment threshold in Part L, and it is a world away from the doors we took out. Anecdotally: the room used to be the one you put a jumper on for. Through January the kitchen sat within about a degree of the hallway, and there was no condensation running down the inside of the glass on cold mornings — the thermal break is doing its job.

I would not pretend a large glazed opening is thermally better than a wall. It isn't. But if you are replacing glazing with glazing, this is the right end of the market, and it is one of the reasons we did not go for a cheaper non-thermally-broken system.

The weekend fit — realistically

Climadoor quote under a day for a three-door system into a prepared opening. With two of us, a laser level and no prior bifold experience, it took a long Saturday plus a Sunday morning of adjustment. The sequence was: dry-fit the cill, level and pack, fix the outer frame, hang the leaves, then spend an hour on the hinge adjustment until the shoot bolts drop without being persuaded.

• Get the opening right first. 1805 × 2105mm gives you working clearance. Ours was 8mm out across the head and it cost us an hour.
• Two people minimum. A glazed aluminium leaf is not heavy so much as awkward and expensive.
• Don't skip the adjustment. Bifolds are a running system. Ten minutes with the hinge grub screws is the difference between a door that glides and one you shoulder.
• Trickle vents. The set is supplied Part F compliant — check your ventilation strategy with building control before you order, not after.

What I'd flag before you buy

Three things. First, the 10–15 working days lead time is real — order before your opening is formed, not after, or you will have a hole in your wall and a tarpaulin. Second, this is a standard-size set; if your opening is not close to 1805 × 2105mm you are into made-to-measure, which costs more and takes longer. Third, delivery is kerbside. Have two people and somewhere dry.

None of that is a criticism of the product. It is the difference between buying a pre-manufactured set and paying a company £6,800 to worry on your behalf.

Full specification

The verdict

Nine months in, the doors open with one hand, the lock is still crisp, and the finish has taken a winter of driving rain without a mark. For £2,099.00 you are getting a thermally broken, Part Q compliant, factory-glazed set with a 20-year frame guarantee. If your opening suits a standard size and you have a competent pair of hands, it is very hard to argue with.